Recently, the Crop Functional Genomics Research Innovation Team of the Institute of Crop Science of the Chinese Academy of Agricultural Sciences revealed a new mechanism for the URL1 gene to regulate the curling of rice leaves through the formation of a transcription repressor complex. On January 13, related research papers were published online in the journal”Plant Physiology”.
According to Li Xueyong, as the main place for photosynthesis of rice, the improvement of its morphology is one of the important goals of rice plant type breeding. Moderate leaf curling is conducive to shaping compact plant type, improving colony structure, increasing photosynthetic efficiency and yield. Although many genes controlling leaf curling have been cloned in rice, the genetic and biochemical relationship of each gene is still unknown. More genes need to be cloned to construct and perfect rice leaf curling molecular regulatory network. In addition, most of the cloned leaf rolling genes were mutated with unfavorable yield traits such as dwarfing and reduced fertility, so they could not be effectively used in breeding.
In this study, a semi-dominant involute leaf mutant Url1 was obtained by mutagenesis of the japonica rice variety Nipponbare. The number and area of alveolar epidermal cells on the leaves decreased, resulting in involute leaves, so the mutant plant type was erect. , But the plant height, ear type, fertility and grain size are not adversely affected, so it is suitable for planting under high density conditions. The researchers isolated the URL1 gene, and further biochemical analysis showed that URL1 participates in the formation of a transcription repressive complex, which directly binds to the promoter of the ACL1 gene, a positive regulator of vesicular cell development, and inhibits its expression, resulting in leaf curling. These results indicate that URL1 plays an important role in the regulation of rice leaf shape. This research is helpful to construct and perfect rice leaf curl molecular regulation network, and has important theoretical and guiding significance for rice plant type breeding.
Fang Jingjing, an assistant researcher at the Institute of Composition, and Guo Tingting, a graduated doctoral student, are the co-first authors of the paper, and researcher Li Xueyong is the corresponding author. The research was funded by the National Major Project for Genetically Modification, the National Natural Science Foundation of China and the Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences.