水稻侧生小穗形成的遗传调控网络解析

植物的株型主要取决于茎顶端分生组织和侧生分生组织的活力。水稻侧生分生组织的发育决定了分蘖数、穗枝梗数、着粒密度，是产量性状的重要决定因素。本研究基于2个新的控制水稻穗侧生分生组织形成的转录因子为研究对象，建立它们与LAX1和LAX2等侧生小穗分生组织发育基因的互作和调控关系，并进一步发掘与它们互作基因和受它们调控的靶基因，系统建立水稻小穗形成的遗传调控网络；通过分析这些小穗形成基因在生长素合成和极性运输中的功能，探讨生长素与小穗侧生分生组织发育的关系；利用水稻核心种质资源的基因组测序信息，评估水稻小穗形成基因的不同单倍型对产量的贡献。本项目从遗传学、细胞发育生物学和分子生物学方面深入探究水稻穗形态建成的分子机理，为水稻产量性状的遗传改良奠定理论基础。

Plant architecture is dependent on the activity of the shoot apical meristem and axillary meristems. Axillary meristems generate tillers, inflorescence branch, rachis branch and spikelets. Thus, the pattern of axillary meristem formation is of special significance in crop production. In this project, we identified 2 novel transcription factors required for the development of inflorescence axillary meristem in rice. We will study the relationship between them and LAX1 and LAX2, which are involved in the formation of axillary meristem in inflorescence. By identifying the interaction proteins and the target genes of those transcription factors involved in the formation of axillary spikelets, a genetic regulatory network of spikelet formation will be established in rice. Meanwhile, elucidation of the roles of those genes in auxin biosynthesis and polar transport will characterize how the auxin biosynthesis or polar transport influences the formation of axillary spikelets. Furthermore, based on the whole genome re-sequencing of the rice core collection, we will evaluate the contribution of different haplotypes of those genes involved in spikelet formation to yield. Employing genetics, cell biology and molecular biology strategies, this project will preliminarily uncover the molecular mechanism of rice inflorescence architecture and provide the fundamental basis for the yield genetic improvement in rice.