不同生育期组大豆品种开花关键基因GmFT2a及其侧翼序列的多态性研究

Different photoperiod responses of soybean cultivars determine their maturity diversity, but the underlying mechanism is rather unclear. It was reported that photoperiod regulation of the expression of a key flowering gene GmFT2a is apparently different between the photoperiod-sensitive late-maturing cultivar Zigongdongdou and photoperiod-insensitive early-maturing Heihe27, which suggested that the differential photoperiod regulation of GmFT2a might be the important reason which lead to the maturity diversity of cultivars. Here, the polymorphism of GmFT2a and its flanking sequences will be further elucidated in different maturity groups, the expression of GmFT2a under different photoperiods will be also analyzed, and the relationship between the polymorphism of GmFT2a and its flanking sequences and the photoperiod-sensitivity and maturity of cultivars will be deduced. Based on the typical polymorphisms, specific sequences will be selected and fused with a reporter gene GFP to construct fusion expression vectors, which will be transformed into Arabidopsis, and the impact will be analyzed of these specific sequences on the expression of the reporter gene GFP under different photoperiods. Thus, it is expected to learn the relationship between the polymorphism of GmFT2a and its flanking sequences and soybean maturity, understand further the molecular mechanism of soybean photoperiodism, and promote soybean breeding with wide adaptability.

大豆品种光周期反应的差异决定其生育期的多样性，但相关分子机制并不很清楚。前期研究发现，在光周期敏感的晚熟品种自贡冬豆和钝感的早熟品种黑河27中，光周期对开花关键基因GmFT2a的表达调控明显不同，表明在不同品种中受光周期调控的GmFT2a的差异表达可能是造成品种生育期分化的重要原因。本项目拟进一步明确不同生育期组品种中GmFT2a及其侧翼序列的多态性，分析GmFT2a在不同光周期下的表达情况，阐明GmFT2a及其侧翼序列的多态性与品种光周期敏感性和生育期的关系；根据典型多态性类型，挑选特征序列与报告基因GFP融合，构建融合表达载体，在转基因拟南芥中分析这些特征序列如何影响报告基因GFP在光周期下的表达。上述研究结果，将有助于全面了解GmFT2a及其侧翼序列的多态性与生育期多样性的关系，为了解大豆品种生育期差异的分子机制奠定基础，为培育大豆广适应品种提供理论依据。

大豆品种光周期反应的差异决定其生育期的多样性，但相关分子机制并不清楚。本研究以开花调控网络的核心开花信号整合因子Flowering Locus T的同源基因GmFT2a为研究对象，考察GmFT2a基因在不同生育期组大豆中的多态性及其与大豆生育期组多样性的关系，发现GmFT2a尽管在启动子区域存在丰富变异，但是它的一个单元型HT06呈优势分布，涵盖所有生育期组，说明GmFT2a主要是在转录水平上调控大豆光周期反应及生育期的，因此有必要进一步深入研究GmFT2a转录调控的分子机制。为了夯实相关研究基础，需要首先弄清大豆材料遗传背景，特别是关于生育期E基因的遗传背景。为此，本研究通过分析不同生育期组材料的光周期反应特性和生育期性状并鉴定E基因型，发现E基因在生育期性状上具有不同的效应，它们的组合在很大程度上决定了大豆生育期；同时本研究还分析高纬高寒地区大豆材料的生育期性状并鉴定E基因型，发现一个新的比已知最早熟MG000组明显更早熟的生育期组MG0000，并发现部分E基因在高纬高寒地区大豆品种中具有有别于中低纬地区的一些可能与温度相关的特性。相关研究不仅拓宽了生育期组类型，有助于促进大豆高产广适分子育种；同时为今后深入研究GmFT2a转录调控的分子机制提供了基础。