Academician Li Jiayang: The needs of the country are rooted in the depths of my mind

Text | "China Science News" reporter Feng Lifei

Food security is an important foundation of national security. How to feed 20% of the world's population with 8% of the world's arable land? Seeds are the "chips" of agriculture, and breeding innovation is an important guarantee for food security.

With the research on "molecular mechanism and variety design of the formation of high-yield and high-quality traits in rice", the team of Li Jiayang, academician of the Chinese Academy of Sciences and researcher of the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences (hereinafter referred to as the Institute of Genetics and Development), won the first prize of the 2017 National Natural Science Award. This highest award in the field of natural sciences in China is the best portrayal of the team's original aspiration and mission for more than ten years, and its vow to plant a good rice for the motherland.

This year is the 30th year of Li Jiayang's return to China from studying in the United States, during which he has always been at the forefront of plant genetics research and innovation in mainland China, taking the lead in establishing a molecular genetics research system for the model plant Arabidopsis thaliana in China, taking the lead in isolating the functional genes of the staple crop rice by map cloning, and proposing the concept of molecular design breeding in China. He led the team from basic research to field breeding, and "accurately designed" a series of new nationally approved rice varieties for different rice regions in the mainland, and sowed them on the land of the motherland.

Talking about the source of insisting on innovation, Li Jiayang recently said bluntly in an interview with China Science News: "The driving force of national demand is rooted in the depths of my mind. ”

Li Jiayang inspected the growth of double-cropping early japonica rice in Shanggao County, Jiangxi Province. Feng Lifei/photo

A dream that supports the confidence to face difficulties

Li Jiayang was born into a peasant family in Feixi County, Anhui Province, and when he graduated from high school, ten years of turmoil had not yet ended. He worked as an apprentice on a construction site, moving bricks, digging foundations, and carrying cement during the day, and reading books at night in dimly lit and noisy dormitories. With this "drilling" energy, he took the "first train" of China's resumption of the college entrance examination in 1977 and was admitted to Anhui Agricultural College (the predecessor of Anhui Agricultural University).

In 1981, he was admitted to the Institute of Genetics of the Chinese Academy of Sciences (the predecessor of the Institute of Genetics and Development) as a master's student. In the process of following his mentor researcher Li Jigeng to do cytoplasmic sterility research, Li Jiayang gradually established a dream - to master the most advanced knowledge, cultivate high-yield and high-quality crops, and let the people eat well and well.

In 1985, Li Jiayang went to the United States to study for a doctorate at Brandeis University. In 1991, when choosing a postdoctoral direction, two professors from the Department of Chemistry and the School of Medicine of Harvard University in the United States threw an "olive branch" to him, but the dream in his heart made him resist the temptation of a "famous university" and chose to engage in postdoctoral research in plant molecular genetics at Cornell University in the United States.

Before Li Jiayang returned to China, many people around him advised him to think carefully, because China's scientific research foundation was weak at that time, and he might not be able to keep up with the development of the world's most cutting-edge research after returning to China.

But he didn't hesitate. In 1994, Li Jiayang returned to Beijing and embarked on a long-awaited journey to pursue his dreams.

After returning to the Institute of Genetics and Development, Li Jiayang started from scratch in an old laboratory of more than 30 square meters. Lacking funds and equipment, he and his research team used old test benches and obsolete instruments and equipment used by others.

To realize his dream under such conditions, Li Jiayang is ready to "fight a protracted war".

At the beginning, in order to let the research group "survive", he set the goal of focusing on the model plant Arabidopsis thaliana, which has a short research cycle, and hoped to establish a molecular genetics research system in China. "At that time, the Institute of Genetics and Development, and even the whole of China, a lot of research was rushed to produce a variety, and there was little analysis of the molecular genetic mechanism behind it, and there was relatively large room for innovation in this area." Li Jiayang recalled.

Soon, Li Jiayang's project was formed as the first team in China to allow Arabidopsis thaliana to germinate, flower, and set seeds in the laboratory. Based on this, with the support of the National Science Foundation for Distinguished Young Scholars and other projects, he led the research group to tackle the two most cutting-edge technologies of molecular genetics research at that time, namely gene map cloning technology and gene site-directed integration technology.

Among them, they have achieved great success in the research of map cloning technology. In 2000, Li Jiayang led a research group to find a needle in a haystack from more than 20,000 genes in Arabidopsis thaliana, and used map cloning to isolate the genes that cause cell death and explain the mechanism behind them. This is the first time that mainland scientists have used the map cloning method to isolate a functional gene of higher organisms from many genes, laying the foundation for mainland gene map cloning.

This study also provides a technical route for Li Jiayang to carry out gene cloning in rice breeding.

One idea, a revolution in breeding

Arabidopsis research is only a short-term goal, and Li Jiayang has never let go of the original intention of using what he has learned to increase crop yields and ensure national food security. In 1997, just after the laboratory was stabilized, he decided to study the continent's most important food crop, rice.

At that time, Li Jiayang usually came home from the lab after 11 p.m. In the lab, he often met Dr. Qian Qian of the China Rice Research Institute, who was doing rice research in the laboratory of Zhu Lihuang, a researcher at the Institute of Genetics and Development. The two often discuss together how to carry out rice genetics and breeding, and as the discussion deepens, their ideas become clearer and clearer. "The most important trait of rice is yield, and the most difficult of yield traits is the study of the mechanism of tillering regulation, so we decided to start with rice tillering." Li Jiayang said.

After 7 years of research, they cloned MOC1, a key gene that regulates rice tillering, through map cloning technology. At that time, agricultural scientists generally believed that rice tillering was determined by a complex genetic network, and the discovery of this single gene regulatory model became a milestone in the development of functional genomics of mainland rice, allowing the research of functional genomes of mainland rice to enter a period of rapid development. The research was published in Nature in 2003 and was selected as one of the top ten scientific and technological progress news in China of the year, and also won the second prize of the National Natural Science Award in 2005.

After achieving a breakthrough of "from 0 to 1", Li Jiayang continued to lead the team members to clone a series of important genes that affect the number of rice tillers, plant height, tillering angle, panicle size, panicle type, stem strength and other plant characteristics. More importantly, they discovered IPA1, a key gene for the formation of ideal plant type, and analyzed the molecular mechanism and regulatory network of IPA1-mediated plant type development.

The cloning and functional analysis of these key genes, as well as the rapid development of modern life science technologies such as genome sequencing technology and bioinformation technology, have brought opportunities for the analysis of genetic regulatory networks for complex traits in organisms, and also brought new hope for the innovation of breeding technology.

At that time, conventional breeding in mainland China was experiencing a development bottleneck. Breeders do not know which gene controls which trait when selecting parents, and can only rely on experience to breed new varieties through generations of crossbreeding. Not only does this result in longer breeding cycles, often taking 8 to 10 years, but also narrow and inefficient genetic diversity between breeds, making it increasingly difficult to select breakthrough varieties.

In this context, Li Jiayang put forward the concept of "molecular design" breeding: "Like designing industrial products, by 'assembling' high-yield, disease-resistant, and high-quality gene modules, we can 'design' ideal seeds." ”

The proposal of this new concept has pushed China's breeding technology concept to the forefront of the world.

In August 2013, the Chinese Academy of Sciences Strategic Priority Science and Technology Special Project (Class A) "Molecular Module Design Breeding Innovation System" was launched. Through 4 projects, 12 topics, 64 sub-topics and 144 task topics, more than 2,100 scientists have tried to use this new scientific and technological means to set off a breeding revolution.

After five years of research, the project has made a number of important achievements in germplasm resource mining, design variety cultivation and general technology research and development, etc., creating a molecular module design breeding technology system, creating 200 new strains of rice, soybean, wheat and carp, and approving 27 new varieties, which have been widely promoted in the main producing areas.

A number of new rice varieties "precisely designed" by Li Jiayang have been sown in tens of millions of acres of rice fields in the mainland.

In the middle and lower reaches of the Yangtze River, they cultivated the "Jiayou Zhongke" series of ultra-high-yielding, early-maturing, riceblast-resistant indica-japonica hybrid rice, with a yield of 900 kg per mu, which is more than 20% higher than that of the local main varieties.

In the Northeast Rice Region, the "Zhongkefa 804" and "Zhongkefa" series varieties they cultivated have high yield, good taste, high rice yield, high resistance to lodging and rice blast, of which the cumulative planting area of "Zhongkefa No. 5" alone has reached more than 20 million mu.

From basic theoretical research to the transformation and implementation of achievements, molecular module design breeding has promoted the leapfrog development of mainland breeding technology and provided scientific and technological support for ensuring mainland food security.

In 2017, Li Jiayang and his collaborators won the first prize of the National Natural Science Award for their "Molecular Mechanism and Variety Design for the Formation of High-yield and High-quality Traits in Rice".

Academician Li Zhensheng, winner of the highest national science and technology award, commented that this is the third major breakthrough after the "green revolution" of rice dwarfing and hybrid rice, marking the beginning of the "new green revolution".

A seed, compose a lifelong goal

Over the past 30 years, Li Jiayang has led the team to win a number of heavy honors. In addition to the two National Natural Science Awards, their achievements have also been selected as "China's Top Ten Scientific Progresses" and "China's Top Ten Scientific and Technological Progress News" for 6 times.

Li Jiayang himself has also won the Outstanding Scientific and Technological Achievement Award of the Chinese Academy of Sciences, the Future Science Award, the Chen Kah Kee Science Award and other scientific and technological awards, and has won many honorary titles such as academician of the Chinese Academy of Sciences, foreign academician of the American Academy of Sciences, and academician of the German Academy of Sciences.

"Good fortune never befalls a person for no reason." Han Bin, Li Jiayang's "old partner" and academician of the Chinese Academy of Sciences, said for example that Li Jiayang is one of the best in the world in the study of rice plant types, because he has spent a lot of energy to study almost all rice plant types in the world.

Today, he continues to innovate in the rice fields. "There are five main rice-producing areas on the mainland, four of which are strategic areas. At least in my mind, there are 4 rice areas that must consider the layout of new varieties. Li Jiayang told China Science News.

Due to the different climate and soil conditions in each rice region, Li Jiayang plans to cultivate different excellent new rice varieties from the middle and lower reaches of the Yangtze River to the northeast, and then to central and southern China.

Since 2020, he has led the team to fill the breeding gap, bred a number of new double-cropping early japonica rice strains in the middle and lower reaches of the Yangtze River, achieved a "zero breakthrough" in the mainland's early japonica rice, and promoted the establishment of the mainland's first early japonica rice approval standard, which is expected to allow the Chinese people to eat delicious new japonica rice one quarter in advance.

Now, as the director of Yazhouwan National Laboratory, Li Jiayang is constantly "recruiting" and forming a talent team to promote the construction and development of this national seed science and technology research and seed industry innovation platform as soon as possible; On the one hand, we insist on carrying out research on breeding science and technology.

"I believe that as long as we continue to work hard and immerse ourselves in hard work, our scientific and technological research will be like a seed, breaking through the soil and sprouting, jointing and growing, and finally giving birth to fruitful fruits and contributing to food security and the prosperity of farmers." Li Jiayang said.

"To do scientific research, we must have a lofty goal, which is higher than 'finding a job and making a job', and it is also higher than the pursuit of social identity and status." He encouraged young scientists to dare to tackle and eventually overcome the most challenging problems, combine their personal pursuits with the needs of the country, and create their own history and that of this era.