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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May 31, 2017
In This Week’s Issue:
News
Global
• Global Team Led by ICRISAT Re-sequence Pigeonpea Genome
Africa
• Journalists in Uganda Urged to Support Passing of Biotech Law through Factual Reporting
• Kenya Biosafety Regulators Commend Malawi's Bt Cotton National Performance Trials
Americas
• Two New Proteins Connected to Plant Development Identified
• Draft Genome of Spinach Published by Researchers from US and China
• Research Team Discovers Gene that Impacts Soybean Nodule Development
• Engineered Rice with Adjustable Immune System Shows Resistance to Multiple Diseases at Once
Asia and the Pacific
• Japan, A Potential Biotech Sugar Beet Country
Europe
• Study Shows Climate Change to Cause 23% Decline in Crop Production by 2050s
Research
• Researchers Study the Effect of Calcareous Soil on Bt Protein Expression and Efficacy in the Field
• CAAS Scientists Develop Herbicide Resistant Cotton with Low Glyphosate Residues
New Breeding Technologies
• CRISPR-mediated Targeted Mutagenesis in Grape
• Simultaneous Targeting of Multiple Gene Homeologs to Alter Oil Production in Camelina
Beyond Crop Biotech
• PtrMYB57 Transcription Factors Negatively Regulate Anthocyanin and Proanthocyanidin Synthesis in Poplar
• Plant-Produced Vaccine Candidate for Bluetongue Virus
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NEWS
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Global
GLOBAL TEAM LED BY ICRISAT RE-SEQUENCE PIGEONPEA GENOME
A global team of 19 scientists from 9 institutes led by India-based International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) have re-sequenced the genome of 292 pigeonpea varieties (Cajanus cajan) from 23 countries and discovered new traits including resistance to diseases that affect the crop and its insensitivity to photoperiod.
Dr. Rajeev K Varshney, Research Program Director at ICRISAT, and the project director, said that the study used re-sequencing data to identify genomic regions impacted by domestication and breeding; identified the genetic origin of the crop at a DNA level for the first time; and identified genes with agronomically useful traits such as resistance to sterility mosaic disease and Fusarium wilt, and insensitivity to photoperiod that will help to accelerate pigeonpea breeding and reduce the time to develop superior varieties from 8-10 years to 5 years. The team also identified the gene "efl3" for making pigeonpea photoperiod insensitive. The research also traces the likely origin of the domesticated pigeonpea to Madhya Pradesh in central India.
ICRISAT's Director General, Dr. David Bergvinson, highlighting the importance of the study, said, "Pigeonpea is a very important commercial crop for smallholder farmers in Africa and Asia as it has a huge export potential. This breakthrough will help us better understand the grain's quality traits and unlock the huge potential of this crop and allow farmers access to high-value markets. Understanding the photoperiod sensitivity is an example as this will allow the crop to be established in many regions where it is currently not grown."
For more details, read the media release from ICRISAT.
The Director for Crop Resources in the Ministry of Agriculture, Animal Industry, and Fisheries (MAAIF), Mr. Okasaai Opolot, has appealed to journalists in Uganda to increase their efforts in informing the public about the products of modern biotechnology. He also urged them to enhance their efforts in helping the policy makers appreciate the relevance of regulating this technology so as to hasten the process of making the National Biotechnology and Biosafety Bill into law. He noted that his Ministry is committed to supporting the Minister for Science and Technology to get the Bill passed. Mr. Opolot, who represented the Minister of Agriculture as Chief Guest at the maiden Uganda Biotechnology Media Awards held on May 26, 2017 at Sheraton Kampala Hotel, commended the journalists for being committed to reporting about agriculture including the advances in biotechnology. He encouraged them to always report factual information. He challenged the organizers and all biotech communicators to ensure that all media houses in the country are ably equipped to report about biotechnology and biosafety.
The Media Awards was organized by the Uganda Biosciences Information Center (UBIC) to recognize the commitment of journalists in reporting about complex scientific topics like biotechnology, and for increasing public awareness of these modern sciences. The event was organized in collaboration with Program for Biosafety Systems (PBS), Uganda Biotechnology and Biosafety Consortium (UBBC), WEMA Project Uganda, and Science Foundation for Livelihood and Development (SCIFODE). A total of 27 submissions were received in radio, print, online, and television reporting. The journalists received crystal plaques and different tokens to help them improve the quality of their reporting.
A keynote address on Improving Science Communication in the Media was delivered by Mr. Charles Odoobo Bichachi—the Executive Editor of the Daily Monitor newspaper. He cautioned the journalists to take their time to do research on the topic in science and/or agriculture so that they are well-informed even before starting to write. "Write the complete picture including answers to the anticipated questions that readers will be asking, for example, when you talk about recently released seeds, tell the farmers where to get them," he added. He warned scientist against having conversations only among themselves instead they should invest more in conversations with end-users of the products they are developing.
The Chairperson of the Judges, Dr. Charles Wendo, Chairperson for the Uganda Health Communication Alliance, noted that the quality and number of submissions received were a good indicator of the courage and commitment of journalists to creating mass awareness about the relevance of products and regulation of biotechnology. He called for more inclusion of the voices of extension workers in biotechnology education and awareness.
UBIC's Coordinator—Dr. Barbara Zawedde—thanked the journalists for their efficient reporting and urged them to encourage more of their peers to partner with scientists to help the populace to make informed decisions on biotechnology.
Contact the UBIC Coordinator for more information: ubic.nacrri@gmail.com.
A high-level delegation from Kenya visited Malawi's Bt cotton National Performance Trial (NPTs) fields on May 11, 2017. The team consisted of board chairs from the National Environment Management Authority (NEMA), Kenya Plant Health Inspectorate Service (KEPHIS), Kenya Agricultural and Livestock Research Organization (KALRO), as well as the Managing Director of RIVATEX, a textile company in Kenya. Farmers, media, and other key players were also represented.
The tour's objective was to share Malawi's regulatory experience in the conduct of NPTs and was hosted by the Department of Agricultural Research Services (DARS). Mr. Thomas Chilanga, Deputy Director of DARS encouraged the Kenyan delegates to work together to surmount the challenges facing conduct of NPTs in Kenya. "Necessity is the mother of inventions. Malawi's Bt cotton journey has not been smooth, actually, it was a crisis that gave us the impetus to go into Bt cotton research. Field days for farmers and use of mass media including local radio stations to share correct information was very crucial for Malawi," he said.
The delegates had an opportunity to see first-hand the efficacy of Bt cotton, learn about Malawi's NPT experimental design and interrogate an array of issues, including cross-pollination, performance of different cotton hybrid varieties and the effect of spraying against cotton bollworm for both biotech and conventional cotton.
While admitting that it was his first interacting with Bt cotton researchers both locally and regionally, NEMA chair, Mr. John Konchellah expressed support for Kenya's NPTs to enable the country to move to the next stage. "There is no doubt at least for Bt cotton. I will get on board even if its by-product will be used for animal feed, I have no problem. I feel for the scientists particularly the young generation who are trying to take their space in the scientific world yet we don't offer opportunities for them to apply acquired knowledge for societal benefit," said Mr. Konchellah.
The seeing-is-believing study tour was organized by ISAAA AfriCenter, in collaboration with Malawi's Ministry of Agriculture, Irrigation and Water Development, the Program for Biosafety Systems (PBS) and Common Market for Eastern and Southern Africa (COMESA) through its specialized agency, the Alliance for Commodity Trade in Eastern and Central Africa (ACTESA).
For more information, contact Dr. Margaret Karembu of ISAAA AfriCenter at mkarembu@isaaa.org.
Two new proteins, RICE1 and RICE2, were discovered by a team of researchers led by biochemist Dr. Xiuren Zhang from Texas A&M AgriLife Research. The proteins could help study better ways to regulate plant structure and the ability to resist crop stresses such as drought.
Dr. Zhang said that understanding RNA silencing is important so that researchers can use the technique to help a plant overcome barriers to growth or ability to deal with unfavorable environments by tweaking the amount of RNA. A key player in RNA silencing is RISC (RNA-induced Silencing Complex), which contains microRNA and enzymes called AGOs. "MicroRNA starts as twins, so to speak, but one of the twins leaves and disappears when AGO protein moves in," Zhang said.
Using proteomic analysis, Dr. Zhang and colleagues deciphered the constituents of one kind of RISC in Arabidopsis and found proteins RICE, or RISC-Interacting Clearing Exoribonuclease. RICE1 was found to have a ring-like structure with six identical molecules. Analysis of the shape of RICE1 revealed its active region which is responsible for degrading RNA fragments, hidden on the adjacent site of two RICE molecules.
For more details, read AgriLife Today.
Researchers from Boyce Thompson Institute (BTI) and the Shanghai Normal University report a new draft genome of spinach (Spinacia oleracea). The researchers have sequenced the transcriptomes (all the RNA) of 120 cultivated and wild spinach plants, which allowed them to identify which genetic changes have occurred due to domestication.
The researchers found that the genomes of cultivated spinach varieties are not too different from their wild progenitors. Spinach, native to Central Asia, is now cultivated worldwide. Genomic information available to researchers today can help in fighting significant diseases, such as downy mildew.
With a better understanding of the spinach genome, the research team has identified several genes that may confer resistance to the downy mildew pathogen. Once identified in a resistant variety of spinach, the genes could be quickly transferred to other, possibly more nutritious varieties, boosting their immune systems to fight this disease while still maintaining marketable traits.
For more information, read BTI News.
In a study that aims to increase soybean plants' nitrogen-fixing ability, and thus reduce the need for chemical fertilizers, a research team from the University of South Dakota has discovered that the gene SUR2 plays a key role in the production of auxin, a hormone that affects nodule development in soybean plants.
Soybean interacts with bacteria in the soil to form nodules. Within the nodules, two distinct zones—one that fixes nitrogen, and another that transports it to the plant—are formed from pre-existing root cells. The expression of specific genes in a particular root cell determines its function.
Led by associate plant science professor Senthil Subramanian, the team has previously observed that auxin reduced the number of nodules in soybean plants. Doctoral student Suresh Damodaran then focused on identifying genes that regulate auxin levels in the nodules. When Damodaran reduced the expression of the SUR2 gene, thus increasing auxin production, the plant produced fewer nodules. However, when auxin levels were reduced, the nodule numbers increased.
For more details, read the article at AgroNews.
Scientists have successfully engineered a rice plant with an adjustable immune system to make it resistant to multiple diseases at once without decreasing its yield.
"For as long as I have been in this field, people have been scratching their heads about how to activate a defense system where and when it is needed," says Jonathan Jones, a professor at the Sainsbury Laboratory in Norwich, U.K. "It is among the most promising lines of research in this field that I have seen."
The gene known as NPR1 has been explored by many scientists to improve the immune system of rice, wheat, apple, and other plants. Duke University scientist, Xinnian Dong, has been studying this gene for two decades and referred it as the "master regulator" of plant defense. When this gene is turned on for immunity, it backfires on the growth of the plant resulting to stunting and zero production for farmers. This led Dong and other researchers to another immune system-activating protein in Arabidopsis, the TBF1. They discovered a complicated system that involves readily available messenger RNA molecules that encode TBF1, and instantly translating these molecules into TBF1 proteins, causing an immune response. Dong copied the segment of the DNA that functions as a switch for immune response and placed it alongside and in front of the NPR1 in rice. This led to a rice plant with boosted immune system strong enough to ward off pathogens in short periods of time to avoid stunting. The engineered rice has shown effective resistance against rice blight (Xanthomonas oryzae pv. oryzae), leaf streak (X. oryzae pv. oryzicola), and blast disease (Magnaporthe oryzae).
Read the original article from Science.
Japan has the potential to adopt biotech crops in the future with the increasing importation of biotech maize, soybean, canola, and cotton, which in 2016 was recorded at 20.9 million metric tons. About 90% of these crops were genetically modified (GM). The country leads globally in biotech crop approvals, however, no biotech crop was ever planted. This was put forward by Dr. Fusao Tomita, director of Nippon Biotechnology Information Center (NBIC) during the seminar launch of ISAAA Brief 52, Global Status of Commercialized Biotech/GM Crops: 2016 in Tokyo, Japan. Dr. Tomita opined that Hokkaido farmers are interested in planting biotech sugar beet and consumers should be educated on substantial equivalence of sugar derived from biotech and non-biotech sugar beet.
Dr. Rhodora R. Aldemita of ISAAA presented the highlights of the ISAAA Brief 52, emphasizing on the approval of virus resistant biotech papaya for consumption since 2011 in Japan. There is also an ongoing limited planting of biotech carnation and rose in Japan in covered facilities, but no biotech crops are being cultivated. Dr. Yasufumi Imai and Dr. Yoshiki Fujimura, both from the Council for Biotechnology Information Japan (CBIJ) gave the opening remarks and the message, respectively.
The seminar launch was organized by CBIJ in cooperation withNBIC with 120 participants, including the media, government representatives, academe, and the industry at Station Conference Tokyo, Tokyo, Japan on May 30, 2017. For more information, visit the Brief 52 homepage on the ISAAA website.
Climate change, which causes extreme weather and temperature, is projected to cause a 23 percent decline in the global output of major crops including corn, wheat, rice, and soybean in the 2050s, according to a study.
Mekbib Haile, a researcher at the Center of Development Research at the University of Bonn, Germany, and colleagues analyzed the price and production of the major crops from 1961 to 2013. A significant decrease of 9% in the global output of the major crops is expected to be evident by 2030s. The negative impacts of climate change were projected to be manifested in several countries by 2030s but will be more pronounced in all countries by 2050s. According to Haile, the increase in average temperatures during the growing season does not have much effect on the staple crops until they hit a particular "tipping point", which is around 89 °F (32 °C). Aside from temperature, extreme weather conditions such as drought and too much rainfall could decrease the production of the crops.
To address these concerns, Haile recommended improvements in farming such as the use of biotech crops, better irrigation, and less tilling.
Read more from The Daily Climate.
Scientists from the University of Nebraska-Lincoln and partners conducted a study to investigate if calcareous soil conditions and associated poor maize growth negatively affect the expression of Cry3Bb1. The results are published in Transgenic Research.
Expression levels of Cry3Bb1 protein were measured in plants at V5–V6 growth stage using the enzyme-linked immunosorbent assay. The researchers artificially infested Cry3Bb1 and non-Bt near isoline maize hybrids with Cry3Bb1-susceptible western corn rootworm eggs to measure survival and efficacy of Cry3Bb1 maize in calcareous and non-calcareous soils.
Results showed that there was no significant difference in expression of Cry3Bb1 protein between plants from calcareous and non-calcareous soils. It was also observed that higher survival rate of western corn rootworm in non-Bt than the Cry3Bb1 maize, which proved that Cry3Bb1 performed as expected when infested with a Cry3Bb1 susceptible rootworm population.
Based on the findings, Cry3Bb1 expression levels provide appropriate root protection against western corn rootworm regardless of soil environment, indicating that lowered Cry3Bb1 expression is not a contributing factor to the greater than expected WCR injury observed in some southwestern Nebraska maize fields.
Read the abstract in Transgenic Research.
Glyphosate resistant crops have been widely adopted by North and South American farmers. However, the adoption of glyphosate resistant crops in China has been hampered by several factors, including labor markets and the residual effects of glyphosate in transgenic plants.
Chengzhen Liang from the Chinese Academy of Agricultural Sciences reported the co-expression of codon-optimized forms of GR79 EPSPS and N-acetyltransferase (GAT) genes in cotton. Two co-expression cotton lines, GGCO2 and GGCO5, exhibited five times more resistance to glyphosate with a 10-fold reduction in glyphosate residues.
The GGCO2 line was then used in a hybridization program to develop new glyphosate resistant cotton varieties. Field trials consisted of three growing seasons showed that pGR79-pGAT transgenic cotton lines had the same agronomic performance as conventional varieties, but were cheaper to produce per hectare.
The strategy to pyramid these genes offers an attractive approach for engineering and breeding of highly resistant low-glyphosate-residue cotton varieties.
For more information on the study, read the article in Plant Biotechnology Journal.
RNA-guided genome editing using the CRISPR-Cas9 system has been applied successfully in several plant species. However, there have been only a few reports on the use of any of the current genome editing approaches in grapes (Vitis vinifera L.).
The team of Ikuko Nakajima from the National Agriculture and Food Research Organization in Japan successfully performed targeted mutagenesis in grape using the CRISPR-Cas9 system. The team designed a construct targeting the phytoene desaturase (VvPDS) gene in grapes and transformed it into embryonic calli.
The resulting regenerated plants exhibited albino leaves. DNA sequencing confirmed that the VvPDS gene was mutated at the target site in regenerated grape plants. Interestingly, the mutated cells were higher in lower, older, leaves compared to that in newly appearing upper leaves.
For more on this study, read the article in PLOS One.
Camelina sativa can easily be genetically modified using enzymes from other plants, making it an ideal platform for the production of unusual valuable lipids. However, suppression of endogenous enzyme activity to reduce competition for substrates, such as triacylglycerol, is also required to enhance the production of target compounds. Furthermore, camelina possesses a hexaploid genome, with multiple gene homeologs coding for an enzyme.
Kansas State University researchers designed a guide RNA identical to all three CsDGAT1 or CsPDAT1 homeologs, to demonstrate the ability of the system in introducing mutations to the genes important for triacylglycerol (TAG) synthesis in developing seeds. Analysis from the edited T1 plants revealed that each CsDGAT1 or CsPDAT1 homeolog was altered by multiple mutations, resulting in a genetic mosaic in the plants.
Seeds harvested from both CsDGAT1- and CsPDAT1-targeted lines were often shrunken and wrinkled. Furthermore, lipid analysis revealed that many lines produced seed with reduced oil content and altered fatty acid composition, consistent with the role of the targeted genes.
CRISPR-Cas system therefore represents a useful method to alter endogenous biosynthetic pathways efficiently in polyploid species such as camelina.
For more on this study, read the article in Plant and Cell Physiology.
Previous studies have identified that R2R3-MYB transcription factors are involved in anthocyanin and proanthocyanidin (PA) biosynthesis in poplar (Populus sp.). Researchers from various universities in China now report the identification and characterization of PtrMYB57. PtrMYB57 was found to encode R2R3 MYB protein localized in the nucleus and is expressed in mature leaves.
Transgenic poplar overexpressing PtrMYB57 exhibited a reduction in anthocyanin and PA accumulation compared to wild types. In contrast, high anthocyanin and PA levels were observed in Ptrmyb57 mutants. Furthermore, assays revealed that the PtrMYB57 transcription factor interacts with bHLH131 (bHLH) and PtrTTG1 (WDR) to form the MBW complex and binds to the flavonoid gene promoters, leading to inhibition of the promoters.
These results suggest that PtrMYB57 negatively regulates anthocyanin and PA biosynthesis in poplar.
For more on this study, read the article in Plant Cell Reports.
Bluetongue is a disease of domestic and wild ruminants caused by the bluetongue virus (BTV), which have caused serious outbreaks worldwide. Commercially available vaccines are live-attenuated or inactivated virus strains, which are not able to distinguish naturally infected animals from vaccinated animals. Recombinant vaccines are preferable to minimize the risks related to these vaccines.
The team of Albertha R. van Zyl from the University of Cape Town in South Africa developed two plant-produced vaccines, Zera®-VP2ep and Zera®-VP2. Both these candidate vaccines were made in tobacco (Nicotiana benthamiana) via transient Agrobacterium-mediated expression, and analysis showed that the proteins accumulated within the cytoplasm of plant cells.
Preliminary studies showed that the two vaccine candidates elicited anti-VP2 immune responses in mice. These results prove that Zera®-VP2ep and Zera®-VP2 can be potential BTV vaccines.
For more on this study, read the article in BMC Biotechnology.