Natural variation in GmGBP1 promoter affects photoperiod control of flowering time and maturity in soybean

First author: Lin Zhao; Affiliations: Northeast Agricultural University (东北农业大学): Harbin, China

Corresponding author: Wenbin Li (李文滨)

The present study screened for polymorphisms in coding and non‐coding regions of the GmGBP1 gene in 278 soybean accessions with variable maturity and growth habit characteristics under natural field conditions in three different latitudes in China. The results showed that the promoter region was highly diversified compared to the coding sequence of GmGBP1. Five polymorphisms and four haplotypes (单倍型) were closely related to soybean flowering time and maturity through association and linkage disequilibrium analyses (连锁不平衡分析). Varieties with the polymorphisms SNP_‐796G, SNP_‐770G, SNP_‐307T, InDel_‐242normal, SNP_353A or haplotypes Hap‐3 and Hap‐4 showed earlier flowering time and maturity in different environments. The shorter growth period might be largely due to the higher GmGBP1 expression levels in soybean, which were caused by the TCT‐motif with SNP_‐796G in the promoter. In contrast, the lower expression level of GmGBP1 in soybean caused by RNAi interference of GmGBP1 resulted in longer growth period under different day lengths. Furthermore, the gene interference of GmGBP1 also caused a reduction in photoperiod response sensitivity (光周期响应灵敏度) before flowering in soybean. RNA‐Seq analysis on the GmGBP1 underexpression in soybean showed that 94 and 30 predicted genes were significantly up‐ and downregulated. Of these, the diurnal photoperiod‐specific expression pattern of three significant flowering time genes GmFT2a, GmFT5a and GmFULc also showed constantly lower mRNA levels in GmGBP1‐i soybean than in wild‐ ype especially in short days. Together, the results showed that GmGBP1 functioned as a positive regulator upstream of GmFT2a, and GmFT5a to activate the expression of GmFULc to promote flowering in short days.

本文对在中国三个不同纬度的自然大田条件下存在成熟与生长性状变异的278份大豆品系进行了GmGBP1基因的编码区及非编码区的多态性的鉴定。结果显示相对于GmGBP1基因编码区，启动子区域的多样性更高。作者通过关联分析和连锁不平衡分析鉴定到了与大豆开花时间及成熟相关的5个多态性和4个单倍型。带有SNP_‐796G、SNP_‐770G、SNP_‐307T、InDel_‐242normal、SNP_353A或者单倍型Hap‐3和Hap‐4的品系在不同的环境下都表现出开花时间更早，成熟更早。大豆更短的生长周期可能是由于更高的GmGBP1基因表达所导致的，而GmGBP1基因启动子区带有SNP_‐796G的TCT基序是增加GmGBP1基因表达的关键。相反，利用RNAi干扰降低GmGBP1基因的表达会降低大豆在未开花期间对于光周期响应的敏感度。对于GmGBP1低表达的大豆的转录组分析鉴定到了94个上调表达基因和30个下调表达基因。这些基因中，GmFT2a、GmFT5a和GmFULc三个具有昼夜特异性表达模式的开花时间相关基因相比于野生型大豆，在GmGBP1基因的RNAi干扰大豆株系中的显示出较低的mRNA水平，尤其是在短日照条件下表现更为明显。综上，本文的结果显示GmGBP1基因作为GmFT2a和GmFT5a的上游正向调控基因，激活GmFULc基因的表达，促进大豆在短日照条件下开花。

通讯：李文滨 (http://nxy.neau.edu.cn/szdw_nei.asp?id=504)

个人简介：1978-1982年，东北农业大学，农学学士；1982-1985年，东北农业大学，农学硕士；1985-1988年，东北农业大学，农学博士。

doi: https://doi.org/10.1111/tpj.14025

Journal: the plant journal

First Published: 13 July, 2018

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