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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August 8, 2018
In This Week’s Issue:
News
Global
The Need for GM Wheat
New Multiple Gene Stacking Technique Could Develop Crops with Higher Yields and Better Traits
Regulatory and Policy Officials of APEC Economies Briefed on Biotechnology and Plant Breeding Innovations
Americas
Key Gene for Sugarcane Growth Has Been Identified
Researches Report Protein that Controls Flowering thru Combined on and off Switches
U.S. Dept of Interior Ends Ban on GE Crops and Neonicotinoid Pesticides in Refuge
Asia and the Pacific
New Genome of Chinese Soybean Now Available
Scientists Narrate Past, Present, and Future of the Bt Eggplant Project in Bangladesh
Europe
European Commission Authorizes Five GM Crops
Poland Releases Draft GE Labeling Legislation
Research
Rice OsRACK1A Gene Negatively Regulates Salt Tolerance
TaWRKY2-Overexpression Enhances Drought Tolerance in Wheat
New Breeding Technologies
Researchers Edit Yield-Increasing Genes in Rice
Regulator of Symbiotic Nodulation in Lotus Found
Study Reveals the Role of Malate Transporters in Rice Grain Yield
CRISPR Gene-Editing Technology, Better with Cas12a
Beyond Crop Biotech
SCI+POP, A New Social Media Project in Canada
Study Shows Poplar Trees Can Be Genetically Engineered Not to Spread
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NEWS
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Global
THE NEED FOR GM WHEAT
Although providing ~20% of the daily calories and protein per capita worldwide, wheat is relatively an outcast from the posse of biotech crops. Scientists address this "abandonment" issue in a perspective article in Science.
The authors presented a promising shorter time for wheat improvement via genetic engineering than traditional crossbreeding and speed breeding, as well as the loss of resistance and tolerance genes caused by wheat domestication. The need for GM wheat is intensified by the devastating effect of wheat blast, which also has possible negative effects on rice cultivation.
Africa and Asia, the two most populous regions with high incidences of malnutrition and poverty, will be the primary benefactors once GM wheat is developed.
For more information, read the article in Science.Scientist from the USDA Agricultural Research Service developed a new process that can be used to insert multiple genes into a crop plant, which can make it easier to breed a variety of crops with highly enhanced characteristics. The new process is reported in The Plant Journal.
The new process called GAANTRY gene stacking technology is expected to hasten the development of new varieties of potatoes, rice, citrus, and other crops with improved tolerance to heat and drought, produce higher yields, and resist a myriad of diseases and pests. The process includes stabilizing large "stacks" of DNA necessary to express vital characteristics, letting the researchers to insert suites of genes so precisely that no unintended DNA is added or removed during the process.
"Making genetic improvements that were difficult or impossible before will be much easier because we can now insert not just one or two genes, but multiple genes, into a plant in a way that will lead to predictable outcomes," said Roger Thilmony, a molecular biologist from ARS. "Before this, assembling 10 genes to insert into a new line would be difficult or impossible, but this technology basically stabilizes the stack and create results that are more stable and much easier to predict," Thilmony added.
Read more from USDA-ARS.
The High Level Policy Dialogue on Agricultural Biotechnology workshop of the Asia Pacific Economic Cooperation (APEC) economies was concluded in Brisbane, Australia on August 1-3, 2018. Regulatory and policy officials from 16 APEC and three non-APEC economies converged to exchange the most current information on the most pressing issues affecting innovative technologies while building relationships among APEC members.
The first part of the program was devoted to a day of discussions on regulatory cooperation where experts and economies identified the best practices or tools that APEC economies can use to promote greater alignment of APEC economies' standards with relevant international standards. The second part of the workshop was a two-day discussion on plant breeding innovations, including the new tools such as genome editing, and an overview of the state of science and product development. Selected economies were invited to share on-going domestic discussions regarding innovative plant breeding developments, as well as policy and regulatory aspects.
In addition, a session on communication and public acceptance of products from biotechnology and plant breeding innovation was conducted to aid participants in increasing global public awareness.
The workshop was funded by the US Department of Agriculture, Foreign Agricultural Service and the US-APEC Technical Assistance to Advance Regional Integration.
For details, contact knowledge.center@isaaa.org.
A team led by Professor Marcelo Menossi at the University of Campinas's Biology Institute (IB-UNICAMP) in Brazil has found that the key to overcoming a major constraint on sugarcane yield could lie in a gene called ScGAI.
Sugarcane yields have been static for decades due to the constraints on culm development. The culm's sugar storage capacity is physically limited, restricting the volume of sucrose and biomass that can be obtained from the crop for sugar and ethanol production.
Menossi said that breaking through this developmental threshold by conventional breeding has been difficult. His team discovered that ScGAI is an important regulator of culm development, and manipulating its activity increases culm volume and changes the allocation of carbon to structural and storage molecules.
ScGAI was also found to mediate the regulation of sugarcane developmental hormones, such as ethylene and gibberellins. Gibberellins are widely used to improve yields and accelerate sugarcane ripening by triggering the rapid degradation of DELLA proteins, which are thereby prevented from interacting with and degrading other proteins that stimulate culm development.
For more details, read the news article from Agencia FAPESP.
A research published in Nature Genetics and conducted by University of WisconsinMadison biologists presents a previously unknown mechanism for controlling cellular decisions, one which combines an on-and-off switch in a single protein.
Geneticist Xuehua Zhong and her lab at Wisconsin Institute for Discovery found that the protein EBS can bind to two different chemical modifications on histones, proteins that DNA wraps around, either promoting or preventing the transition to flowering in plants. This provides opportunities for developing better crops and could also help scientists in studying detrimental diseases such as cancer.
Gene activation is usually controlled by one protein, while another protein will block the gene's epression. However, Zhong's team found that EBC has domains that can read both activating and repressing marks, and then make the switch turn on or off. They also reported that during flowering time, EBS changes its shape, making it more linked to the activating modifications. That transformation from "off" to "on" allows EBS to switch on a group of genes that activates the flowering program.
Read the media release from the University of Wisconsin-Madison.
The U.S. Department of Interior (DOI) Fish and Wildlife Service announces the full withdrawal of the July 2014 memorandum stating that certain agricultural practices, particularly the use of genetically engineered (GE) seeds and neonicotinoid pesticides across the National Wildlife Refuge System (NWRS) would be phased out in refuges. The announcement of withdrawal, thus reverses the decision to universally ban the GE crops on refuges.
According to the new memorandum, NWRS will now determine the appropriateness of the use of those crops and neonicotinoid pesticides on a case-by-case basis, in compliance with all relevant and controlling legal authorities. It was also mentioned in the new memorandum that there may be situations where use of GE seeds is essential to best fulfill the purposes of the refuge and the needs of the birds and other wildlife.
Read the memorandum from DOI.
Chinese scientists have released a new high-quality soybean genome for a Chinese soybean "Zhonghuang 13". This genome, together with a subsequently established comprehensive gene co-expression network, facilitates important agronomic genes mining and provides valuable information for future soybean elite cultivar improvement.
The current soybean reference genome sequenced from Williams 82 is a cultivar domesticated in America. As Asia is one of the largest soybean planting and consuming regions, its soybean production is essential for global food security, and a new high-quality soybean genome from Asian soybean accessions is necessary.
The researchers identified a large number of genetic variations between this genome with a commonly used soybean reference genome, including 1,404 translocations, 161 inversions, 1,233 translocation and inversions, 505,506 indels (1-99 bp), and 17,409 accession specific insertions (>=100 bp). A total of 36,429 transposable elements and 52,051 protein coding genes were annotated in the new genome.
For more details, read the research news at the Chinese Academy of Sciences website.
Since the approval of Bt eggplant for "limited cultivation" in Bangladesh in 2013, ~17% of the total brinjal farmers in the country are already benefiting from the technology. Scientists concisely report the history, present status, and future direction of the Bt eggplant project in Bangladesh in a perspective article in Frontiers in Bioengineering and Biotechnology.
The highlights of the report include the creation, approval process, adoption, performance, economic effects, and sustenance of the technology. Comments on the future direction of the technology are summarized and include the following:
The research team believes that Bt brinjal is important in the future of other genetically engineered crops in Bangladesh.
For more information, read the article in Frontiers in Bioengineering and Biotechnology.
The European Commission authorized 5 genetically modified (GM) crops for food and feed. These include two new varieties of maize (MON 87427 x MON 89034 x NK603 and 1507 x 59122 x MON 810 x NK603), and renewal of 3 existing authorizations for maize (2) and sugarbeet (DAS-59122-7, GA21, and H7-1, respectively).
According to the Commission, each of the authorized GM crops were evaluated by the European Food Safety Authority (EFSA), which released favorable opinions about the safety of the GM crops. The authorizations are valid for 10 years, and are subject to EU's strict labeling and traceability rules, which include proper labeling of products stating "genetically modified" or "produced from genetically modified organism." However, if the product has less than 0.9% of GM ingredients, or if the addition of the GM is adventitious or technically unavoidable, such labeling is not required.
Read the press release from the European Commission.
The draft standard states that a "non-GMO" label would be placed on the packaging of such products. The draft legislation will be submitted to the Upper Chamber of Polish Parliament in fall 2018, after receipt and consideration of public comments. According to the Ministry, the draft Act was a response to the requests of the public, including consumer organizations and industry groups so they can differentiate between GE and non-GE products.
Read more from the USDA FAS-GAIN Report.
The receptor for activated C kinase 1 (RACK1) is a protein involved in multiple signaling pathways. Yangzhou University's Dongping Zhang, together with researchers from various Chinese universities, studied the rice RACK1A (OsRACK1A) to learn its role in salt stress response.
Analysis showed the OsRACK1A follows a rhythmic expression pattern under circadian conditions. Suppression of OsRACK1A resulted in enhanced tolerance to salt stress. OsRACK1A-suppressed transgenic rice also accumulated more abscisic acid (ABA) and had upregulated ABA- and stress-inducible genes. Furthermore, researchers found that the OsRACK1A protein interacts with many salt stress-responsive proteins directly.
These results suggest that OsRACK1A is regulated by circadian rhythm, and involved in the regulation of salt stress responses.
For more information, read the article in Rice.
Drought is a major stress severely affecting plant growth and crop productivity. A previous study showed that TaWRKY2 from wheat plays an important role in drought stress tolerance. Chinese Academy of Sciences researchers led by Huiming Gao further studied the TaWRKY2 gene and its promoter.
The TaWRKY2 promoter was found to be induced by drought, salt, and heat stresses as well as abscisic acid (ABA). The team then generated TaWRKY2-overexpressing transgenic wheat, and found that these seedlings exhibited significantly enhanced tolerance to drought stress compared with wild type plants. Moreover, the transgenic lines had higher contents of free proline, soluble sugars, and chlorophyll.
During a prolonged drought stress before the heading stage, the growth of wildtype plants was inhibited, while the TaWRKY2-overexpressing lines progressed to the heading stage. The cumulative effects of drought stress resulted in increased grain yield in transgenic wheat.
TaWRKY2 was found capable of enhancing drought tolerance and increasing grain yield in wheat. The gene is a promising candidate for improving the drought tolerance of wheat cultivars.
For more information, read the article in Frontiers in Plant Science.
Rice yield is an important and complex agronomic trait controlled by multiple genes. Several yield-associated genes in rice have been studied, many of which can increase production with their loss of function. However, mutations occurring randomly have provided very limited genetic resources for studying yield increases.
Scientists from China used CRISPR-Cas9 to edit two yield-increasing genes in rice. Team leader Liyu Huang, together with Yunnan University research team edited the Grain number 1a (Gn1a) and DENSE AND ERECT PANICLE1 (DEP1) genes. Phenotypic analysis of the generated mutants confirmed one mutant allele of Gn1a and three of DEP1, all of which confer yield superior to that of other high-yield alleles.
These results demonstrate that favorable alleles of the Gnla and DEP1 genes could be developed by artificial mutagenesis using genome editing technology.
For more information, read the article in The Crop Journal.
During the establishment of rhizobia‐legume symbiosis, the cytokinin receptor LHK1 (Lotus Histidine Kinase 1) is important for nodule formation. However, the mechanism on how cytokinin signaling regulates symbiosis remains unknown. To learn more about this, researchers led by Kai Cai from Huazhong Agricultural University in China studied the LHK1-interacting protein in lotus (Lotus japonica), LjCZF1.
LjCZF1 is a C3HC4‐type RING finger protein that is highly conserved in plants. LjCZF1 specifically interacted with LHK1 in several assays conducted in tobacco. Expression of LjCZF1 was upregulated significantly after inoculation with rhizobia. The generated CRISPR-Cas9 LjCZF1-knockout mutant lotus plants exhibited significantly reduced number of infection threads and nodules. On the other hand, transgenic plants overexpressing LjCZF1 exhibited increased numbers of infection threads and nodules.
These results suggest that LjCZF1 is a positive regulator of symbiotic nodulation.
For more information, read the article in Journal of Integrative Plant Biology.
Panicle size is a critical factor in grain yield in rice and other grain crops. During rice growth and development, spikelet abortion often occurs at either the top or the basal part of the panicle under unfavorable conditions, causing a reduction in grain yield. Yueqin Heng from the Chinese Academy of Agricultural Sciences studied a rice panicle abortion mutant, panicle apical abortion1-1 (paab1-1), to learn more about spikelet abortion.
The paab1-1 mutant exhibits degeneration of spikelets on the apical portion of panicles during late stage of panicle development. Analysis revealed that the apical spikelets in the paab1-1 mutant undergo programmed cell death. Further analysis revealed that paab1-1 possesses a mutation in the OsALMT7 gene, which encodes an aluminum-activated malate transporter in the plasma membrane, and is expressed in the vascular tissues of developing panicles.
The panicle of the paab1-1 mutant had less malate than wildtypes at the apical portions. Furthermore, injection of malate into the paab1-1 panicle could rescue the spikelet degeneration phenotype. CRISPR-Cas9 knockout of OsALMT7 in rice further confirmed the function of the gene, as the generated CRISPR mutants exhibited the same panicle abortion phenotype as the paab1-1 mutant.
These results suggest that OsALMT7-mediated transport of malate into the apical portion of panicle is required for normal panicle development, highlighting a key role of malate in maintaining the sink size and grain yield in rice.
For more information, read the article in The Plant Cell.
Cas9 is the first enzyme used in the CRISPR gene-editing technology. As if the tool could not get any better, researchers from The University of Texas at Austin found that Cas12a, which is more popularly known as Cpf1, is more precise in targeting genes for modification than Cas9.
Through quantitative kinetics, the team determined the specific gene-targeting mechanism of CRISPR-Cas12a. Results showed that Cas12a works like a "velcro" in the system, whereas Cas9 works like a "super glue." Thus, reversibility is possible with Cas12a, consequently reducing off-targets.
For more information, read the articles in UT News and Molecular Cell.
Among the strategies that they deem effective in communicating science were works that invite critical thinking, narratives that resonate with the audience, and the usage of artistic images. They focused on the use of artistic images to address misinformation and conspiracy theories involving controversial science topics.
The following are their bases for the usage of visual images:
For more information, read the article in The Conversation.
The largest field-based study of genetically modified (GM) forest trees has shown that genetic engineering can prevent new seedlings from establishing.
Poplars are fast growing trees and the source of many products, from paper to pallets to plywood to frames for upholstered furniture. Poplars have female and male trees, where female flowers produce the seeds and male flowers make the pollen needed for fertilization. The Oregon State University study led by Professor Steve Strauss looked at 3,300 poplar trees in a 9-acre tract over seven growing seasons. Strauss and colleagues assessed different approaches to make both genders of poplar sterile, focusing on 13 genes involved in the making of flowers or controlling the onset of reproduction.
The research team discovered modifications that prevented the trees from producing viable sexual propagules without affecting other traits, and did so reliably year after year. The studies focused on a female, early-flowering poplar that facilitates research, but the genes they targeted are known to affect both pollen and seed, and thus should provide general approaches to containment.
For more details, read the news release from Oregon State University.