水稻株型遗传调控网络解析

Rice is the staple food for more than half the world’s population. Plant height, tiller number, tiller angle, and panicle architecture are main determinants of rice plant architecture, which affect grain production in the field. Previous studies identified various key genes involved in rice tillering, including MONOCULM 1(MOC1) , Tillering and Dwarf 1(TAD1), LAZY 1(LA1), and DWARF(D), etc. In-depth analysis of these genes revealed that plant height, tiller number, and tiller angle regulate rice plant architecture and production in a coordinative manner. In this project, we are going to dissect the genetic network of the control of rice plant architecture. We will use genetics, biochemical, biological and genomics technologies to identify the genetic network involved in the regulation of plant height, tiller number and tiller angle, as well as their in determining rice plant architecture. Meanwhile, we are going to further elucidate the genetic mechanism of redistribution of water and ions-mediated rice tillering. We are attempting to identify novel major regulators in the control of rice plant architecture and to evaluate their potential in the improvement of grain yields.

水稻是世界上最重要的粮食作物之一，其株型改良是水稻品种选育的核心指标。水稻株型的主要决定因素包括株高、分蘖数目、分蘖角度和穗型。目前已相继克隆了许多调控分蘖发育的关键基因，包括调控分蘖起始的基因MONOCULM 1（MOC1）、调控MOC1蛋白降解的基因Tillering and Dwarf 1（TAD1）、控制分蘖角度的基因LAZY 1（LA1）、以及多个独角金内酯合成和信号途径的关键调控因子DWARF（D）等。对这些基因功能的深入研究表明，分蘖数目、分蘖角度及株高之间并不完全孤立，水稻产量的提高需要它们的协同配合。本项目将在前期研究的基础上，通过遗传学、生物化学、细胞生物学及组学等手段研究分蘖形成与株高协同调控、水稻分蘖角度与分蘖数协同调控的遗传机制及其调控网络，同时研究分蘖与水分、离子营养吸收再分配的遗传关系，旨在挖掘调控株型的主效新基因，从中发现提高产量的可利用的基因资源。

株型改良是水稻品种选育的核心指标，揭示水稻株型的遗传调控网络将为水稻的株型改良提供理论指导和优异基因资源。独脚金内酯在植物株型建成中发挥重要作用，本项目在前期对独脚金内酯信号途径抑制子DWARF 53（D53）和理想株型调控因子Ideal Plant Architecture 1（IPA1）的研究基础上，发现IPA1即是长期寻找的D53的下游转录因子，同时也阐释了独脚金内酯受体蛋白D14的负反馈调控机制，进一步丰富和完善了独脚金内酯信号通路。LAZY1（LA1）是关键的水稻分蘖角度调控基因，我们在深入分析水稻幼苗茎基部的重力反应动态转录组数据后，从中发掘了新的分蘖角度调控节点基因，并揭示了以LA1为核心介导的水稻分蘖角度调控途径。此外，我们还鉴定了调控水稻分蘖发育的离子通道蛋白More Tillering 1（MTI1），为阐明离子营养调控水稻分蘖发育的分子机制提供了契机。本项目的研究成果为深入揭示水稻株型性状间的协同调控机制及株型的遗传调控网络奠定了基础。