State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Institute of Soil Science, University of Chinese Academy of Sciences, Beijing 100049, China.
Plant Physiol. 2024 Sep 2;196(1):564-578. doi: 10.1093/plphys/kiae281.
The transcriptional regulation of aluminum (Al) tolerance in plants is largely unknown, although Al toxicity restricts agricultural yields in acidic soils. Here, we identified a NAM, ATAF1/2, and cup-shaped cotyledon 2 (NAC) transcription factor that participates in Al tolerance in Arabidopsis (Arabidopsis thaliana). Al substantially induced the transcript and protein levels of ANAC070, and loss-of-function mutants showed remarkably increased Al sensitivity, implying a beneficial role of ANAC070 in plant tolerance to Al toxicity. Further investigation revealed that more Al accumulated in the roots of anac070 mutants, especially in root cell walls, accompanied by a higher hemicellulose and xyloglucan level, implying a possible interaction between ANAC070 and genes that encode proteins responsible for the modification of xyloglucan, including xyloglucan endo-transglycosylase/hydrolase (XTH) or ANAC017. Yeast 1-hybrid analysis revealed a potential interaction between ANAC070 and ANAC017, but not for other XTHs. Furthermore, dual-luciferase reporter assay, RT-qPCR, and GUS analysis revealed that ANAC070 could directly repress the transcript levels of ANAC017, and knockout of ANAC017 in the anac070 mutant partially restored its Al sensitivity phenotype, indicating that ANAC070 contributes to Al tolerance mechanisms other than suppression of ANAC017 expression. Further analysis revealed that the core transcription factor SENSITIVE TO PROTON RHIZOTOXICITY 1 (STOP1) and its target genes, which control Al tolerance in Arabidopsis, may also be involved in ANAC070-regulated Al tolerance. In summary, we identified a transcription factor, ANAC070, that represses the ANAC017-XTH31 module to regulate Al tolerance in Arabidopsis.
植物对铝（Al）耐受性的转录调控在很大程度上尚不清楚，尽管 Al 毒性会限制酸性土壤中的农业产量。在这里，我们鉴定了一个 NAM、ATAF1/2 和杯状子叶 2（NAC）转录因子，该因子参与拟南芥（Arabidopsis thaliana）的 Al 耐受性。Al 显著诱导了 ANAC070 的转录和蛋白水平，功能丧失突变体表现出明显增加的 Al 敏感性，这表明 ANAC070 在植物耐受 Al 毒性方面具有有益作用。进一步的研究表明，anac070 突变体的根中积累了更多的 Al，特别是在根细胞壁中，同时半纤维素和木葡聚糖水平更高，这表明 ANAC070 可能与编码负责修饰木葡聚糖的蛋白质的基因之间存在相互作用，包括木葡聚糖内切糖基转移酶/水解酶（XTH）或 ANAC017。酵母 1-杂交分析显示 ANAC070 与 ANAC017 之间存在潜在的相互作用，但与其他 XTH 没有。此外，双荧光素酶报告基因分析、RT-qPCR 和 GUS 分析表明，ANAC070 可以直接抑制 ANAC017 的转录水平，并且在 anac070 突变体中敲除 ANAC017 部分恢复了其 Al 敏感性表型，表明 ANAC070 除了抑制 ANAC017 的表达外，还参与了 Al 耐受性机制。进一步的分析表明，核心转录因子 SENSITIVE TO PROTON RHIZOTOXICITY 1（STOP1）及其靶基因可能也参与了 ANAC070 调节的 Al 耐受性。总之，我们鉴定了一个转录因子 ANAC070，它抑制 ANAC017-XTH31 模块来调节拟南芥的 Al 耐受性。
