China’s approval of GM crops energizes researchers

Powdery mildew, seen here growing on wheat, reduces crop yield and quality.Credit: Nigel Cattlin/Alamy

Chinese researchers are excited about their government’s approval of genetically modified crops, which they say pave the way for the use of plants in agriculture and should spur research into tastier, pest-resistant and better varieties. adapted to a warming world.

Since China’s Ministry of Agriculture issued preliminary guidelines on Jan. 24, researchers have rushed to submit applications for the use of their genetically modified crops. These include the development of wheat varieties resistant to a fungal disease called powdery mildew, which are described in an article by Nature this week1.

“This is very good news for us. It really opens the door to commercialization,” says plant biologist Caixia Gao from the Institute of Genetics and Developmental Biology at the Chinese Academy of Sciences in Beijing, who is co-author of the article.

“The decision is a big step forward for China” and will move the research from theory to the field, says Jin-Soo Kim, who heads the Genome Engineering Center at the Daejeon Institute of Basic Sciences, in South Korea.

China’s new rules are more conservative than those of the United States – which does not regulate genetically modified crops that incorporate small changes similar to those that might occur naturally – but are more lenient than the government’s tough stance. European Union to deal with all genetically modified crops. as genetically modified (GM) organisms.

No foreign genes

GM crops are grown using technologies such as CRISPR-Cas9 which can make small changes to DNA sequences. They differ from crops obtained by genetic modification as this usually involves the insertion of entire genes or DNA sequences from other plant or animal species. However, until now, in China, they were covered by the same legislation as that relating to GMOs.

Currently, it can take up to six years to obtain biosafety approval for a GM crop in China. But the researchers say the new guidelines – which set out the process for receiving a biosafety certificate for genetically modified crops – could reduce the approval time to one to two years.

GM crops require extensive and large-scale field trials before being approved for use. New guidelines state that for GM crops deemed to pose no risk to the environment or food safety, developers need only provide laboratory data and conduct small-scale field trials .

However, the researchers say some of the guidelines are ambiguous. They apply to cultures in which gene editing technology is used to delete genes or make single nucleotide changes, but it is unclear whether they also apply to cultures in which gene sequences DNA have been introduced from other varieties of the same species.

“We’ll have to confirm whether these are allowed,” because it’s important to clarify the rules, says Chengcai Chu, a rice geneticist at South China Agricultural University in Guangzhou.

Already, researchers plan to focus more of their work on developing new crops that will be useful to farmers. For example, Jian-Kang Zhu, a plant molecular biologist at Southern University of Science and Technology in Shenzhen, says he wants to develop genetically modified varieties that have increased yields, resistance to climate change and better response to fertilizers. .

Others are preparing applications for particularly aromatic rice and high oleic fatty acid soybeans, which could produce an oil low in saturated fat.

Resistance and growth

Gao’s powdery mildew-resistant wheat could be one of the first to be approved. In 2014, she and her team used gene editing to remove a gene that makes wheat susceptible to fungal disease, but discovered that these changes also slowed plant growth.2. However, one of their modified plants grew normally and the researchers found that this was due to the deletion of part of the chromosome, which meant that the expression of a gene involved in sugar production did not was not suppressed.

Since then, researchers have been able to remove that same part of the chromosome, in addition to the gene that makes the plant susceptible to powdery mildew, creating fungus-resistant varieties of wheat that do not suffer from restricted growth.

“This is a very comprehensive and beautifully done piece of work,” says Yinong Yang, a plant biologist at Pennsylvania State University at University Park. It also has broad implications for almost all flowering plants, he says, as powdery mildew can infect some 10,000 species of plants.

“It’s really exciting work,” adds David Jackson, a plant geneticist at Cold Spring Harbor Laboratory in New York, though he cautions that the wheat growth data was based on relatively few plants grown largely in greenhouses and will need to be confirmed by larger field trials.

Studies like this are a testament to China’s strong track record in researching GM crops, and the new regulations “should allow China to take full advantage of its academic lead,” says plant scientist Penny Hundleby. at the John Innes Center. in Norwich, UK.

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