水稻无侧根基因Lrt1的克隆与功能解析

Rice, as an important model monocot plant, absorbs and transports water and nutrients mainly through its lateral roots which exhibit the anatomical structural differences from Arabidopsis. However, in contrast to Arabidopsis, genetic mechanism responsible for the formation of rice lateral roots is not well studied. Our previous studies have isolated a dominant gene, Lrt1, for suppressing lateral roots formation using a map-based cloning approach. Also the transgenic complementary test has validated the gene function. Here, we proposed a series of genetic experiments to characterize and elucidate Lrt1 gene regulatory network for the development of lateral root. The genes which interact or were regulated by Lrt1 will be screened with the technologies of inhibitor screening, yeast two-hybrid screening, Lrt1/lrt2 double mutant construction, RNA-seq, and verified by Pull-down and CoIP. The goals of this proposal are to dissect the Lrt1 regulatory network and the molecular mechanism for lateral root formation mediated by auxin, and to provide useful genetic information for improving the root architecture in the rice breeding efforts.

侧根是植物从土壤中吸收水分和矿物养分的主要器官。水稻作为单子叶禾本科中的重要粮食作物，其根系的形态和结构有别于双子叶模式植物拟南芥。深入分析水稻侧根的发生机理不仅能加深对水稻根系形成的了解，而且为改良水稻的根系结构，从而提高水稻对养分和水分的吸收提供理论依据。本项目以水稻无侧根显性突变体Lrt1为研究材料，通过图位克隆技术分离Lrt1基因，经转基因功能互补进一步确认该候选基因。通过抑制子筛选和酵母双杂交，构建Lrt1/lrt2双突变体，再结合转录组分析以及Pull-Down和CoIP技术验证，鉴别出与Lrt1互作及受之调控的关键因子，绘制出Lrt1基因在生长素参与对水稻侧根发育调控网络中的位置，阐明Lrt1基因控制水稻侧根发育的分子机制，为水稻根系育种提供理论基础。