During the seed maturity period, if crops cannot be harvested in time in case of continuous rain, some seeds will germinate on the ears. Pre harvest sprouting seriously affects crop yield and quality. Chinese scientists have found a pair of "switches" to regulate rice and wheat pre harvest sprouting, which is expected to provide solutions to avoid large-scale agricultural losses caused by pre harvest sprouting. The research was completed by the research team of Chu Chengcai and the research team of Gao Caixia from the Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and the relevant results were published online in the international academic journal Nature Genetics on the 6th. "Seed dormancy refers to the phenomenon that a seed cannot germinate even when it is suitable for its growth. However, in the process of crop domestication, due to more consideration of such traits as high yield, high quality, disease resistance and insect pests, the retention of the moderate dormancy of the seed is often ignored, which leads to the emergence of sprouting in many crops, such as rice and wheat." Chu Chengcai introduced that it is very important to find the key genes that control seed dormancy in crops and clarify the molecular physiological mechanism of seed dormancy regulation to avoid the disaster of pre harvest germination. However, seed dormancy is an extremely complex agronomic trait, which is regulated by a large number of gene loci. The Chu Chengcai team successfully cloned a key gene SD6 that controls rice seed dormancy from a strong dormant rice variety by using the strong dormancy rice variety "Kassalas" and the weak dormancy rice variety "Nihon Qing" to construct a single segment substitution line, and confirmed that SD6 negatively regulates rice seed dormancy. By screening SD6 interacting proteins, the team found another rice transcription factor, ICE2, which is regulating seed dormancy. Chu Chengcai's team improved the SD6 gene in the rice varieties "Tianlong 619", "Wuyunjing 27" and "Huaidao 5" that are easy to sprout by gene editing technology, and found that the improved rice materials suffered continuous rainy weather during the harvest period, and their sprouting conditions were significantly improved. Gao Caixia's team improved the TaSD6 gene of wheat variety "Kenong 199", which also greatly improved the resistance of wheat to pre harvest sprouting. "These research results show that SD6 has important application value in breeding and improvement of rice and wheat resistance to pre harvest sprouting. SD6 and ICE2 genes are expected to play an important role in solving the problem of pre harvest sprouting and reducing agricultural losses." Gao Caixia said. (Outlook New Times)