耐低钾大豆品种筛选及低钾胁迫下Lee 68的差异表达基因分析

Screening of Tolerant Soybean Varieties and Analysis of Differential Expressed Genes of Lee 68 Under Low-Potassium Stress

为了从分子水平上研究大豆幼苗对低钾胁迫的耐性机理,本研究首先依据生物量指标从25份大豆材料中筛选出耐低钾品种Lee 68,并对低钾胁迫下大豆Lee 68幼苗进行转录组测序和分析。通过对转录组Solexa/Illumina高通量测序数据的分析,共得到160 211 759个reads,将获得的数据与大豆Williams 82基因组序列比对,比对率达到92.83%以上。比较组LK_VS_CK中差异表达基因为3 521个,其中下调和上调基因分别为2 393和1 128个。GO功能聚类分析显示LK_VS_CK比较组的差异表达基因主要富集于植物的代谢过程、胁迫响应及信号转导;KEGG pathway分析中,LK_VS_CK比较组有390个差异表达基因显著富集在19个pathway途径中,其中富集最为显著的是代谢途径,包括氨基酸代谢、脂肪酸和类脂代谢以及碳水化合物代谢等;COG分类统计结果表明LK_VS_CK比较组除649个差异表达基因具有一般性功能之外,377个基因被划分到转录因子功能类,343个基因被划分到信号转导机制功能中。结合差异表达基因的功能分析及茉莉酸信号转导调控机制,筛选到了茉莉酸信号途径上可能参与钾离子吸收转运过程的8个关键候选基因,分别是Glyma09g08290、Glyma09g33730、Glyma03g32890、Glyma04g39010、Glyma 08g09720、Glyma12g36310、Glyma16g32821、Glyma19g45260。研究结果对深入研究大豆钾胁迫下与钾离子高效吸收相关基因的调控及克隆研究具有重要的参考价值。

In order to study the tolerance mechanism of soybean seedlings to low potassium stress at the molecular level,this study selected the low potassium tolerant variety Lee 68 from 25 soybean materials according to the biomass index firstly, and used Lee 68 as test materials in transcriptome sequencing under low potassium stress.Through the analysis of Solexa/Illumina sequencing data, 160 211 759 reads were obtained. The alignment rate reached more than 92.83% compared with the genome sequence of Williams 82.The total differential expressed genes of LK_VS_CK were 3 521, of which down/up-regulated genes were 2 393/1 128 respectively.The GO functional clustering analysis showed that the differential expressed genes in the LK_VS_CK group were mainly enriched in plant metabolic processes, stress response, and signal transduction. The KEGG pathway analysis showed that there were 390 differential expressed genes in LK_VS_CK group and enriched in 19 pathway approach, especially in the metabolic pathways, including amino acids, fatty acid and lipid metabolism, and carbohydrate metabolism. COG classification statistics showed that in the LK_VS_CK comparison group, beside the 649 differentially expressed genes with general function, 377 genes were classified into the function of transcription, and 343 genes were classified into the function of signal transduction mechanism. Combination the function analysis of differential expressed genes with jasmonic acid signal transduction regulation mechanism, eight key candidate genes were screened as follow: Glyma09 g08290, Glyma09 g33730, Glyma03 g32890, Glyma04 g39010, Glyma08 g09720, Glyma12 g36310, Glyma16 g32821, and Glyma19 g45260, which may participate in the uptake of potassium ion transport process in jasmonic acid signaling pathway. These results provide an important reference for further study on the regulation and cloning of genes related to potassium efficient absorption in soybean under potassium stress.