铝(Al),植物生长的非必需金属,发挥显著的植物毒性作用,特别是在根系生长方面。人为活动会通过将Al3释放到土壤溶液中而加剧Al的毒性作用,尤其是在pH值低于5.5且矿物质含量丰富的酸性土壤中。铝诱导的植物毒性的严重程度取决于铝浓度等因素,离子形式,植物物种,和成长阶段。铝毒性导致根和芽生长受到抑制,植物生物量减少,水分吸收中断导致营养失衡,和生理上的不利变化,生物化学,和分子过程。这些影响共同导致植物产量和质量下降,随着土壤肥力的下降。植物在胁迫条件下采用各种机制来对抗Al毒性,包括将Al隔离在空泡中,分泌有机酸(OAs)如柠檬酸盐,草酸盐,和苹果酸从根尖细胞形成铝复合物,激活抗氧化酶,和过表达Al胁迫调节基因。最近的进展集中在加强OAs的渗出,以防止Al进入工厂,开发耐铝品种。基因转运蛋白家族,如ATP结合盒(ABC),铝激活苹果酸盐运输车(ALMT),天然抗性相关巨噬细胞蛋白(Nramp),多种药物和有毒化合物挤出(MATE),和水通道蛋白,在调节铝的毒性中起着至关重要的作用。这篇全面的综述审查了在细胞和分子水平上了解Al对植物的细胞毒性影响的最新进展。讨论了植物和科学家开发的减轻铝诱导的植物毒性的多种策略。此外,这篇综述探讨了最近的基因组发展,确定负责OAs渗出的候选基因,并深入研究了基因组介导的育种计划,分离转基因和高级育种品系以培养耐铝植物。
Aluminum (Al), a non-essential metal for plant growth, exerts significant phytotoxic effects, particularly on root growth. Anthropogenic activities would intensify Al\'s toxic effects by releasing Al3+ into the soil solution, especially in acidic soils with a pH lower than 5.5 and rich mineral content. The severity of Al-induced phytotoxicity varies based on factors such as Al concentration, ionic form, plant species, and growth stages. Al toxicity leads to inhibited root and shoot growth, reduced plant biomass, disrupted water uptake causing nutritional imbalance, and adverse alterations in physiological, biochemical, and molecular processes. These effects collectively lead to diminished plant yield and quality, along with reduced soil fertility. Plants employ various mechanisms to counter Al toxicity under stress conditions, including sequestering Al in vacuoles, exuding organic acids (OAs) like citrate, oxalate, and malate from root tip cells to form Al-complexes, activating antioxidative enzymes, and overexpressing Al-stress regulatory genes. Recent advancements focus on enhancing the exudation of OAs to prevent Al from entering the plant, and developing Al-tolerant varieties. Gene transporter families, such as ATP-Binding Cassette (ABC), Aluminum-activated Malate Transporter (ALMT), Natural resistance-associated macrophage protein (Nramp), Multidrug and Toxic compounds Extrusion (MATE), and aquaporin, play a crucial role in regulating Al toxicity. This comprehensive
review examined recent progress in understanding the cytotoxic impact of Al on plants at the cellular and molecular levels. Diverse strategies developed by both plants and scientists to mitigate Al-induced phytotoxicity were discussed. Furthermore, the
review explored recent genomic developments, identifying candidate genes responsible for OAs exudation, and delved into genome-mediated breeding initiatives, isolating transgenic and advanced breeding lines to cultivate Al-tolerant plants.