"All-chain" innovation boosts the citrus industry

Deng Xiuxin (first from right) examines the growth of citrus carefully.Editor's Note
National Natural Science Foundation Innovation Research Group Project aims to support outstanding young and middle-aged scientists to jointly carry out innovative research around an important research direction, and to train and create research groups with a place in the forefront of international science.
years, with the support of such projects, a group of scientists have grown into academic leaders and research backbones, achieving a number of frontier areas from "following" to "leading" and "leading". Among them, in the field of life sciences, Shu Hongbing, a member of the Chinese Academy of Sciences, and Deng Xiuxin, a member of the Chinese Academy of Engineering, led two teams, both of which have received funding for three consecutive innovative research group projects, and have achieved great results in their respective fields. This edition of the Fund focuses on the above two scientific research teams to showcase their scientific research work."Why are some oranges green in the south, the more north they are red? To get the color of the citrus through, you can cite one to three. Deng Xiuxin, vice president of the Chinese Academy of Engineering and a member of the Chinese Academy of Engineering, said in an interview with the China Science Daily on August 2.
He picked up a papaya-shaped orange from his desk, "which was picked in April this year in Nujiang, Yunnan Province, and in the north, its color will become more and more red, stimulated by the lower temperature."
as the only academician in the existing team selected for the study of citrus field, Deng Xiuxin is known as "citrus academician". He led the National Natural Science Foundation of China innovation research group project after 9 years, continuous 3 phases, to solve a number of key issues in China's citrus industry, covering basic research to industry this innovation "whole chain."
" scientific research results to heaven, but also to enter the ground. Deng Xiuxin stressed.to buy fresh fruit, to see the color to distinguish between good and bad is the most commonly used law. What is the mechanism of fruit color formation? In Deng Xiuxin's view, this kind of problems from life is the most worthy of study.
" and in the basic life sciences, such problems cannot be fully covered. Based on this consideration, Deng Xiuxin led the team to obtain funding from the National Natural Science Foundation of China's Innovative Research Group Project. From the beginning of the first phase of the project in 2010 to the conclusion of the third phase of the project in 2018, they focused more closely and focused on actual production on the theme of "Research and genetic improvement of horticultural crop quality resources".
nine years, Deng Xiuxin's new team has been given "four ones": a set of techniques, a new road, a map and a special genetic material.
"set of techniques" is the method of regulating the color of citrus skins. This technique begins with the discovery of key genes and extends to market applications.
, who is also known as a "citrus academician", is a common thing to run to different citrus-producing areas. Collecting citrus species resources in various parts of the South is a compulsory course for Deng Xiuxin's new team. The citrus collected from all over the place corresponded to its color, and the team found that the farther north the site, the reddening of the peel color. Oranges born in the south tend to have higher sugar content and better aromas, although they "sell poorly".
gorgeous and fragrant, just the same is enough? After years of exploring this question, the team found that citrus color changes were associated with the expression regulation of key genes such as PSY, LCYB2 and CCD4b.
history, citrus has been grown northwards or in cold (migration) areas, where DNA insertion occurs in these gene promoter regions, showing sensitivity to low temperatures or adversity. For example, when autumn comes, the temperature drop induces the expression of the CCD4b gene in the peel, and the carotenoids in the peel degrade to de-complementary carotenoids, the lime usin, and the peel turns crimson.
In the researchers' view, by figuring out the mechanism of citrus color formation, the original orange-yellow skin could be turned orange-red by changing temperature, adversity treatment, or artificially giving adversity signals, such as ethylene treatment.
these new understandings, combined with the genetic characteristics of the species, the research team developed a precocious umbilical orange fruit surface red biological color-promoting technology. Now this technology has been demonstrated in the southern umbilical orange production area, umbilical orange by biological means induced, the original blue-yellow orange only takes 5 days to turn orange. Both precocious and gorgeous characteristics, fruit farmers planted precocious oranges also have a good selling phase, due to the early listing, the price is better.
"a new way" among the "4 ones" in the world, is also closely followed by the birth of market demand. In 2015, the first international "Hua grapefruit 2" citrus varieties directly cultivated through cell fusion were born, relying on Deng Xiuxin's team's "one-door life": cell engineering technology. Without changing the other traits of the target variety, they can create a new seedless variety only by transferring the cytostyte containing CMS in Wenzhou honey citrus.
fact, cell engineering has always been Deng Xiuxin's team's strength. As early as Deng Xiuxin's Ph.D., he conquered citrus protophyte culture and plant regeneration technology. China thus became the third country in the world, after Israel and Japan, to receive a regenerative plant of citrus progena.
Guo Wenwu, a professor and team member at the School of Horticultural Forecology at Huahua Central Agricultural University, told China Science that cell engineering was born before molecular biology, and that after the latter came out, the research team did not give up this research direction, and eventually succeeded in transferring the sterubic cytostytes of citrus males through cell fusion to produce non-nuclear varieties.Thanks to more than 30 years of cell engineering research, the research team created the DH (double diploid) system of sweet orange in a short period of time and sequenced the sweet orange genome in less than a year, which is the first fruit tree genome sequencing map independently completed by Chinese researchers, that is, the innovation group research project "four one" in the "one map."
the sweet orange genome sequencing, the team built a comprehensive analysis platform for the citrus genome, the results of which are open to peers around the world. Today, this platform has become an important platform for basic citrus research in the world.
In addition, Xu Qiang, a professor and team member of the School of Horticultural Forecology at Huahua Agricultural University, together with his team, analyzed the molecular mechanism of citrus "multi-embryo" by means of comparative genomics and genetics, and found the key gene CitRWP, which is the first functional gene discovered in the citrus world through positive genetics.
the last of the "four ones" refers to "a genetic material" - single-embryo mountain citrus.
people have only found the multi-embryo varieties of the mountain citrus, hybridization is difficult to get hybrid offspring. Single-embryo mountain gold citrus from the natural mutation of multi-embryo varieties, sowing the year can blossom results, has been looking for precious materials. With it, researchers no longer have to worry about citrus results that are too long and that hybridization doesn't get hybrids.
2000, Deng Xiuxin often went to citrus-producing areas all over the country to help fruit farmers to attract varieties, do training, and Fujian, a local fruit tree station director has a deep friendship. Fruit tree station director learned that Deng Xiuxin team has been looking for a rare mountain gold citrus, then launched the vast number of folks, the mountain may find wild citrus materials sent to Huahua Agricultural University.
, the team found the target among hundreds of citrus materials sent from Fujian. Later, they found a single-embryo mountain gold citrus in a local ravine. This means that the horticultural community's "peach three li four citrus eight years" common sense was broken, many genetic research has since become possible.as a researcher who had won the Youth Science Foundation project in 1988, Deng Xiuxin "came out" earlier. In his view, it was important to have access to funding for the Natural Science Foundation project. "It's not just about funding the team, it's about giving us an opportunity to study different issues and get to the forefront of the world." He said.
, a group of talents is also growing with the project. Deng Xiuxin admitted that the scientific research of single-man combat is outdated, "to consider whether we can pool a force to solve the key problems in the discipline."
the difficulties of citrus research, Deng Xiuxin team has a complete team of scientists. Following "after 60" leader Deng Xiuxin, there are Guo Wenwu, Xu Qiang and other "after 70" and "after 80" composed of the backbone.
"Our team is inclusive and has a clear division of labor." Cheng Yunjiang, a team member and professor at the School of Horticultural Foreculture at Central China Agricultural University, told China Science Daily that everyone here, regardless of their seniority, has the opportunity to fully explore the problem. Mr. Deng often says that good students are encouraged. Cheng Yunjiang said.
years, Deng Xiuxin has its own "Citrus Book": good out of production, adversity to promote quality. "That's what scientific research is all about." He said.
the same direction for many years, the research team is in a variety of "adversity" growth and expansion, to promote the development of China's horticulture disciplines. Since the construction of citrus genome platform and DNA fingerprint database, a large number of molecular biology research results in recent years have been born in the hands of Chinese scholars. "The foundation is that we're playing and it's going to have a big impact on what's going on," he said. Deng Xiuxin said.
theory with practice, practice to promote theoretical research, this is Deng Xiuxin team's simple "research book." In the future, the team will continue to focus on the genetic improvement and regulation of citrus quality, the molecular mechanisms at the forefront of the foundation, and the application research that is beneficial to the industry, so as to promote the continuous development of the citrus industry in the innovation chain.