Jilin Province Engineering Laboratory of Plant Genetic Improvement, College of Plant Science, Jilin University, Changchun, China.
Jilin Province Engineering Laboratory of Plant Genetic Improvement, College of Plant Science, Jilin University, Changchun, China.
Plant Physiol Biochem. 2023 Dec;205:108197. doi: 10.1016/j.plaphy.2023.108197. Epub 2023 Nov 17.
Aluminum (Al) toxicity is a major factor limiting crop yields in acid soils. Sweet sorghum (Sorghum bicolor L.) is a high-efficient energy crop widely grown in tropical and subtropical regions of the world, where acid soil is common and Al toxicity is widespread. Here, we characterized a transcription factor SbHY5 in sweet sorghum, which mediated light to promote plant Al stress adaptation. The expression of SbHY5 was induced by Al stress and increasing light intensity. The overexpression of SbHY5 improved Al tolerance in transgenic plants, which was associated with increased citrate secretion and reduced Al content in roots. Meanwhile, SbHY5 was found to localize to the nucleus and displayed transcriptional activity. SbHY5 directly activated the expression of SbMATE, indicating that a HY5-MATE-dependent citrate secretion pathway is involved in Al tolerance in plants. SbSTOP1 was reported as a key transcription factor, regulating several Al tolerance genes. Here, inspiringly, we found that SbHY5 directly promoted the transcription of SbSTOP1, implying the existence of HY5-STOP1-Al tolerance genes-mediated regulatory pathways. Besides, SbHY5 positively regulated its own transcription. Our findings revealed a novel regulatory network in which a light signaling factor, SbHY5, confers Al tolerance in plants by modulating the expression of Al stress response genes.
铝（Al）毒性是酸性土壤中作物产量的主要限制因素。甜高粱（Sorghum bicolor L.）是一种高效能源作物，广泛生长在世界热带和亚热带地区，那里酸性土壤很常见，铝毒性也很普遍。在这里，我们对甜高粱中的一个转录因子 SbHY5 进行了表征，该因子介导了光促进植物对铝胁迫的适应。SbHY5 的表达受铝胁迫和光照强度增加的诱导。SbHY5 的过表达提高了转基因植物的耐铝性，这与柠檬酸分泌增加和根系铝含量减少有关。同时，发现 SbHY5 定位于细胞核并具有转录活性。SbHY5 直接激活 SbMATE 的表达，表明 HY5-MATE 依赖的柠檬酸分泌途径参与了植物的耐铝性。SbSTOP1 被报道为一个关键的转录因子，调节几个耐铝基因。在这里，令人鼓舞的是，我们发现 SbHY5 直接促进了 SbSTOP1 的转录，这表明存在 HY5-STOP1-耐铝基因介导的调控途径。此外，SbHY5 还正向调控自身的转录。我们的研究结果揭示了一个新的调控网络，其中一个光信号因子 SbHY5 通过调节铝胁迫反应基因的表达赋予植物耐铝性。
