Plant breeding

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Plant_breeding

 

See also: Cultigen and Cultivar

 

The Yecoro wheat (right) cultivar is sensitive to salinity, plants resulting from a hybrid cross with cultivar W4910 (left) show greater tolerance to high salinity

Plant breeding is the science of changing the traits of plants in order to produce desired characteristics. It has been used to improve the quality of nutrition in products for humans and animals. The goals of plant breeding are to produce crop varieties that boast unique and superior traits for a variety of applications. The most frequently addressed agricultural traits are those related to biotic and abiotic stress tolerance, grain or biomass yield, end-use quality characteristics such as taste or the concentrations of specific biological molecules (proteins, sugars, lipids, vitamins, fibers) and ease of processing (harvesting, milling, baking, malting, blending, etc.).

Plant breeding can be performed through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to methods that make use of knowledge of genetics and chromosomes, to more complex molecular techniques. Genes in a plant are what determine what type of qualitative or quantitative traits it will have. Plant breeders strive to create a specific outcome of plants and potentially new plant varieties, and in the course of doing so, narrow down the genetic diversity of that variety to a specific few biotypes.

It is practiced worldwide by individuals such as gardeners and farmers, and by professional plant breeders employed by organizations such as government institutions, universities, crop-specific industry associations or research centers. International development agencies believe that breeding new crops is important for ensuring food security by developing new varieties that are higher yielding, disease resistant, drought tolerant or regionally adapted to different environments and growing conditions.

A recent study shows that without plant breeding, Europe would have produced 20% fewer arable crops over the last 20 years, consuming an additional 21.6 million hectares (53 million acres) of land and emitting 4 billion tonnes (3.9×10⁹ long tons; 4.4×10⁹ short tons) of carbon. Wheat species created for Morocco are currently being crossed with plants to create new varieties for northern France. Soy beans, which were previously grown predominantly in the south of France, are now grown in southern Germany.

History

Main article: History of plant breeding

Plant breeding started with sedentary agriculture and particularly the domestication of the first agricultural plants, a practice which is estimated to date back 9,000 to 11,000 years. Initially early farmers simply selected food plants with particular desirable characteristics, and employed these as progenitors for subsequent generations, resulting in an accumulation of valuable traits over time.

Grafting technology had been practiced in China before 2000 BCE.

By 500 BCE grafting was well established and practiced.

Gregor Mendel (1822–84) is considered the "father of genetics". His experiments with plant hybridization led to his establishing laws of inheritance. Genetics stimulated research to improve crop production through plant breeding.

Modern plant breeding is applied genetics, but its scientific basis is broader, covering molecular biology, cytology, systematics, physiology, pathology, entomology, chemistry, and statistics (biometrics). It has also developed its own technology.

Classical plant breeding

For the role of crossing and plant breeding in viticulture, see Propagation of grapevines.

Selective breeding enlarged desired traits of the wild cabbage plant (Brassica oleracea) over hundreds of years, resulting in dozens of today's agricultural crops. Cabbage, kale, broccoli, and cauliflower are all cultivars of this plant.

One major technique of plant breeding is selection, the process of selectively propagating plants with desirable characteristics and eliminating or "culling" those with less desirable characteristics.

Another technique is the deliberate interbreeding (crossing) of closely or distantly related individuals to produce new crop varieties or lines with desirable properties. Plants are crossbred to introduce traits/genes from one variety or line into a new genetic background. For example, a mildew-resistant pea may be crossed with a high-yielding but susceptible pea, the goal of the cross being to introduce mildew resistance without losing the high-yield characteristics. Progeny from the cross would then be crossed with the high-yielding parent to ensure that the progeny were most like the high-yielding parent, (backcrossing). The progeny from that cross would then be tested for yield (selection, as described above) and mildew resistance and high-yielding resistant plants would be further developed. Plants may also be crossed with themselves to produce inbred varieties for breeding. Pollinators may be excluded through the use of pollination bags.

Classical breeding relies largely on homologous recombination between chromosomes to generate genetic diversity. The classical plant breeder may also make use of a number of in vitro techniques such as protoplast fusion, embryo rescue or mutagenesis (see below) to generate diversity and produce hybrid plants that would not exist in nature.

Traits that breeders have tried to incorporate into crop plants include:

1. Improved quality, such as increased nutrition, improved flavor, or greater beauty
2. Increased yield of the crop
3. Increased tolerance of environmental pressures (salinity, extreme temperature, drought)
4. Resistance to viruses, fungi and bacteria
5. Increased tolerance to insect pests
6. Increased tolerance of herbicides
7. Longer storage period for the harvested crop

Before World War II

Garton's catalogue from 1902

Successful commercial plant breeding concerns were founded from the late 19th century. Gartons Agricultural Plant Breeders in England was established in the 1890s by John Garton, who was one of the first to commercialize new varieties of agricultural crops created through cross-pollination. The firm's first introduction was the Abundance Oat, an oat variety. It is one of the first agricultural grain varieties bred from a controlled cross, introduced to commerce in 1892.

In the early 20th century, plant breeders realized that Gregor Mendel's findings on the non-random nature of inheritance could be applied to seedling populations produced through deliberate pollinations to predict the frequencies of different types. Wheat hybrids were bred to increase the crop production of Italy during the so-called "Battle for Grain" (1925–1940). Heterosis was explained by George Harrison Shull. It describes the tendency of the progeny of a specific cross to outperform both parents. The detection of the usefulness of heterosis for plant breeding has led to the development of inbred lines that reveal a heterotic yield advantage when they are crossed. Maize was the first species where heterosis was widely used to produce hybrids.

Statistical methods were also developed to analyze gene action and distinguish heritable variation from variation caused by environment. In 1933 another important breeding technique, cytoplasmic male sterility (CMS), developed in maize, was described by Marcus Morton Rhoades. CMS is a maternally inherited trait that makes the plant produce sterile pollen. This enables the production of hybrids without the need for labor-intensive detasseling.

These early breeding techniques resulted in large yield increase in the United States in the early 20th century. Similar yield increases were not produced elsewhere until after World War II, the Green Revolution increased crop production in the developing world in the 1960s.

After World War II

In vitro-culture of Vitis (grapevine), Geisenheim Grape Breeding Institute

Following World War II a number of techniques were developed that allowed plant breeders to hybridize distantly related species, and artificially induce genetic diversity.

When distantly related species are crossed, plant breeders make use of a number of plant tissue culture techniques to produce progeny from otherwise fruitless mating. Interspecific and intergeneric hybrids are produced from a cross of related species or genera that do not normally sexually reproduce with each other. These crosses are referred to as Wide crosses. For example, the cereal triticale is a wheat and rye hybrid. The cells in the plants derived from the first generation created from the cross contained an uneven number of chromosomes and as a result was sterile. The cell division inhibitor colchicine was used to double the number of chromosomes in the cell and thus allow the production of a fertile line.

Failure to produce a hybrid may be due to pre- or post-fertilization incompatibility. If fertilization is possible between two species or genera, the hybrid embryo may abort before maturation. If this does occur the embryo resulting from an interspecific or intergeneric cross can sometimes be rescued and cultured to produce a whole plant. Such a method is referred to as embryo rescue. This technique has been used to produce new rice for Africa, an interspecific cross of Asian rice Oryza sativa and African rice O. glaberrima.

Hybrids may also be produced by a technique called protoplast fusion. In this case protoplasts are fused, usually in an electric field. Viable recombinants can be regenerated in culture.

Chemical mutagens like ethyl methanesulfonate (EMS) and dimethyl sulfate (DMS), radiation, and transposons are used for mutagenesis. Mutagenesis is the generation of mutants. The breeder hopes for desirable traits to be bred with other cultivars – a process known as mutation breeding. Classical plant breeders also generate genetic diversity within a species by exploiting a process called somaclonal variation, which occurs in plants produced from tissue culture, particularly plants derived from callus. Induced polyploidy, and the addition or removal of chromosomes using a technique called chromosome engineering may also be used.

Agricultural research on potato plants

When a desirable trait has been bred into a species, a number of crosses to the favored parent are made to make the new plant as similar to the favored parent as possible. Returning to the example of the mildew resistant pea being crossed with a high-yielding but susceptible pea, to make the mildew resistant progeny of the cross most like the high-yielding parent, the progeny will be crossed back to that parent for several generations (See backcrossing). This process removes most of the genetic contribution of the mildew resistant parent. Classical breeding is therefore a cyclical process.

With classical breeding techniques, the breeder does not know exactly what genes have been introduced to the new cultivars. Some scientists therefore argue that plants produced by classical breeding methods should undergo the same safety testing regime as genetically modified plants. There have been instances where plants bred using classical techniques have been unsuitable for human consumption, for example the poison solanine was unintentionally increased to unacceptable levels in certain varieties of potato through plant breeding. New potato varieties are often screened for solanine levels before reaching the marketplace.

Even with the very latest in biotech-assisted conventional breeding, incorporation of a trait takes an average of seven generations for clonally propagated crops, nine for self-fertilising, and seventeen for cross-pollinating.

Modern plant breeding

See also: New Breeding Techniques

Modern plant breeding may use techniques of molecular biology to select, or in the case of genetic modification, to insert, desirable traits into plants. Application of biotechnology or molecular biology is also known as molecular breeding.

Modern facilities in molecular biology are now used in plant breeding.

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Marker assisted selection

Main article: Marker assisted selection

Sometimes many different genes can influence a desirable trait in plant breeding. The use of tools such as molecular markers or DNA fingerprinting can map thousands of genes. This allows plant breeders to screen large populations of plants for those that possess the trait of interest. The screening is based on the presence or absence of a certain gene as determined by laboratory procedures, rather than on the visual identification of the expressed trait in the plant. The purpose of marker assisted selection, or plant genome analysis, is to identify the location and function (phenotype) of various genes within the genome. If all of the genes are identified it leads to genome sequence. All plants have varying sizes and lengths of genomes with genes that code for different proteins, but many are also the same. If a gene's location and function is identified in one plant species, a very similar gene likely can also be found in a similar location in another related species genome.

Reverse breeding and doubled haploids (DH)

Main article: Doubled haploidy

Homozygous plants with desirable traits can be produced from heterozygous starting plants, if a haploid cell with the alleles for those traits can be produced, and then used to make a doubled haploid. The doubled haploid will be homozygous for the desired traits. Furthermore, two different homozygous plants created in that way can be used to produce a generation of F1 hybrid plants which have the advantages of heterozygosity and a greater range of possible traits. Thus, an individual heterozygous plant chosen for its desirable characteristics can be converted into a heterozygous variety (F1 hybrid) without the necessity of vegetative reproduction but as the result of the cross of two homozygous/doubled haploid lines derived from the originally selected plant. Plant tissue culturing can produce haploid or double haploid plant lines and generations. This cuts down the genetic diversity taken from that plant species in order to select for desirable traits that will increase the fitness of the individuals. Using this method decreases the need for breeding multiple generations of plants to get a generation that is homogeneous for the desired traits, thereby saving much time over the natural version of the same process. There are many plant tissue culturing techniques that can be used to achieve haploid plants, but microspore culturing is currently the most promising for producing the largest numbers of them.

Genetic modification

Main article: Transgenic plants

Genetic modification of plants is achieved by adding a specific gene or genes to a plant, or by knocking down a gene with RNAi, to produce a desirable phenotype. The plants resulting from adding a gene are often referred to as transgenic plants. If for genetic modification genes of the species or of a crossable plant are used under control of their native promoter, then they are called cisgenic plants. Sometimes genetic modification can produce a plant with the desired trait or traits faster than classical breeding because the majority of the plant's genome is not altered.

To genetically modify a plant, a genetic construct must be designed so that the gene to be added or removed will be expressed by the plant. To do this, a promoter to drive transcription and a termination sequence to stop transcription of the new gene, and the gene or genes of interest must be introduced to the plant. A marker for the selection of transformed plants is also included. In the laboratory, antibiotic resistance is a commonly used marker: Plants that have been successfully transformed will grow on media containing antibiotics; plants that have not been transformed will die. In some instances markers for selection are removed by backcrossing with the parent plant prior to commercial release.

The construct can be inserted in the plant genome by genetic recombination using the bacteria Agrobacterium tumefaciens or A. rhizogenes, or by direct methods like the gene gun or microinjection. Using plant viruses to insert genetic constructs into plants is also a possibility, but the technique is limited by the host range of the virus. For example, Cauliflower mosaic virus (CaMV) only infects cauliflower and related species. Another limitation of viral vectors is that the virus is not usually passed on to the progeny, so every plant has to be inoculated.

The majority of commercially released transgenic plants are currently limited to plants that have introduced resistance to insect pests and herbicides. Insect resistance is achieved through incorporation of a gene from Bacillus thuringiensis (Bt) that encodes a protein that is toxic to some insects. For example, the cotton bollworm, a common cotton pest, feeds on Bt cotton it will ingest the toxin and die. Herbicides usually work by binding to certain plant enzymes and inhibiting their action. The enzymes that the herbicide inhibits are known as the herbicide's "target site". Herbicide resistance can be engineered into crops by expressing a version of target site protein that is not inhibited by the herbicide. This is the method used to produce glyphosate resistant ("Roundup Ready") crop plants.

Genetic modification can further increase yields by increasing stress tolerance to a given environment. Stresses such as temperature variation, are signalled to the plant via a cascade of signalling molecules which will activate a transcription factor to regulate gene expression. Overexpression of particular genes involved in cold acclimation has been shown to produce more resistance to freezing, which is one common cause of yield loss

Genetic modification of plants that can produce pharmaceuticals (and industrial chemicals), sometimes called pharming, is a rather radical new area of plant breeding.

The debate surrounding genetically modified food during the 1990s peaked in 1999 in terms of media coverage and risk perception, and continues today – for example, "Germany has thrown its weight behind a growing European mutiny over genetically modified crops by banning the planting of a widely grown pest-resistant corn variety." The debate encompasses the ecological impact of genetically modified plants, the safety of genetically modified food and concepts used for safety evaluation like substantial equivalence. Such concerns are not new to plant breeding. Most countries have regulatory processes in place to help ensure that new crop varieties entering the marketplace are both safe and meet farmers' needs. Examples include variety registration, seed schemes, regulatory authorizations for GM plants, etc.

Breeding and the microbiome

Industrial breeding of plants has unintentionally altered how agricultural cultivars associate with their microbiome. In maize, for example, breeding has altered the nitrogen cycling taxa required to the rhizosphere, with more modern lines recruiting less nitrogen fixing taxa and more nitrifiers and denitrifiers. Microbiomes of breeding lines showed that hybrid plants share much of their bacterial community with their parents, such as Cucurbita seeds and apple shoot endophytes. In addition, the proportional contribution of the microbiome from parents to offspring corresponds to the amount of genetic material contributed by each parent during breeding and domestication.

Phenotyping and artificial intelligence

As of 2020 machine learning – and especially deep machine learning – has recently become more commonly used in phenotyping. Computer vision using ML has made great strides and is now being applied to leaf phenotyping and other phenotyping jobs typically performed by human eyes. Pound et al. 2017 and Singh et al. 2016 are especially salient examples of early successful application and demonstration of the general usability of the process across multiple target plant species. These methods will work even better with large, publicly available open data sets.

Speed breeding

Speed breeding is introduced by Watson et al. 2018. Classical (human performed) phenotyping during speed breeding is also possible, using a procedure developed by Richard et al. 2015. As of 2020 it is highly anticipated that SB and automated phenotyping will, combined, produce greatly improved outcomes – see § Phenotyping and artificial intelligence above.

Genomic selection (GS)

The NGS platform has substantially declined the time and cost required for sequencing and facilitated SNP discovery in model and non-model plants. This in turn has led to employing large-scale SNP markers in genomic selection approaches which aim at predicting genomic breeding values/GEBVs of genotypes in a given population. This method can increase the selection accuracy and decrease the time of each breeding cycle. It has been used in different crops such as maize, wheat, etc.

Participatory plant breeding

Participatory plant breeding (PPB) is when farmers are involved in a crop improvement programme with opportunities to make decisions and contribute to the research process at different stages. Participatory approaches to crop improvement can also be applied when plant biotechnologies are being used for crop improvement. Local agricultural systems and genetic diversity are strengthened by participatory programs, and outcomes are enhanced by farmers knowledge of the quality required and evaluation of the target environment.

A 2019 review of participatory plant breeding indicated that it had not gained widespread acceptance despite its record of successfully developing varieties with improved diversity and nutritional quality, as well as greater likelihood of these improved varieties being adopted by farmers. This review also found participatory plant breeding to have a better cost/benefit ratio than non-participatory approaches, and suggested incorporating participatory plant breeding with evolutionary plant breeding.

Evolutionary plant breeding

See also: Landrace § Plant_landrace_development

Evolutionary plant breeding describes practices which use mass populations with diverse genotypes grown under competitive natural selection. Survival in common crop cultivation environments is the predominant method of selection, rather than direct selection by growers and breeders. Individual plants that are favored under prevailing growing conditions, such as environment and inputs, contribute more seed to the next generation than less-adapted individuals. Evolutionary plant breeding has been successfully used by the Nepal National Gene Bank to preserve landrace diversity within Jumli Marshi rice while reducing its susceptibility to blast disease. These practices have also been used in Nepal with bean landraces.

In 1929, Harlan and Martini proposed a method of plant breeding with heterogeneous populations by pooling an equal number of F2 seeds obtained from 378 crosses among 28 geographically diverse barley cultivars. In 1938, Harlan and Martini demonstrated evolution by natural selection in mixed dynamic populations as a few varieties that became dominant in some locations almost disappeared in others; poorly-adapted varieties disappeared everywhere.

Evolutionary breeding populations have been used to establish self-regulating plant–pathogen systems. Examples include barley, where breeders were able to improve resistance to Rynchosporium secalis scald over 45 generations. An evolutionary breeding project grew F5 hybrid bulk soybean populations on soil infested by the soybean cyst nematode and was able to increase the proportion of resistant plants from 5% to 40%. The International Center for Agricultural Research in the Dry Areas (ICARDA) evolutionary plant breeding is combined with participatory plant breeding in order to allow farmers to choose which varieties suit their needs in their local environment.

An influential 1956 effort by Coit A. Suneson to codify this approach coined the term evolutionary plant breeding and concluded that 15 generations of natural selection are desirable to produce results that are competitive with conventional breeding. Evolutionary breeding allows working with much larger plant population sizes than conventional breeding. It has also been used in tandem with conventional practices in order to develop both heterogeneous and homogeneous crop lines for low input agricultural systems that have unpredictable stress conditions.

Evolutionary plant breeding has been delineated into four stages:

• Stage 1: Genetic diversity is created, for example by manual crosses of inbreeding species or mixing of cultivars in outcrossing species.
• Stage 2: Multiplication of seeds
• Stage 3: Seeds of each cross are then mixed to produce the first generation of the Composite Cross Population (CCP). The entire offspring is sown to grow and set seed. As the number of plants in the population increases, a proportion of the harvested seed is saved for sowing.
• Stage 4: The seed can be used for continued evolutionary plant breeding or as a starting point for a conventional breeding effort.

Issues and concerns

Breeding and food security

Issues facing plant breeding in the future include the lack of arable land, increasingly harsh cropping conditions and the need to maintain food security, which involves being able to provide the world population with sufficient nutrition. Crops need to be able to mature in multiple environments to allow worldwide access, which involves solving problems including drought tolerance. It has been suggested that global solutions are achievable through the process of plant breeding, with its ability to select specific genes allowing crops to perform at a level which yields the desired results. One issue facing agriculture is the loss of landraces and other local varieties which have diversity that may have useful genes for climate adaptation in the future.

Conventional breeding intentionally limits phenotype plasticity within genotypes and limits variability between genotypes. Uniformity does not allow crops to adapt to climate change and other biotic stresses and abiotic stresses.

Plant breeders rights

Plant breeders' rights is an important and controversial issue. Production of new varieties is dominated by commercial plant breeders, who seek to protect their work and collect royalties through national and international agreements based in intellectual property rights. The range of related issues is complex. In the simplest terms, critics of the increasingly restrictive regulations argue that, through a combination of technical and economic pressures, commercial breeders are reducing biodiversity and significantly constraining individuals (such as farmers) from developing and trading seed on a regional level. Efforts to strengthen breeders' rights, for example, by lengthening periods of variety protection, are ongoing.

Intellectual property legislation for plants often uses definitions that typically include genetic uniformity and unchanging appearance over generations. These legal definitions of stability contrast with traditional agronomic usage, which considers stability in terms of how consistent the yield or quality of a crop remains across locations and over time.

As of 2020, regulations in Nepal only allow uniform varieties to be registered or released. Evolutionary plant populations and many landraces are polymorphic and do not meet these standards.

Environmental stressors

Uniform and genetically stable cultivars can be inadequate for dealing with environmental fluctuations and novel stress factors. Plant breeders have focused on identifying crops which will ensure crops perform under these conditions; a way to achieve this is finding strains of the crop that is resistance to drought conditions with low nitrogen. It is evident from this that plant breeding is vital for future agriculture to survive as it enables farmers to produce stress resistant crops hence improving food security. In countries that experience harsh winters such as Iceland, Germany and further east in Europe, plant breeders are involved in breeding for tolerance to frost, continuous snow-cover, frost-drought (desiccation from wind and solar radiation under frost) and high moisture levels in soil in winter.

Long-term process

Breeding is not a quick process, which is especially important when breeding to ameliorate a disease. The average time from human recognition of a new fungal disease threat to the release of a resistant crop for that pathogen is at least twelve years.

Maintaining specific conditions

When new plant breeds or cultivars are bred, they must be maintained and propagated. Some plants are propagated by asexual means while others are propagated by seeds. Seed propagated cultivars require specific control over seed source and production procedures to maintain the integrity of the plant breeds results. Isolation is necessary to prevent cross contamination with related plants or the mixing of seeds after harvesting. Isolation is normally accomplished by planting distance but in certain crops, plants are enclosed in greenhouses or cages (most commonly used when producing F1 hybrids).

Nutritional value

Modern plant breeding, whether classical or through genetic engineering, comes with issues of concern, particularly with regard to food crops. The question of whether breeding can have a negative effect on nutritional value is central in this respect. Although relatively little direct research in this area has been done, there are scientific indications that, by favoring certain aspects of a plant's development, other aspects may be retarded. A study published in the Journal of the American College of Nutrition in 2004, entitled Changes in USDA Food Composition Data for 43 Garden Crops, 1950 to 1999, compared nutritional analysis of vegetables done in 1950 and in 1999, and found substantial decreases in six of 13 nutrients measured, including 6% of protein and 38% of riboflavin. Reductions in calcium, phosphorus, iron and ascorbic acid were also found. The study, conducted at the Biochemical Institute, University of Texas at Austin, concluded in summary: "We suggest that any real declines are generally most easily explained by changes in cultivated varieties between 1950 and 1999, in which there may be trade-offs between yield and nutrient content."

Plant breeding can contribute to global food security as it is a cost-effective tool for increasing nutritional value of forage and crops. Improvements in nutritional value for forage crops from the use of analytical chemistry and rumen fermentation technology have been recorded since 1960; this science and technology gave breeders the ability to screen thousands of samples within a small amount of time, meaning breeders could identify a high performing hybrid quicker. The genetic improvement was mainly in vitro dry matter digestibility (IVDMD) resulting in 0.7-2.5% increase, at just 1% increase in IVDMD a single Bos Taurus also known as beef cattle reported 3.2% increase in daily gains. This improvement indicates plant breeding is an essential tool in gearing future agriculture to perform at a more advanced level. 

Yield

With an increasing population, the production of food needs to increase with it. It is estimated that a 70% increase in food production is needed by 2050 in order to meet the Declaration of the World Summit on Food Security. But with the degradation of agricultural land, simply planting more crops is no longer a viable option. New varieties of plants can in some cases be developed through plant breeding that generate an increase of yield without relying on an increase in land area. An example of this can be seen in Asia, where food production per capita has increased twofold. This has been achieved through not only the use of fertilisers, but through the use of better crops that have been specifically designed for the area.

Role of plant breeding in organic agriculture

Some critics of organic agriculture claim it is too low-yielding to be a viable alternative to conventional agriculture in situations when that poor performance may be the result in part of growing poorly-adapted varieties. It is estimated that over 95% of organic agriculture is based on conventionally adapted varieties, even though the production environments found in organic vs. conventional farming systems are vastly different due to their distinctive management practices. Most notably, organic farmers have fewer inputs available than conventional growers to control their production environments. Breeding varieties specifically adapted to the unique conditions of organic agriculture is critical for this sector to realize its full potential. This requires selection for traits such as:

• Water use efficiency
• Nutrient use efficiency (particularly nitrogen and phosphorus)
• Weed competitiveness
• Tolerance of mechanical weed control
• Pest/disease resistance
• Early maturity (as a mechanism for avoidance of particular stresses)
• Abiotic stress tolerance (i.e. drought, salinity, etc...)

Currently, few breeding programs are directed at organic agriculture and until recently those that did address this sector have generally relied on indirect selection (i.e. selection in conventional environments for traits considered important for organic agriculture). However, because the difference between organic and conventional environments is large, a given genotype may perform very differently in each environment due to an interaction between genes and the environment (see gene–environment interaction). If this interaction is severe enough, an important trait required for the organic environment may not be revealed in the conventional environment, which can result in the selection of poorly adapted individuals. To ensure the most adapted varieties are identified, advocates of organic breeding now promote the use of direct selection (i.e. selection in the target environment) for many agronomic traits.

There are many classical and modern breeding techniques that can be utilized for crop improvement in organic agriculture despite the ban on genetically modified organisms. For instance, controlled crosses between individuals allow desirable genetic variation to be recombined and transferred to seed progeny via natural processes. Marker assisted selection can also be employed as a diagnostics tool to facilitate selection of progeny who possess the desired trait(s), greatly speeding up the breeding process. This technique has proven particularly useful for the introgression of resistance genes into new backgrounds, as well as the efficient selection of many resistance genes pyramided into a single individual. Molecular markers are not currently available for many important traits, especially complex ones controlled by many genes.

Nitrogen assimilation

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Nitrogen_assimilation

Nitrogen assimilation is the formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds present in the environment. Organisms like plants, fungi and certain bacteria that can fix nitrogen gas (N₂) depend on the ability to assimilate nitrate or ammonia for their needs. Other organisms, like animals, depend entirely on organic nitrogen from their food.

Nitrogen assimilation in plants

Plants absorb nitrogen from the soil in the form of nitrate (NO₃⁻) and ammonium (NH₄⁺). In aerobic soils where nitrification can occur, nitrate is usually the predominant form of available nitrogen that is absorbed. However this is not always the case as ammonia can predominate in grasslands and in flooded, anaerobic soils like rice paddies. Plant roots themselves can affect the abundance of various forms of nitrogen by changing the pH and secreting organic compounds or oxygen. This influences microbial activities like the inter-conversion of various nitrogen species, the release of ammonia from organic matter in the soil and the fixation of nitrogen by non-nodule-forming bacteria.

Ammonium ions are absorbed by the plant via ammonia transporters. Nitrate is taken up by several nitrate transporters that use a proton gradient to power the transport. Nitrogen is transported from the root to the shoot via the xylem in the form of nitrate, dissolved ammonia and amino acids. Usually (but not always) most of the nitrate reduction is carried out in the shoots while the roots reduce only a small fraction of the absorbed nitrate to ammonia. Ammonia (both absorbed and synthesized) is incorporated into amino acids via the glutamine synthetase-glutamate synthase (GS-GOGAT) pathway. While nearly all the ammonia in the root is usually incorporated into amino acids at the root itself, plants may transport significant amounts of ammonium ions in the xylem to be fixed in the shoots. This may help avoid the transport of organic compounds down to the roots just to carry the nitrogen back as amino acids.

Nitrate reduction is carried out in two steps. Nitrate is first reduced to nitrite (NO₂⁻) in the cytosol by nitrate reductase using NADH or NADPH. Nitrite is then reduced to ammonia in the chloroplasts (plastids in roots) by a ferredoxin dependent nitrite reductase. In photosynthesizing tissues, it uses an isoform of ferredoxin (Fd1) that is reduced by PSI while in the root it uses a form of ferredoxin (Fd3) that has a less negative midpoint potential and can be reduced easily by NADPH. In non photosynthesizing tissues, NADPH is generated by glycolysis and the pentose phosphate pathway.

In the chloroplasts, glutamine synthetase incorporates this ammonia as the amide group of glutamine using glutamate as a substrate. Glutamate synthase (Fd-GOGAT and NADH-GOGAT) transfer the amide group onto a 2-oxoglutarate molecule producing two glutamates. Further transaminations are carried out make other amino acids (most commonly asparagine) from glutamine. While the enzyme glutamate dehydrogenase (GDH) does not play a direct role in the assimilation, it protects the mitochondrial functions during periods of high nitrogen metabolism and takes part in nitrogen remobilization.

pH and Ionic balance during nitrogen assimilation

Different plants use different pathways to different levels. Tomatoes take in a lot of K⁺ and accumulate salts in their vacuoles, castor reduces nitrate in the roots to a large extent and excretes the resulting alkali. Soy bean plants moves a large amount of malate to the roots where they convert it to alkali while the potassium is recirculated.

Every nitrate ion reduced to ammonia produces one OH⁻ ion. To maintain a pH balance, the plant must either excrete it into the surrounding medium or neutralize it with organic acids. This results in the medium around the plants roots becoming alkaline when they take up nitrate.

To maintain ionic balance, every NO₃⁻ taken into the root must be accompanied by either the uptake of a cation or the excretion of an anion. Plants like tomatoes take up metal ions like K⁺, Na⁺, Ca²⁺ and Mg²⁺ to exactly match every nitrate taken up and store these as the salts of organic acids like malate and oxalate. Other plants like the soybean balance most of their NO₃⁻ intake with the excretion of OH⁻ or HCO₃⁻.

Plants that reduce nitrates in the shoots and excrete alkali from their roots need to transport the alkali in an inert form from the shoots to the roots. To achieve this they synthesize malic acid in the leaves from neutral precursors like carbohydrates. The potassium ions brought to the leaves along with the nitrate in the xylem are then sent along with the malate to the roots via the phloem. In the roots, the malate is consumed. When malate is converted back to malic acid prior to use, an OH⁻ is released and excreted. (RCOO⁻ + H₂O -> RCOOH +OH⁻) The potassium ions are then recirculated up the xylem with fresh nitrate. Thus the plants avoid having to absorb and store excess salts and also transport the OH⁻.

Plants like castor reduce a lot of nitrate in the root itself, and excrete the resulting base. Some of the base produced in the shoots is transported to the roots as salts of organic acids while a small amount of the carboxylates are just stored in the shoot itself.

Nitrogen use efficiency

Nitrogen use efficiency (NUE) is the proportion of nitrogen present that a plant absorbs and uses. Improving nitrogen use efficiency and thus fertilizer efficiency is important to make agriculture more sustainable, by reducing pollution (fertilizer runoff) and production cost and increasing yield. Worldwide, crops generally have less than 50% NUE. Better fertilizers, improved crop management, selective breeding, and genetic engineering can increase NUE.

Nitrogen use efficiency can be measured at various levels: the crop plant, the soil, by fertilizer input, by ecosystem productivity, etc. At the level of photosynthesis in leaves, it is termed photosynthetic nitrogen use efficiency (PNUE).

Agricultural biotechnology

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Agricultural_biotechnology 

Agricultural biotechnology, also known as agritech, is an area of agricultural science involving the use of scientific tools and techniques, including genetic engineering, molecular markers, molecular diagnostics, vaccines, and tissue culture, to modify living organisms: plants, animals, and microorganisms. Crop biotechnology is one aspect of agricultural biotechnology which has been greatly developed upon in recent times. Desired trait are exported from a particular species of Crop to an entirely different species. These transgene crops possess desirable characteristics in terms of flavor, color of flowers, growth rate, size of harvested products and resistance to diseases and pests.

History

Farmers have manipulated plants and animals through selective breeding for decades of thousands of years in order to create desired traits. In the 20th century, a surge in technology resulted in an increase in agricultural biotechnology through the selection of traits like the increased yield, pest resistance, drought resistance, and herbicide resistance. The first food product produced through biotechnology was sold in 1990, and by 2003, 7 million farmers were utilizing biotech crops. More than 85% of these farmers were located in developing countries.

Crop modification techniques

Traditional breeding

Traditional crossbreeding has been used for centuries to improve crop quality and quantity. Crossbreeding mates two sexually compatible species to create a new and special variety with the desired traits of the parents. For example, the honeycrisp apple exhibits a specific texture and flavor due to the crossbreeding of its parents. In traditional practices, pollen from one plant is placed on the female part of another, which leads to a hybrid that contains genetic information from both parent plants. Plant breeders select the plants with the traits they're looking to pass on and continue to breed those plants. Note that crossbreeding can only be utilized within the same or closely related species.

Mutagenesis

Mutations can occur randomly in the DNA of any organism. In order to create variety within crops, scientists can randomly induce mutations within plants. Mutagenesis uses radioactivity to induce random mutations in the hopes of stumbling upon the desired trait. Scientists can use mutating chemicals such as ethyl methanesulfonate, or radioactivity to create random mutations within the DNA. Atomic gardens are used to mutate crops. A radioactive core is located in the center of a circular garden and raised out of the ground to radiate the surrounding crops, generating mutations within a certain radius. Mutagenesis through radiation was the process used to produce ruby red grapefruits.

Polyploidy

Polyploidy can be induced to modify the number of chromosomes in a crop in order to influence its fertility or size. Usually, organisms have two sets of chromosomes, otherwise known as a diploidy. However, either naturally or through the use of chemicals, that number of chromosomes can change, resulting in fertility changes or size modification within the crop. Seedless watermelons are created in this manner; a 4-set chromosome watermelon is crossed with a 2-set chromosome watermelon to create a sterile (seedless) watermelon with three sets of chromosomes.

Protoplast fusion

Protoplast fusion is the joining of cells or cell components to transfer traits between species. For example, the trait of male sterility is transferred from radishes to red cabbages by protoplast fusion. This male sterility helps plant breeders make hybrid crops.

RNA interference

RNA interference (RNAIi) is the process in which a cell's RNA to protein mechanism is turned down or off in order to suppress genes. This method of genetic modification works by interfering with messenger RNA to stop the synthesis of proteins, effectively silencing a gene.

Transgenics

Transgenics involves the insertion of one piece of DNA into another organism's DNA in order to introduce new genes into the original organism. This addition of genes into an organism's genetic material creates a new variety with desired traits. The DNA must be prepared and packaged in a test tube and then inserted into the new organism. New genetic information can be inserted with gene guns/biolistics. An example of a gene gun transgenic is the rainbow papaya, which is modified with a gene that gives it resistance to the papaya ringspot virus.

Genome editing

Genome editing is the use of an enzyme system to modify the DNA directly within the cell. Genome editing is used to develop herbicide resistant canola to help farmers control weeds.

Improved nutritional content

Agricultural biotechnology has been used to improve the nutritional content of a variety of crops in an effort to meet the needs of an increasing population. Genetic engineering can produce crops with a higher concentration of vitamins. For example, golden rice contains three genes that allow plants to produce compounds that are converted to vitamin A in the human body. This nutritionally improved rice is designed to combat the world's leading cause of blindness—vitamin A deficiency. Similarly, the Banana 21 project has worked to improve the nutrition in bananas to combat micronutrient deficiencies in Uganda. By genetically modifying bananas to contain vitamin A and iron, Banana 21 has helped foster a solution to micronutrient deficiencies through the vessel of a staple food and major starch source in Africa. Additionally, crops can be engineered to reduce toxicity or to produce varieties with removed allergens.

Genes and traits of interest for crops

Agronomic traits

Insect resistance

One highly sought after trait is insect resistance. This trait increases a crop's resistance to pests and allows for a higher yield. An example of this trait are crops that are genetically engineered to make insecticidal proteins originally discovered in (Bacillus thuringiensis). Bacillus thuringiensis is a bacterium that produces insect repelling proteins that are non-harmful to humans. The genes responsible for this insect resistance have been isolated and introduced into many crops. Bt corn and cotton are now commonplace, and cowpeas, sunflower, soybeans, tomatoes, tobacco, walnut, sugar cane, and rice are all being studied in relation to Bt.

Herbicide tolerance

Weeds have proven to be an issue for farmers for thousands of years; they compete for soil nutrients, water, and sunlight and prove deadly to crops. Biotechnology has offered a solution in the form of herbicide tolerance. Chemical herbicides are sprayed directly on plants in order to kill weeds and therefore competition, and herbicide resistant crops have to the opportunity to flourish.

Disease resistance

Often, crops are afflicted by disease spread through insects (like aphids). Spreading disease among crop plants is incredibly difficult to control and was previously only managed by completely removing the affected crop. The field of agricultural biotechnology offers a solution through genetically engineering virus resistance. Developing GE disease-resistant crops now include cassava, maize, and sweet potato.

Temperature tolerance

Agricultural biotechnology can also provide a solution for plants in extreme temperature conditions. In order to maximize yield and prevent crop death, genes can be engineered that help to regulate cold and heat tolerance. For example, tobacco plants have been genetically modified to be more tolerant to hot and cold conditions, with genes originally found in Carica papaya. Other traits include water use efficiency, nitrogen use efficiency and salt tolerance.

Quality traits

Quality traits include increased nutritional or dietary value, improved food processing and storage, or the elimination of toxins and allergens in crop plants.

Common GMO crops

Currently, only a small number of genetically modified crops are available for purchase and consumption in the United States. The USDA has approved soybeans, corn, canola, sugar beets, papaya, squash, alfalfa, cotton, apples, and potatoes. GMO apples (arctic apples) are non-browning apples and eliminate the need for anti-browning treatments, reduce food waste, and bring out flavor. The production of Bt cotton has skyrocketed in India, with 10 million hectares planted for the first time in 2011, resulting in a 50% insecticide application reduction. In 2014, Indian and Chinese farmers planted more than 15 million hectares of Bt cotton.

Safety testing and government regulations

Agricultural biotechnology regulation in the US falls under three main government agencies: The Department of Agriculture (USDA), the Environmental Protection Agency (EPA), and the Food and Drug Administration (FDA). The USDA must approve the release of any new GMOs, EPA controls the regulation of insecticide, and the FDA evaluates the safety of a particular crop sent to market. On average, it takes nearly 13 years and $130 million of research and development for a genetically modified organism to come to market. The regulation process takes up to 8 years in the United States. The safety of GMOs has become a topic of debate worldwide, but scientific articles are being conducted to test the safety of consuming GMOs in addition to the FDA's work. In one such article, it was concluded that Bt rice did not adversely affect digestion and did not induce horizontal gene transfer.

Climate change education

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Climate_change_education

A UNESCO diagram visualising a "whole school approach" to climate change

Climate change education (CCE) is education that aims to address and develop effective responses to climate change. It helps learners understand the causes and consequences of climate change, prepares them to live with the impacts of climate change and empowers learners to take appropriate actions to adopt more sustainable lifestyles. Climate change and climate change education are global challenges that can be anchored in the curriculum in order to provide local learning and widen up mindset shits on how climate change can be mitigated. In such as case CCE is more than climate change literacy but understanding ways of dealing with climate.

CCE helps policymakers understand the urgency and importance of putting mechanisms into place to combat climate change on a national and global scale. Communities learn about how climate change will affect them, what they can do to protect themselves from negative consequences, and how they can reduce their own carbon footprint. In particular, CCE helps increase the resilience of already vulnerable communities who are the most likely to be adversely affected by climate change. CCE is rooted in Education for sustainable development (ESD).

UNESCO Climate Change Education for Sustainable Development programme

Established in 2010, the UNESCO Climate Change Education for Sustainable Development programme (CCESD) aims to help people understand climate change by expanding CCE activities in nonformal education through the media, networking and partnerships. With the help of organizations and individuals, UNESCO is able to host the World Higher Education Conference (in Barcelona 2022). It is grounded in the holistic approach of Education for Sustainable Development (ESD) which incorporates key sustainable development issues such as climate change, disaster risk reduction and others into education, in a way that addresses the interdependence of environmental sustainability, economic viability and social justice. It promotes participatory teaching and learning methods that motivate and empower learners to change their behaviour and take action for sustainable development. The programme seeks to help people understand the impact of global warming today and increase 'climate literacy', especially among young people, and aims to make education a more central part of the international response to climate change. UNESCO works with national governments to integrate CCE into national curricula and to develop innovative teaching and learning approaches for doing so.

Selected country profiles regarding CCE and ESD

Australia

Australia has been at the forefront of education for sustainability, adopting in 2000 a national plan entitled Environmental Education for a Sustainable Future. A number of initiatives and bodies were created to implement the national plan, including the Australian Sustainable Schools Initiative and Australian Research Institute for Environment and Sustainability. These provided a strong foundation for Australia's strategy, launched in 2006, to respond to the UN Decade of Education for Sustainable Development. The strategy set out the goal to mainstream sustainability through a holistic approach that engages the community through education and lifelong learning. Whereas climate change was referred to as one of a number of environmental concerns in the first national plan, a new plan launched in 2009, entitled Living Sustainably: the Australian Government's National Action Plan for Education for Sustainability, had a greater focus on climate change and its impacts on other natural resources within a wider global context. The new plan incorporated climate change within education for sustainability, rather than establishing a new and potentially competing field of Climate Change Education. Australia introduced its first-ever national curriculum in 2014, including sustainability as one of three cross-curriculum subjects.

Since 2009, Climate Change Education has been most evident in the VET sector. COAG endorsed the Green Skills Agreement in 2009, and the Ministerial Council for Vocational and Technical Education published the National VET Sector Sustainability Policy and Action Plan (2009-2012). These initiatives aimed to provide workers with the skills needed to transition to a low-carbon economy and VET teachers with suitable training packages to promote education for sustainability.

China

China introduced environmental education in the late 1970s as a result of increased attention to sustainable development and the need to protect the environment. Following the United Nations Conference on Environment and Development (Rio de Janeiro, 1992), environmental education moved towards environment, population and development, and finally education for sustainable development.

The Chinese government has produced a number of policy documents identifying environmental education and ESD as key to quality education. In 2003, the Ministry of Education issued the first guiding policy - the Guidelines for Implementing Environmental Education in Elementary and Secondary School - on environmental education in China. ESD was formally incorporated into the national education policy in 2010 in The National Education Outline 2010-2020, and further integrated in some local education policies. National climate change policies and plans in China refer to education but do not specifically address CCE. This has resulted in limited institutional support to date. There is no national ESD or CCE action plan or official policy to inform its implementation.

In China, ESD mainly refers to providing individuals with the scientific knowledge, learning capacity, values and lifestyle choices to meet the country's sustainable development objectives. CCE is most commonly implemented as a component of ESD. A number of educational approaches have been adopted to facilitate the implementation of ESD. These include integrating ESD values into school philosophy, curriculum development, capacity-building of teachers and educators, ESD pedagogical approaches and ESD and CCE thematic activities.

ESD is a component of compulsory education, but is limited in higher education, VET and adult education. The Ministry of Education has recently issued a guidance document that identified the VET sector in particular as needing to be reformed to meet the sustainable development objectives of the Chinese economy.

Denmark

Denmark and its neighbouring countries began working together in the 1990s to formulate a policy for ESD. While Denmark signed the United Nations Economic Commission for Europe (UNECE) declaration on ESD in 2005, it did not adopt a strategy until 2009, just before the half-way point of the DESD. The Ministry of Education, which was made responsible for the DESD, organised a consultation process on how to promote ESD before adopting its strategy in 2009.

The UN Climate Summit (COP15) held in Denmark in December 2009 provided the impetus to develop of a number of national ESD policy initiatives. A national strategy on ESD was developed with a substantial climate change component. The aim of the strategy is to make citizens more responsible for their actions by improving their scientific knowledge. The ESD strategy notes that climate change should not be the sole focus of ESD, though the concrete initiatives that are part of the strategy mostly support the CCE projects and activities that were part of COP15 preparations.

A new national school curriculum adopted in 2009 included elements of ESD and CCE. The concept of sustainability was embedded in the goals describing the interrelationships between nature and society. CCE is mostly approached as teaching climate science, but it was also included in subjects such as geography and social studies, where the interrelationships between human behaviour, consumption and climate are examined.

There has been no explicit policy change in the TVET sector to upgrade skills to respond to climate change and environmental issues. However, it is important to note that the Danish TVET sector had previously reflected skills related to ecological modernisation in areas such as energy generation, waste management and agriculture. While the new government identified the economic and environmental climate change crises as important, education is only referred to in relation to the economic crisis. There is no mention of climate change or sustainability with regard to education, and the platform documentation on 'green transition' does not mention education. Overall, no policy strategy has been set to promote ESD, CCE, or the 'greening' of TVET as part of the government's sustainable development and climate change policies. Government initiatives support NGO-led projects to raise community awareness of climate change. A national network on ESD was established with funding through to 2013.

Dominican Republic

The Dominican Republic has taken a lead role in promoting ESD. Environmental education was made mandatory for all schools in 1998 and this has since evolved into ESD. In 2000, the General Law of Environment and Natural Resources changed the way environmental education was taught, moving from a subject matter to a cross-cutting and interdisciplinary theme. Risk management is also an important aspect of MINERD's strategic plan, and has been integrated into the school curriculum as a cross-cutting subject. In 2004, the Environmental Education Strategy for Sustainable Development was adopted, which fosters formal and non-formal ESD. It is based on constructivism and uses a variety of pedagogical techniques that promote participatory learning.

The Ten-year 2008-2018 Education Plan (PDE) addresses the issue of quality education, including sustainable development and a culture of peace. It also established a process for periodic review of the curriculum. Climate change is also being introduced into the curriculum. The National Teacher Training Institute (INAFOCAM) and the Salomé Ureña Higher Institute for Teacher Training (ISFODOSU) provide support for environmental education through teacher training and curriculum support. The Ten-year 2008-2018 Higher Education Plan (PDES) includes environmental issues in the curricula and establishes a research programme to promote sustainable development.

The Dominican Republic has been involved in a number of ESD and CCE initiatives that have helped build local capacity, including:

• formal, non-formal and informal projects on ESD led by governmental agencies, civil society organizations, young leaders and local communities;
• UN: CC Learn Project, which supports the design and implementation of results-oriented and sustainable learning to address climate change (see the detailed case study in this Report);
• National Strategy to Strengthen Human Resource Capacities to Advance Green, Low Emission and Climate Resilient Development (ENDVBERC);
• teacher training supported by the UN: CC Learn-UNITAR, and the UNESCO-CCESD pilot programme.

UK

In the United Kingdom, the Teach the Future campaign aims to rapidly repurpose the education system around the climate emergency and ecological crisis; they are cohosted by the UK Student Climate Network and SOS-UK and are in the process of devolving their campaign to Scotland and Northern Ireland from England.

They have 3 asks of the Government

• A government commissioned review into how the English formal education system is preparing students for the climate emergency and ecological crisis
• The inclusion of the climate emergency and ecological crisis in English teaching standards and training
• The enactment of an English Climate Emergency Education Act - the first student written bill in history

England

Environmental and development education have been present in England since the 1970s, when civil society organizations took the lead. From the late 1990s, the UK government promoted sustainable development and ESD at the local, regional and national levels. However, while a number of strategic government reports addressed CCE, government policy has focused less on ESD since 2010.

The 2008 report Brighter Futures – Greener Lives: Sustainable Development Action Plan 2008-2010 outlined a number of specific initiatives related to Climate Change Education using an ESD approach. This included empowering youth with the skills, knowledge and freedom to voice their opinions and make a difference. The same year, CCE was introduced into the Key Stage 3 (11 to 14 year-olds) geography curriculum.

The report Education for Sustainable Development in the UK 2010 noted that there were signs of substantial progress in embedding ESD-related policies and developing practices in the UK across a wide range of sectors in 2008 and 2009. For example, documents in 2009 highlighted the 'Sustainable Schools' project that aims to empower youth to cope with the future challenges facing the planet. The aim is for all schools to be 'Sustainable Schools' by 2020.

Scotland

The Scottish Government commissioned a climate change TV advert, possibly as part of public awareness program.

Republic of Korea

The Republic of Korea has a number of policies and initiatives supporting environmental education. In 2008, the Environmental Education Promotion Act encouraged the development of environmental education. It aimed to raise national environmental awareness, to encourage people to develop research and inquiry skills, and to put what they learn into action.

The Ministry of Environment, in its 2011-2015 Environmental Education Master Plan, proposed a policy agenda for environmental education to be implemented through formal education, social environmental education and educational infrastructure approaches. The various approaches in the formal education area include:

• 'Environment and Green Growth' as an elective subject in middle and high school curricula, and classes in elementary school designed to integrate environmental education;
• the establishment of the Natural Environmental Studies Institute that offers interactive youth programmes for environmental studies;
• Environment Model Schools, designed to demonstrate best-practice;
• 'Low Carbon Challenge' involving ten universities;
• in-service training for teachers to upskill, specializing in environmental education.

Vietnam

The development of ESD in Vietnam took place in the most recent decades. The National Council of Sustainable Development was formed in 2006 to acknowledge the United Nations Decade of Education for Sustainable Development (DESD). A committee consisting of high-ranking leaders such as government leaders and ministers were appointed to develop an education for sustainability guideline.

The Ministry for Education and Training (MOET) played an important role to push forward establishment goals for ESD and CCE. Furthermore, they were also able to recognize the climate change impacts overall in Vietnam such as increase in average temperature and sea rise level. From 1951-2000, Vietnam's global average temperature increased about 0.5-0.7 Celsius, and sea level had risen about 20 cm. These two factors had put a hold on the growing socioeconomic achievements; therefore, MOET acted on the development education aspects to mitigate climate change in the future. The first key steps MOET promoted toward ESD and CCE were the National Action Plan of Education for Sustainable Development of Viet Nam in 2010 and the Action Plan for Response to Climate Change of the Education Sector for the period of 2011-2015.

Action Plan of Education for Sustainable Development

In 2016, Vietnam, Costa Rica, and Kenya started their partnership with UNESCO to establish high standard ESD policies at a regional and global level. Through UNESCO, there were four main projects that the countries can get involved in different socioeconomic levels such as Advancing ESD policy development, A whole-institution approach to climate change through the UNESCO Associated Schools Network (ASPnet), Sustainability starts with teachers, Empower youth ESD leaders as change agents, and Community for ESD.

Climate Change Education

  In 2009, MOET was able to develop and implement environmental education (EE) and CCE education into formal education curriculum. This gained approval from ESD standpoints, however it was still not considered to count towards all ESD approaches. Furthermore, one of the main challenges MOET was facing during this time was an increase of materials on top the regular curriculum, resulted in overloading students with knowledge.

United States of America

Since the year 2013, over 20 states and the District of Columbia have adopted the Next Generation Science Standards which encourages "climate literacy" in order to better educate students of Earth's current climate crisis with updated scientific information around climate change. According to the Yale Program on Climate Change Communication, Americans in all 50 states support the education of climate change to children in schools.

In 2020, the New Jersey State Board of Education adopted new learning standards which integrate climate change across all content areas; the standards came into effect with the 2022-23 school year, making New Jersey the first state to do so.