PDF(Pubmed)
Abstract：
In acidic soils, aluminum (Al) toxicity inhibits the growth and development of plant roots and affects nutrient and water absorption, leading to reduced yield and quality. Therefore, it is crucial to investigate and identify candidate genes for Al tolerance and elucidate their physiological and molecular mechanisms under Al stress. In this study, we identified a new gene OsAlR3 regulating Al tolerance, and analyzed its mechanism from physiological, transcriptional and metabolic levels. Compared with the WT, malondialdehyde (MDA) and hydrogen peroxide (H2O2) content were significantly increased, superoxide dismutase (SOD) activity and citric acid (CA) content were significantly decreased in the osalr3 mutant lines when exposed to Al stress. Under Al stress, the osalr3 exhibited decreased expression of antioxidant-related genes and lower organic acid content compared with WT. Integrated transcriptome and metabolome analysis showed the phenylpropanoid biosynthetic pathway plays an important role in OsAlR3-mediated Al tolerance. Exogenous CA and oxalic acid (OA) could increase total root length and enhance the antioxidant capacity in the mutant lines under Al stress. Conclusively, we found a new gene OsAlR3 that positively regulates Al tolerance by promoting the chelation of Al ions through the secretion of organic acids, and increasing the expression of antioxidant genes.
摘要：
在酸性土壤中，铝（Al）毒性抑制植物根系的生长和发育，影响养分和水分的吸收，导致产量和质量下降。因此,研究和鉴定铝耐受的候选基因，阐明其在铝胁迫下的生理和分子机制至关重要。在这项研究中,我们发现了一个调节耐铝的新基因OsAlR3，并从生理上分析了其机制，转录和代谢水平。与WT相比,丙二醛(MDA)和过氧化氢(H2O2)含量显著升高,当暴露于Al胁迫时，osalr3突变系的超氧化物歧化酶（SOD）活性和柠檬酸（CA）含量显着降低。在Al应力下,与WT相比，osalr3表现出抗氧化相关基因的表达减少，有机酸含量降低。综合转录组和代谢组分析显示，苯丙素生物合成途径在OsAlR3介导的Al耐受中起重要作用。外源CA和草酸（OA）可以增加Al胁迫下突变体的总根长度并增强其抗氧化能力。最后，我们发现了一个新的基因OsAlR3，它通过分泌有机酸来促进铝离子的螯合，从而正向调节铝的耐受性，增加抗氧化基因的表达。
