Jilin Province Engineering Laboratory of Plant Genetic Improvement, College of Plant Science, Jilin University, Changchun 130062, China.
Int J Mol Sci. 2023 Jun 17;24(12):10288. doi: 10.3390/ijms241210288.
Aluminum (Al) toxicity is a primary limiting factor for crop production in acidic soils. The WRKY transcription factors play important roles in regulating plant growth and stress resistance. In this study, we identified and characterized two WRKY transcription factors, SbWRKY22 and SbWRKY65, in sweet sorghum ( L.). Al induced the transcription of and SbWRKY65 in the root apices of sweet sorghum. These two WRKY proteins were localized in the nucleus and exhibited transcriptional activity. SbWRKY22 showed the significant transcriptional regulation of , , , , and , which are major known Al tolerance genes in sorghum. Interestingly, SbWRKY65 had almost no effect on the aforementioned genes, but it significantly regulated the transcription of . Therefore, it is speculated that SbWRKY65 might indirectly regulate Al-tolerance genes mediated by SbWRKY22. The heterologous expression of and greatly improved the Al tolerance of transgenic plants. The enhanced Al tolerance phenotype of transgenic plants is associated with reduced callose deposition in their roots. These findings suggest the existence of SbWRKY22- and SbWRKY65-mediated Al tolerance regulation pathways in sweet sorghum. This study extends our understanding of the complex regulatory mechanisms of WRKY transcription factors in response to Al toxicity.
铝（Al）毒性是酸性土壤中作物生产的主要限制因素。WRKY 转录因子在调节植物生长和抗逆性方面发挥着重要作用。本研究在甜高粱（ L.）中鉴定和表征了两个 WRKY 转录因子 SbWRKY22 和 SbWRKY65。Al 诱导甜高粱根尖中 和 SbWRKY65 的转录。这两个 WRKY 蛋白定位于细胞核内，并表现出转录活性。SbWRKY22 对 、 、 、 、 和等主要已知高粱耐铝基因表现出显著的转录调控作用。有趣的是，SbWRKY65 对上述基因几乎没有影响，但它显著调节 的转录。因此，推测 SbWRKY65 可能通过 SbWRKY22 间接调节耐铝基因。 和 的异源表达大大提高了转基因植物的耐铝性。转基因植物增强的耐铝表型与根中几丁质沉积减少有关。这些发现表明，在甜高粱中存在 SbWRKY22 和 SbWRKY65 介导的耐铝调节途径。本研究扩展了我们对 WRKY 转录因子对 Al 毒性响应的复杂调控机制的理解。
