Department of Botany, Guwahati College, Assam, 781021, India.
Department of Entomology, Agricultural Research Organization, The Volcani Institute, 7505101, Rishon LeZion, Israel.
Planta. 2024 Oct 14;260(5):116. doi: 10.1007/s00425-024-04547-3.
Aluminium (Al) toxicity in acidic soils poses a significant challenge for crop cultivation and reduces crop productivity. The primary defense mechanism against Al toxicity involves the activation of organic acid secretion. In this study, responses of 9 Vigna mungo cultivars to Al toxicity were investigated, with a particular emphasis on the root system and crucial genes involved in Al tolerance using molecular cloning and expression analysis. Sensitive blackgram-KM2 cultivars exposed to 100-µM Al toxicity for 72 h exhibited a root-growth inhibition of approximately 66.17%. Significant loss of membrane integrity and structural deformative roots were found to be the primary symptoms of Al toxicity in blackgram. MATE (Multidrug and Toxic Compound Extrusion) and ALS3 (Aluminium Sensitive 3) genes were successfully cloned from a sensitive blackgram cv KM2 with phylogenetic analysis revealing their evolutionary relationship to Vigna radiata and Glycine max. The MATE gene is mainly localized in the plasma membrane, and highly expressed under Al, thus suggesting its role in transports of citrate-Al complexes, and detoxifying Al within plant cells. In addition, ALS3 was also induced under Al toxicity, which codes the UDP-glucose transporter and is required for the maintenance of ions homeostasis. In summary, this study highlights the understanding of Al toxicity and underlying molecular mechanisms linked to the efflux of organic acid in blackgram, ultimately aiding the framework for the development of strategies to enhance the resilience of blackgram and other pulse crops in Al-rich soils.
在酸性土壤中，铝（Al）毒性会对作物种植造成严重挑战，降低作物产量。作物抵御铝毒性的主要防御机制涉及有机酸分泌的激活。本研究采用分子克隆和表达分析方法，研究了 9 个豇豆品种对铝毒性的响应，特别关注根系统和与铝耐受相关的关键基因。在 72 小时内，敏感的黑豆品种 KM2 暴露在 100 μM 的铝毒性下，其根生长抑制率约为 66.17%。研究发现，膜完整性的显著损失和结构变形的根是黑豆铝毒性的主要症状。成功地从敏感的黑豆品种 KM2 中克隆出 MATE（多药和毒性化合物外排）和 ALS3（铝敏感 3）基因，系统进化分析表明它们与豇豆和大豆具有进化关系。MATE 基因主要定位于质膜上，在铝胁迫下高度表达，因此推测其在柠檬酸-铝复合物的转运和植物细胞内的铝解毒中发挥作用。此外，ALS3 也在铝毒性下被诱导，它编码 UDP-葡萄糖转运蛋白，是维持离子稳态所必需的。综上所述，本研究强调了对黑豆中有机酸外排与铝毒性相关的分子机制的理解，最终为在富含铝的土壤中提高黑豆和其他豆科作物的抗逆性制定策略提供了框架。
