CROP BIOTECH UPDATE
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A weekly summary of world developments in agri-biotech for developing countries, produced by the Global Knowledge Center on Crop Biotechnology, International Service for the Acquisition of Agri-biotech Applications SEAsiaCenter (ISAAA)
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January 10, 2018
In This Week’s Issue:
News
Global
• Team of International Scientists Unlocks Peanut's Genetic Code
Africa
• IITA Begins Confined Field Trials of Transgenic Cassava
Americas
• Global Research Team Identifies Pathogen Gene that Wheat Plants Detect to ‘Switch On' Resistance
• Salk Scientists Discover Unusual Immune Response of Plants to Bacterial Infection
• Researchers Find Genetic Mechanism that Could Enhance Yield of Cereal Crops
Asia and the Pacific
• FSANZ Releases Approval Report for Food Derived from Golden Rice
Europe
• European Commission Authorizes Six GM Crops for Food and Feed
Research
• TaHDZipI-5 Involved in Drought and Frost Tolerance in Wheat
• Plastocyanin Gene from Seepweed Improves Oxidative Stress Tolerance in Arabidopsis
• Overexpression of PaFKBP12 in Arabidopsis Enhances Tolerance to Multiple Stresses
New Breeding Technologies
• Scientists Use CRISPR-Cas9 Technology to Improve Drought and Salt Tolerance in Rice
• Genome Editing of CLAVATA Genes in Canola Regulates Multilocular Silique Development
Beyond Crop Biotech
• Researchers Find Gene Involved in Arsenic Resistance in Poplar
Document Reminders
• ISAAA Blog: How Filipino News Writers Define Biotechnology
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NEWS
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Global
TEAM OF INTERNATIONAL SCIENTISTS UNLOCKS PEANUT'S GENETIC CODE
A team of international scientists, including researchers from University of Georgia and U.S. Department of Agriculture have successfully mapped peanut's genetic code. The findings of the five-year study provide relevant data to help other scientists around the world decode some of the genetic potential of the peanut plant.
"Mapping the genetic code of the peanut proved to be an especially difficult task, but the final product is one of the best ever generated," said Steve Brown, executive director of The Peanut Foundation (IPF). "We now have a map that will help breeders incorporate desirable traits that benefit growers, processors, and most importantly, the consumers that enjoy delicious and nutritious peanut products all over the world."
The Peanut Genome Consortium includes scientists from the U.S., China, Japan, Brazil, Argentina, Australia, India, Israel, and several countries in Africa. The findings will enable scientists to search for beneficial genes in cultivated and wild peanut varieties that can be harnessed to develop new peanut varieties. Traits can be improved to achieve greater yields, lower production costs, lower losses to disease, better flavor, improved processing traits, nutrition, and safety, as well as virtually anything that is genetically determined by the peanut plant.
Read the original article from Southeast Farm Press and the full report from The Peanut Foundation website.
The International Institute of Tropical Agriculture (IITA), in collaboration with ETH Zurich Plant Biotechnology Lab has started the confined field trials of transgenic cassava. The research aims to reduce starch breakdown in storage roots of cassava after pruning the shoots, before the crop is harvested. It is also a fact-gathering process to gain fundamental knowledge about starch metabolism in the storage root and about cassava as a crop.
Cassava is an important food crop in sub-Saharan Africa as well as other tropical and subtropical regions, but cassava farmers face high level of postharvest loss caused by rapid deterioration of the starch-rich roots which occurs naturally after harvesting. The project aims to address this through cassava plant cultivar 60444 generated in ETH Zurich using RNAi to reduce starch breakdown in the root after pruning of the shoots.
The CFT permit was issued by the National Biosafety Management Agency in accordance with the National Biosafety Agency Act 2015, for the period September 22, 2017 to December 31, 2018. IITA adheres strictly to national and international biosafety standards and will ensure that these are enforced during the trials, which will be carried out within the IITA campus in Ibadan, Nigeria. The cassava plants from the confined field trial are not destined for the market nor for commercial development, and therefore will not be consumed. And according to national regulations, all plants will be destroyed within the CFT site after analysis.
For more details, read the IITA News.
A team of researchers from the University of Sydney, Commonwealth Scientific and Industrial Research Organization (CSIRO) in Australia, Rothamsted Research in the United Kingdom, and the University of Minnesota and U.S. Department of Agriculture in the United States has discovered the first rust virulence molecule that wheat plants detect to ‘switch on' built-in resistance and stave off the disease.
Stem rust is the most dangerous pathogen of wheat, caused by the fungus Puccinia graminis f. sp. tritici (Pgt). Ug99, a particularly destructive form of Pgt, has recently received much attention because of its spread across Africa and the Middle East. The findings by this group of scientists published in Science reveal how the immune system in plants resistant to this disease directly recognizes a specific fungal protein to subsequently "turn on" resistance and fend off the pathogen.
Through this research, it will be possible to do DNA testing to identify whether a rust in a wheat crop anywhere in the world can overcome a rust-resistance gene, called Sr50. "Now that we've identified how stem rust strains are able to overcome Sr50 resistance – by mutation of a gene we've identified called AvrSr50 – this information can be used to help prioritize resistance genes for deployment," said University of Minnesota Plant Pathology Adjunct Professor Peter Dodds from CSIRO.
For more details about this research, read the news release from the University of Minnesota.
Scientists from Salk Institute for Biological Sciences reported an unusual plat immune response to bacterial infection. The result of their study is published in Nature Communications.
"There are a lot of losses in crop yields due to bacteria that kill plants…With this work, we set out to understand the underlying mechanism of how resistance works, and to see how general it is," said Joanne Chory, senior author of the study and a 2018 recipient of the Breakthrough Prize in Life Sciences. The research team studied a protein (SOBER1) in Arabidopsis thaliana, which was previously reported to impede the plant's immune response to a bacterial protein (AvrBsT). The researchers perceived that studying immune suppression may lead to more information about infection resistance.
They studied the amino acid sequence of SOBER1 and found that it can be classified as part of a vast protein superfamily of alpha/beta hydrolases. It was very similar to a cancer-pathway-related human enzyme. Further tests suggested that SOBER1 is a deacetylase, removing acetyl groups added by bacterial proteins. Without the acetyl groups tagging proteins, the plant didn't recognize them as foreign and thus didn't mount a cell-killing immune response. The researchers were surprised that SOBER's function is to keep infected tissue alive, putting the plant at risk. Chory said that they are just beginning to understand such mechanisms and they think that there are conditions where the actions of SOBER1 is helpful for the plant.
Further tests showed that the activity and function of SOBER1 are not restricted to Arabidopsis, but also exists in oilseed rape demonstrating that the findings of Chory's lab could be applied to agricultural crops and biofuel resources.
Read the news release from Salk for more details.
A research team from the Donald Danforth Plant Science Center led by Andrea Eveland has identified a genetic mechanism that could increase the yields of cereal crops. The team performed the research in Setaria viridis, a grass that is closely related to economically important cereal crops and bioenergy feed stocks such as maize, sorghum, switchgrass, and sugarcane.
In their study, the scientists mapped a genetic locus in the S. viridis genome that controls growth of sterile branches called bristles, which are produced on the grain-bearing inflorescences of some grass species. They discovered that these bristles become spikelets that produce flowers and grain. The conversion is determined and regulated by a class of plant hormones called brassinosteroids (BRs), which modulate a range of physiological processes in plant growth, development and immunity.
The study also showed that localized disruption of BR synthesis can lead to the production of two flowers per spikelet rather than the single one that it typically forms. Eveland said that the discovery of the BR-dependent phenotypes represent two potential avenues for enhancing grain production in millets, including subsistence crops in many developing countries that remain largely untapped for genetic improvement.
For more details, read the news release by Donald Danforth Plant Science Center.
Food derived from Provitamin A rice line GR2E (popularly known as Golden Rice) can be sold in Australia and New Zealand. Food Standards Australia New Zealand (FSANZ) released the approval report for Application A1138 submitted by the International Rice Research Institute seeking approval for food derived from rice line GR2E, genetically modified (GM) to produce provitamin A carotenoids, especially beta-carotene, in the grain.
FSANZ stressed that the approval was meant to prevent trade disruption should Golden Rice be inadvertently present in imported shipments of milled rice, and that GR2E is not intended to be used in the Australian or New Zealand food supplies.
A safety assessment and nutrition risk assessment of GM rice line GR2E are included as supporting documents to the report. No potential public health and safety concerns have been identified. Based on the data provided in the present Application, and other available information, food derived from line GR2E is considered to be as safe for human consumption as food derived from conventional rice cultivars.
For more information, read the Approval Report and supporting documents on the FSANZ website.
The European Commission, on December 22, 2017, has authorized six genetically modified organisms (GMOs), all for food/feed uses. These are:
The GMOs that were approved have all gone through a comprehensive authorization procedure, including a favorable scientific assessment by the European Food Safety Authority (EFSA).
The authorization decisions do not cover cultivation. These GMOs had received "no opinion" votes from the Member States both in the Standing and the Appeal Committees and the Commission therefore had to adopt the pending decisions. The authorizations are valid for 10 years, and any products produced from these GMOs will be subject to the EU's strict labelling and traceability rules.
For more information, read European Commission Daily News.
Characterization of stress-related genes can help understand the mechanisms of plant responses to outside conditions. This study by the team of Yunfei Yang from University of Adelaide in Australia defined the role of wheat TaHDZipI-5 gene.
The TaHDZipI-5 gene encodes a stress-responsive transcription factor during the development of plant tolerance to frost and drought. The researchers found that the gene was strongly induced by low temperatures. There was also elevated TaHDZipI-5 expression in flowers and early developing grains under normal conditions, suggesting that TaHDZipI-5 is involved in regulation of frost tolerance at flowering.
The overexpression of TaHDZipI-5 in bread wheat significantly enhanced frost and drought tolerance of transgenic wheat lines. However, undesired phenotypic features were also present in the transgenics, including reduced plant size and biomass, delayed flowering, and a decrease in yield.
This gene could be a candidate gene for the development of drought and/or frost tolerant wheat. However, further studies are still needed to minimize, if not eliminate, the undesired phenotype caused by its overexpression.
For more on this study, read the article in Plant Biotechnology Journal.
Previous studies have indicated that plant plastocyanins are involved in copper homeostasis. However, their physiological relevance remains elusive. The team of Xin-Tong Zhou of Chinese Academy of Sciences found that a plastocyanin gene, SsPETE2, from seepweed (Suaeda salsa) has a novel antioxidant function, which was associated with its copper-chelating activity.
In S. salsa, the expression of SsPETE2 increased when the plant was exposed to oxidative stress. When SsPETE2 was expressed in Arabidopsis, it enhanced the antioxidant ability of the transgenic plants. The SsPETE2 protein binds to Cu ions and alleviate formation of hydroxyl radicals. Thus, SsPETE2 expression lowers the free Cu content that was associated with plants under oxidative stress.
Interestingly, SsPETE2-expressing plants exhibited more potent tolerance to oxidative stress than plants overexpressing AtPETEs. This means that the SsPETE2 protein has a stronger copper-binding activity than AtPETEs protein.
These results demonstrate that plant PETEs play a role in oxidative stress tolerance by regulating Cu ions in plants under stress conditions. SsPETE2, an efficient copper-chelating PETE, could be potentially used in crop genetic engineering.
For more information, read the article in Plant Science.
Alpine Haircap Moss (Polytrichastrum alpinum) is one of the polar organisms that can withstand the severe conditions of the Antarctic. Hemasundar Alavilli of Sogang University in South Korea isolated a peptidyl prolyl isomerase gene, PaFKBP12, from P. alpinum from the Antarctic and studied its function in plant development and stress responses.
PaFKBP12 expression was found to be induced by heat and ABA. Overexpression of PaFKBP12 in Arabidopsis increased the plant size, stemming from increased rates of cell cycle. Under heat stress, PaFKBP12-overexpressing lines showed better growth and survival than wild types.
The overexpressing lines also showed higher root elongation rates, better shoot growth and enhanced survival at higher concentrations of ABA compared to wild types. Moreover, these lines were also more tolerant to drought and salt stress. All phenotypes were also accompanied by higher induction of the stress responsive genes.
Based on the findings, PaFKBP12 has important functions in plant development and abiotic stress responses.
For more on this study, read the article in Plant Cell Reports.
The ∆ 1 -pyrroline-5-carboxylate synthetase (P5CS) is the rate-limiting enzyme in proline (Pro) synthesis and is involved in drought and salt stress tolerance in plants. An OsP5CS gene was isolated from a stress-treated commercial rice variety, BC15.
The length of rice OsP5CS was 2173 nucleotides, containing an ORF encoding for 716 amino acids with two regulatory amino acid residues Asp and Phe. Amino acid sequence alignment of P5CS proteins indicated that P5CS has homology among rice, corn, tobacco, bean and tomato. BC15 OsP5CS also showed the 99.6% similarity to OsP5CS of GeneBank-registed Nipponbare rice (AC111016.2).
Based on the DNA isolated sequence, four gRNA (guide RNA) constructs were designed for CRISPR-Cas9 editing of BC15 OsP5CS in order to increase the Pro accumulation in cells. This study laid the foundation for the development of high-yielding rice varieties resistant to drought and salinity using genome editing technology.
Read the original article in Vietnamese from the Journal of Agriculture and Rural Development.
Multilocular silique is a desirable agricultural trait with great potential for developing high-yield varieties of Brassica. However, no induced multilocular mutants have been reported in canola (Brassica napus) due to its allotetraploid nature. Yang Yang from Huazhong Agricultural University in China has found the efficient knockout of canola homologues of CLAVATA3 (CLV3) and its related receptors, CLV1 and CLV2, in the CLV signalling pathway using the CRISPR-Cas9 system.
The multilocular phenotype can be achieved only in knockout mutations of the two copies of the BnCLV gene. The double mutation of BnCLV3 produced more leaves and multilocular siliques with a significantly higher number of seeds per silique and a higher seed weight than the wild-type and single mutant plants, potentially contributing to increased seed production.
These findings reveal the potential of CRISPR in improving yield traits in canola varieties.
For more information, read the article in Plant Biotechnology Journal.
Arsenic pollution in soil has been a serious problem all over the world. Hence, it is very important to study plants' stress-response mechanisms for phytoremediation. The team of Yanli Liu from Chinese Academy of Sciences studied the arsenate-tolerant Populus deltoides and the arsenate-sensitive Populus × euramericana to search for the gene for arsenic resistance.
Comparisons between these two cultivars showed that P. deltoides exhibited lesser morphological and structural injury, lower ROS and MDA accumulation, and higher photosynthesis and ROS scavenging ability under arsenate stress compared to P. euramericana.
Analysis revealed that most of the identified arsenate-responsive proteins were stress and defense related. Among these proteins, PdDRT102 was found to be only highly induced in P. deltoides under arsenate stress. Heterologous overexpression of PdDRT102 in Arabidopsis also conferred enhanced tolerance to arsenate and sodium chloride.
Together, these results revealed that PdDRT102 is involved in protecting poplars against arsenate stress and could have the potential to be used for developing crops for phytoremediation against arsenic pollution.
For more information, read the article in Plant Cell Reports.
Science news writers usually define technical terms to make the readers understand the content of their articles. The choice of words, as well as definition of concepts, often has influence on how audiences respond to biotech stories.
The study Seventeen Years of Media Reportage of Modern Biotechnology in the Philippines, published in the April 2017 issue of the Philippine Journal of Crop Science, found that Filipino news writers define modern biotechnology differently, but most of them do not define it at all.
Continue reading at the ISAAA blog.