Dt1基因调控大豆结荚习性的调控通路研究

The stem growth habit of soybean is an important agronomic character. It’s an essential factor that affects plant architecture and yield per plant. It’s reported that stem growth habit changes from indeterminate to determinate in dt1 (tfl1b) mutant lines, moreover, few nodes are produced and productivity is reduced. However, the regulation pathway of soybean Dt1 regulated stem growth habit is not clear. In the previous research, applicant found that FDc1 protein could interact with Dt1 protein by using yeast two hybrid, and the expression patterns of AP1 and LFY homologs were apparently different between NIL-Dt1 SAM and NIL-dt1 SAM. Therefore, stem growth habit might be regulated by Dt1+FDc1 module in soybean. In this research, molecular biology methods will be used to confirm the function of Dt1 interacting protein FDc1, to uncover new genes downstream of Dt1, and to elucidate the regulation pathway of Dt1 regulated stem growth habit. This study will broaden the knowledge of soybean stem growth habit, provide gene resources to soybean molecular design breeding, and improve soybean yield per plant. Both academic and application value will be applied.

结荚习性是大豆重要的农艺性状，是影响大豆株型和单株产量的重要因素。研究表明，大豆结荚习性基因Dt1的突变会导致无限结荚习性转变为有限结荚习性，主茎节数减少，产量降低，但其调控通路尚未明确。申请人前期研究中运用酵母双杂交技术筛选到了Dt1的互作蛋白FDc1，并发现AP1和LFY大豆同源基因在NIL-Dt1生长点的表达模式与NIL-dt1相反，因此推测大豆可能利用Dt1+FDc1模块调控下游基因从而调控结荚习性。本研究拟从分子生物学的角度明确Dt1互作蛋白FDc1的功能，筛选Dt1下游调控基因，阐明Dt1调控大豆结荚习性的调控通路。本研究可以丰富人们对大豆结荚习性的认知，为大豆分子设计育种提供基因资源，为提高大豆单株产量提供重要的思路和途径，具有重要的学术价值和应用价值。

大豆 （Glycine max）是世界范围内重要的粮油作物。大豆营养生长向生殖生长转变的分子机制对于提高大豆产量、高纬度适应性及分子育种具有重要意义。PEBP家族的TERMINAL FLOWER 1 （TFL1）是拟南芥成花转变调控的关键蛋白，具有抑制开花和维持茎顶端无限生长的功能。大豆Dt1基因是TFL1同源基因，调控大豆结荚习性，从而控制大豆单株节数和单株荚数，最终决定大豆的单株产量。但是Dt1是否参与开花期调控及其分子机制尚不明确。本研究发现Dt1除了调控大豆主茎节数和株高以外还参与调控长日照开花期。Dt1通过与bZIP转录因子FDc1互作直接抑制AP1基因的表达，抑制成花转变。AP1在花分生组织表达，通过直接抑制Dt1基因的表达促进花分生组织形成。这样就形成了Dt1/FDc1-AP1-Dt1负反馈抑制环，来精确调控大豆生长点发育的平衡，从而控制大豆节数和荚数和单株产量的形成。这些新发现让我们更深入的认知Dt1在调控大豆结荚习性和开花期中的作用，进而对提高大豆适应性和产量奠定了理论基础。