On July 9, Nature Communications published a research paper by the team of academician Zhang Xianlong of Huazhong Agricultural University online, which revealed the functional differentiation of two homologous genes in cotton, forming two calcium signaling pathways, which are the molecular mechanisms that positively and negatively regulate the drought resistance of cotton, which is the first time in the world.
Nature Communications发表华农张献龙院士团队的研究论文
Cotton is an important cash crop and oil crop. At present, the cotton planting area on the mainland has gradually shifted to arid and high temperature areas, and the main cotton producing areas are concentrated in Xinjiang, with drought and little rainfall. At the same time, the growth period of cotton is long, the peak growth period is in the high temperature season, the transpiration is strong, the water demand is large, and drought stress has become one of the main constraints affecting cotton production. Exploring drought resistance genes, analyzing drought resistance mechanisms, and creating drought-resistant germplasm are important ways to realize drought resistance breeding in cotton.
In the process of polyploid plant evolution, homologous genes are mostly derived from gene replication, which is considered to be an important force in speciation, diversification and adaptability, and plays a very important driving role in the evolution of gene families, which will form the functional differentiation and innovation of regulatory networks. Cotton is a heterotetraploid and has strong adaptability to adversity. Why is this study being conducted? This is because the relationship between the strong adaptability of cotton and its polyploidy was not clear before, how the homologous genes evolved in heteropolyploidy, and the mechanism and regulatory network of the subfunctionalization or neo-functionalization of homologous genes in adapting to drought stress were not clear.
Professor Yang Xiyan of the Cotton Genetic Improvement Team of the National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University
Professor Yang Xiyan of the Cotton Genetic Improvement Team of the National Key Laboratory of Crop Genetic Improvement of Huazhong Agricultural University and Hubei Hongshan Laboratory introduced that the research on the mechanism of calcium signal regulating crop drought resistance has a history of more than 20 years. As a "second messenger", calcium is widely involved in plant development and adaptation to stress, and the activation and conduction of calcium signals are key scientific issues that are of global concern.
"The innovation of our study lies in the discovery of two homologous genes in the process of calcium signaling, which happen to have opposite functions in regulating cotton drought resistance, and one homologous gene negatively regulates cotton drought resistance, and the drought resistance of cotton can be improved by knocking out this gene; Another homologous gene is regulating drought resistance in cotton, and by overexpressing it, i.e., strengthening this gene, the drought resistance of cotton is improved. Yang Xiyan introduced.
Prof. Yang Xiyan and Dr. Sun Weinan are studying seed germination under drought treatment
However, the process of this research is not easy, Huazhong Agricultural University Crop Genetic Improvement National Key Laboratory of Cotton Genetic Improvement Team, Hubei Hongshan Laboratory postdoctoral Sun Weinan is the first author of the paper, he told the Yangtze River Cloud News reporter that if you want to more perfect the positive and negative regulatory mechanism of the two homologous genes in cotton, you first need to get its transgenic materials, and the two signaling pathways involve at least four genes of transgenic materials. It may take one to two years to get each material, and the study of signaling pathways also requires the acquisition of materials with different combinations of hybridization, and further determination of calcium ions and potassium ions when studying its mechanism, which are relatively time-consuming processes.
In the context of global warming, water scarcity is an urgent problem to be solved in cotton production, and important drought resistance genes are not only the core key points of biological breeding, but also one of the core resources of global competition. "On the one hand, the application of this research is to introduce drought resistance into excellent varieties through cross-breeding and auxiliary selection of the obtained transgenic materials; On the other hand, these genes can be developed into functional markers, which can be used to evaluate existing varieties or to assist in the selection of varieties to be reviewed, so as to improve drought resistance. ”
Not only drought resistance, but also cotton yield, quality, other stress resistance and machine harvesting traits can be improved by manipulating important genes. Professor Yang Xiyan believes that the current goal is to achieve the collaborative improvement of multiple traits, and aggregate the key positive regulatory genes that regulate important traits through molecular design and new biological breeding technologies, or knock out the key negative regulatory genes in batches or at the same time, so as to obtain major varieties with simultaneous improvement of multiple traits.
"Our goal is to breed cotton varieties that save more than 20% of water. The application of this research results to the cultivation of cotton and even other grains will have a very good prospect. Yang Xiyan put forward the future goals of the R&D team.
(Changjiang Cloud News reporter Wang Yu, Wang Jiarui, Tan Siwei)