Dong Huan, Bai Ling, Chang Jie, Song Chun-Peng
Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, 85 Minglun Street, Kaifeng 475001, China.
Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, 85 Minglun Street, Kaifeng 475001, China.
Biochem Biophys Res Commun. 2018 Jan 1;495(1):280-285. doi: 10.1016/j.bbrc.2017.10.113. Epub 2017 Oct 31.
The plant hormone abscisic acid (ABA) plays a crucial role in root architecture; however, the molecular mechanism of ABA-regulated lateral root (LR) growth is not well known. We screened an Arabidopsis thaliana mutant with LR growth that was sensitive to ABA from a T-DNA insertion mutant library, which was an allelic mutant of plgg1-1, termed plgg1-2. PLGG1 encodes a chloroplast protein that transports plastidic glycolate and glycerate. The length and number of LRs at the root-hypocotyl junction of plgg1-1 and plgg1-2 were significantly impaired under exogenous ABA treatment, and the transgenic plant complementary lines of plgg1-2 restored LR growth in response to ABA. In addition, we found that PLGG1 is involved in other major ABA responses, including ABA-inhibited seed germination, ABA-mediated stomatal movement, and drought tolerance. These findings open new perspectives on elucidating the mechanism of ABA response, and provide clues for analysing the functions of chloroplast proteins in regulating root growth.
植物激素脱落酸（ABA）在根系结构中起着关键作用；然而，ABA调节侧根（LR）生长的分子机制尚不清楚。我们从一个T-DNA插入突变体文库中筛选出一个对ABA敏感的LR生长拟南芥突变体，它是plgg1-1的等位突变体，命名为plgg1-2。PLGG1编码一种叶绿体蛋白，负责转运质体乙醇酸和甘油酸。在外源ABA处理下，plgg1-1和plgg1-2根-下胚轴连接处的LR长度和数量显著受损，plgg1-2的转基因植物互补系恢复了对ABA的LR生长响应。此外，我们发现PLGG1参与其他主要的ABA反应，包括ABA抑制种子萌发、ABA介导的气孔运动和耐旱性。这些发现为阐明ABA反应机制开辟了新的视角，并为分析叶绿体蛋白在调节根系生长中的功能提供了线索。
