PDF(Pubmed)
Abstract：
Aluminum (Al) toxicity is one of the environmental stress factors that affects crop growth, development, and productivity. MYB transcription factors play crucial roles in responding to biotic or abiotic stresses. However, the roles of MYB transcription factors in Al tolerance have not been clearly elucidated. Here, we found that GmMYB183, a gene encoding a R2R3 MYB transcription factor, is involved in Al tolerance. Subcellular localization studies revealed that GmMYB183 protein is located in the nucleus, cytoplasm and cell membrane. Overexpression of GmMYB183 in Arabidopsis and soybean hairy roots enhanced plant tolerance towards Al stress compared to the wild type, with higher citrate secretion and less Al accumulation. Furthermore, we showed that GmMYB183 binds the GmMATE75 gene promoter encoding for a plasma-membrane-localized citrate transporter. Through a dual-luciferase reporter system and yeast one hybrid, the GmMYB183 protein was shown to directly activate the transcription of GmMATE75. Furthermore, the expression of GmMATE75 may depend on phosphorylation of Ser36 residues in GmMYB183 and two MYB sites in P3 segment of the GmMATE75 promoter. In conclusion, GmMYB183 conferred Al tolerance by promoting the secretion of citrate, which provides a scientific basis for further elucidating the mechanism of plant Al resistance.
摘要：
铝(Al)毒性是影响作物生长的环境胁迫因子之一,发展,和生产力。MYB转录因子在响应生物或非生物胁迫中起着至关重要的作用。然而,MYB转录因子在铝耐受中的作用尚未明确阐明。这里,我们发现GmMYB183，一个编码R2R3MYB转录因子的基因，涉及铝耐受性。亚细胞定位研究表明，GmMYB183蛋白位于细胞核，细胞质和细胞膜。与野生型相比，GmMYB183在拟南芥和大豆毛状根中的过表达增强了植物对Al胁迫的耐受性，具有较高的柠檬酸盐分泌和较少的铝积累。此外，我们发现GmMYB183与GmMATE75基因启动子结合,该启动子编码质膜定位的柠檬酸盐转运蛋白.通过双荧光素酶报告系统和酵母一个杂种，显示GmMYB183蛋白直接激活GmMATE75的转录。此外，GmMATE75的表达可能取决于GmMYB183中Ser36残基的磷酸化和GmMATE75启动子P3片段中的两个MYB位点。总之,GmMYB183通过促进柠檬酸盐的分泌赋予铝耐受性，为进一步阐明植物抗铝机理提供了科学依据。
