Meng Lai-Sheng, Wang Yi-Bo, Loake Gary J, Jiang Ji-Hong
The Key Laboratory of Biotechnology for Medicinal Plant of Jiangsu Province, School of Life Science, Jiangsu Normal UniversityXuzhou, China; Centre for Transformational Biotechnology of Medicinal and Food Plants, Jiangsu Normal University - The University of EdinburghXuzhou, China.
School of Bioengineering and Biotechnology, Tianshui Normal University Tianshui, China.
Front Plant Sci. 2016 Nov 3;7:1645. doi: 10.3389/fpls.2016.01645. eCollection 2016.
In agriculture, seed mass is one of the most important components related to seed yield. () which encodes the transcriptional activator WRKY10, is thought to be a pivotal regulator of seed mass. In SHORT HYPOCOTYL UNDER BLUE1 (SHB1) associates with the promoter of , regulating embryo cell proliferation (both cell division and elongation), which, in turn, modulates seed mass. Furthermore, the recruitment of SHB1 via MINI3 to both its cognate promoter and that of implies a two-step amplification for countering the low expression level of , which is thought to function as a molecular switch for seed cavity enlargement. However, it is largely unknown how embryo cell proliferation, which encompasses both cell division and elongation, is regulated by SHB1 and MINI3 function. Here, we show that a loss of function mutation within the transcriptional coactivator ANGUSTIFOLIA3 (AN3), increases seed mass. Further, AN3 associates with the promoter . Genetic evidence indicates that the absence of MINI3 function suppresses the decrease of cell number observed in mutants by regulating cell division and in turn inhibits increased cell size of the line by controlling cell elongation. Thus, seed embryo development is modulated via an gene cascade. This regulatory model provides a deeper understanding of seed mass regulation, which may in turn lead to increased crop yields.
在农业中，种子重量是与种子产量相关的最重要组成部分之一。编码转录激活因子WRKY10的（此处括号内容原文缺失具体基因名称）被认为是种子重量的关键调节因子。在蓝光下短胚轴1（SHB1）与（此处括号内容原文缺失具体基因名称）的启动子结合，调节胚细胞增殖（包括细胞分裂和伸长），进而调节种子重量。此外，MINI3通过招募SHB1到其同源启动子以及（此处括号内容原文缺失具体基因名称）的启动子，意味着存在一个两步放大过程来应对（此处括号内容原文缺失具体基因名称）的低表达水平，（此处括号内容原文缺失具体基因名称）被认为是种子腔扩大的分子开关。然而，目前尚不清楚包含细胞分裂和伸长的胚细胞增殖是如何由SHB1和MINI3的功能调控的。在这里，我们表明转录共激活因子窄叶3（AN3）功能缺失突变会增加种子重量。此外，AN3与（此处括号内容原文缺失具体基因名称）启动子结合。遗传证据表明，MINI3功能缺失通过调节细胞分裂抑制了（此处括号内容原文缺失具体基因名称）突变体中观察到的细胞数量减少，并通过控制细胞伸长抑制了（此处括号内容原文缺失具体基因名称）品系细胞大小的增加。因此，种子胚发育是通过一个（此处括号内容原文缺失具体基因名称）基因级联来调节的。这种调控模型为种子重量调控提供了更深入的理解，这反过来可能会提高作物产量。
