Researchers in China are ecstatic about their government's approval of gene-edited crops, claiming that it clears the way for the plants' usage in agriculture and would stimulate research into varieties that are tastier, pest-resistant and more adaptable to a warming world.
Researchers have been rushing to submit applications for the use of their gene-edited crops since China's agricultural ministry released preliminary guidelines on January 24. These include the development of wheat varieties resistant to a fungal disease called powdery mildew.
“This is very good news for us. It really opens the door for commercialization,” says plant biologist Caixia Gao at the Chinese Academy of Sciences’ Institute of Genetics and Developmental Biology in Beijing, who is a co-author of the paper.
According to Jin-Soo Kim, who heads the Center for Genome Engineering at the Institute for Basic Science in Daejeon, South Korea, "the decision is a big step forward for China" and will take research from theory into the field.
China's new rules are more conservative than those in the United States, which do not regulate gene-edited crops that incorporate small changes similar to those that might occur naturally, but are more lenient than the European Union's stance of treating all gene-edited crops as genetically modified (GM) organisms.
No foreign genes
CRISPR–Cas9 technologies, which can make minor changes to DNA sequences, are used to develop gene-edited crops. They vary from crops obtained by genetic modification in that the introduction of entire genes or DNA sequences from other plant or animal species is often required. However, until now, they have been subject to the same legislation as GM organisms in China.
Obtaining biosafety approval for a GM crop in China can now take up to six years. However, experts believe that the new guidelines, which outline the process for acquiring a biosafety certificate for gene-edited crops, might cut the approval period to one to two years.
GM crops require extensive, large-scale field trials before they are approved for use. The new guidelines stipulate that, for gene-edited crops deemed to pose no environmental or food-safety risks, developers need only provide laboratory data and conduct small-scale field trials.
However, some of the guidelines, according to the researchers, are vague. They apply to crops where gene-editing technology is used to eliminate genes or make single-nucleotide changes, but it is unclear whether they also apply to crops where DNA sequences from other varieties of the same species have been introduced.
"We will have to confirm whether these are allowed," says Chengcai Chu, a rice geneticist at South China Agricultural University in Guangzhou, because it is essential to have clarity about the guidelines.
Researchers are already planning to focus more of their efforts on generating new crops that will be valuable to farmers. Jian-Kang Zhu, a plant molecular biologist at Shenzhen's Southern University of Science and Technology, for example, says he aims to create gene-edited varieties with increased yields, more resilience against climate change and a better response to fertilizer.
Others are exploring applications for aromatic rice and soya beans with high oleic fatty acid content, which could produce oil low in saturated fats.
Resistance and development
Gao's powdery mildew-resistant wheat might be among the first to receive approval. She and her team used gene editing in 2014 to knock out a gene that makes wheat susceptible to the fungal disease, but they discovered that the modifications also hindered the plant's growth2. One of their edited plants, however, grew properly, and the researchers discovered that this was due to the loss of a portion of chromosome, which meant that the expression of a gene involved in sugar production was not repressed.
Since then, the researchers have been able to remove the same portion of the chromosome, as well as the gene that renders the plant sensitive to powdery mildew, resulting in fungus-resistant wheat cultivars with unrestricted growth.
"This was a very comprehensive and beautifully done piece of work," says Yinong Yang, a plant biologist at Penn State University in University Park. Powdery mildew can infect over 10,000 plant species, he says, so it has broad implications for practically all flowering plants.
"It's incredibly interesting work," says David Jackson, a plant geneticist at Cold Spring Harbor Laboratory in New York, adding that the data on how well the wheat grew were based on a relatively few plants largely grown in greenhouses and will need to be confirmed with larger field trials.
Studies such as this are evidence of China’s strong track record of research into gene-edited crops, and the new regulations “are set to see China take full advantage of their academic lead”, says Penny Hundleby, a plant scientist at the John Innes Centre in Norwich, UK.
