Wang Nan, Xing Yadi, Lou Qijin, Feng Ping, Liu Song, Zhu Meidan, Yin Wuzhong, Fang Shunran, Lin Yan, Zhang Tianquan, Sang Xianchun, He Guanghua
Key Laboratory of Application and Safety Control of Genetically Modified Crops, Rice Research Institute of Southwest University, Chongqing, 400716, PR China.
Key Laboratory of Application and Safety Control of Genetically Modified Crops, Rice Research Institute of Southwest University, Chongqing, 400716, PR China.
J Plant Physiol. 2017 Feb;209:84-94. doi: 10.1016/j.jplph.2016.11.012. Epub 2016 Dec 7.
Plant hormones coordinate a plant's responses to environmental stimuli and the endogenous developmental programs for cell division and elongation. Brassinosteroids are among the most important of these hormones in plant development. Recently, the ubiquitin-26S-proteasome system was identified to play a key role in hormone biology. In this study, we analyzed the function of a rice (Oryza sativa) gene, DSG1, which encodes a U-box E3 ubiquitin ligase. In the dsg1 mutant (an allelic mutant of tud1), the lengths of the roots, internodes, panicles, and seeds were shorter than that in the wild-type, which was due to defects in cell division and elongation. In addition, the leaves of the dsg1 mutant were wider and curled. The DSG1 protein is nuclear- and cytoplasm-localized and does not show tissue specificity in terms of its expression, which occurs in roots, culms, leaves, sheaths, and spikelets. The dsg1 mutant is less sensitive to brassinosteroid treatment than the wild-type, and DSG1 expression is negatively regulated by brassinosteroids, ethylene, auxin, and salicylic acid. These results demonstrate that DSG1 positively regulates cell division and elongation and may be involved in multiple hormone pathways.
植物激素协调植物对环境刺激的反应以及细胞分裂和伸长的内源性发育程序。油菜素甾醇是这些激素中对植物发育最重要的激素之一。最近，泛素-26S-蛋白酶体系统被确定在激素生物学中起关键作用。在本研究中，我们分析了水稻（Oryza sativa）基因DSG1的功能，该基因编码一种U-box E3泛素连接酶。在dsg1突变体（tud1的等位突变体）中，根、节间、穗和种子的长度比野生型短，这是由于细胞分裂和伸长存在缺陷。此外，dsg1突变体的叶片更宽且卷曲。DSG1蛋白定位于细胞核和细胞质，在表达方面不表现出组织特异性，在根、茎、叶、叶鞘和小穗中均有表达。dsg1突变体对油菜素甾醇处理的敏感性低于野生型，并且DSG1的表达受到油菜素甾醇、乙烯、生长素和水杨酸的负调控。这些结果表明，DSG1正向调节细胞分裂和伸长，可能参与多种激素途径。
