Wei Xiaoshuang, Kim Won-Seok, Song Bo, Oehrle Nathan W, Liu Shanshan, Krishnan Hari B
Key Laboratory of Soybean Biology at the Chinese Ministry of Education, Northeast Agricultural University, Harbin 150030, China.
Plant Genetics Research, USDA-Agricultural Research Service, Columbia, Missouri 65211, United States.
ACS Omega. 2020 Mar 31;5(14):8065-8075. doi: 10.1021/acsomega.0c00128. eCollection 2020 Apr 14.
Spontaneous and radiation-induced mutants of soybean, despite loss of abundant seed proteins, have been reported to grow and reproduce normally without any apparent physiological abnormalities. Here, we report the development and characterization of a soybean line (BSH-2) that lacks several abundant seed storage proteins. One-dimensional and high-resolution two-dimensional gel electrophoresis revealed the absence of the α' and α subunits of β-conglycinin and G1, G2, G4, and G5 glycinin in the newly developed mutant line (BSH-2). Like our earlier developed soybean mutant line (BSH-3), the seeds of BSH-2 also accumulated high levels of free amino acids as compared with wild-type DN47 seeds. An examination of the germination rates revealed that both BSH-2 and BSH-3 had significantly lower germination rates compared with the parent line DN47. Two-dimensional gel electrophoresis analysis demonstrated that these mutants had slower rates of mobilization of seed storage proteins. The delayed mobilization of storage proteins in BSH-2 and BSH-3 seeds was also correlated with a delayed induction of proteolytic activity in the mutants when compared to DN47. Similarly, qRT-PCR analysis revealed distinct expression pattern of genes involved in proteolytic pathway in the mutants when compared to DN47. Transmission electron microscopy observation of soybean seeds at two germination stages revealed striking differences in the breakdown of protein storage vacuoles and lipid bodies in the mutants. Our study demonstrates that BSH-2 and BSH-3 are compromised in mobilization of storage reserves and the absence of abundant storage proteins may affect the seed germination efficiency and post-germinative seedling establishment.
据报道，大豆的自发突变体和辐射诱导突变体，尽管缺失了大量种子蛋白，但仍能正常生长和繁殖，没有任何明显的生理异常。在此，我们报告了一个缺乏几种丰富种子贮藏蛋白的大豆品系（BSH - 2）的培育和特性。一维和高分辨率二维凝胶电泳显示，新培育的突变品系（BSH - 2）中缺乏β-伴大豆球蛋白的α'和α亚基以及11S大豆球蛋白的G1、G2、G4和G5亚基。与我们早期培育的大豆突变品系（BSH - 3）一样，与野生型DN47种子相比，BSH - 2的种子也积累了高水平的游离氨基酸。对发芽率的检测表明，与亲本品系DN47相比，BSH - 2和BSH - 3的发芽率均显著降低。二维凝胶电泳分析表明，这些突变体种子贮藏蛋白的动员速率较慢。与DN47相比，BSH - 2和BSH - 3种子中贮藏蛋白的延迟动员也与突变体中蛋白水解活性的延迟诱导相关。同样，qRT - PCR分析显示，与DN47相比，突变体中参与蛋白水解途径的基因具有不同的表达模式。对两个发芽阶段的大豆种子进行透射电子显微镜观察，发现突变体中蛋白质贮藏液泡和脂体的分解存在显著差异。我们的研究表明，BSH - 2和BSH - 3在贮藏物质的动员方面存在缺陷，大量贮藏蛋白的缺失可能会影响种子发芽效率和发芽后幼苗的建立。
