Molecular and physiological strategies to increase aluminum resistance in plants
Molecular and physiological strategies to increase aluminum resistance in plants
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DOI：
10.1007/s11033-011-0954-4
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发表时间：
2012-03-01
影响因子：
2.8
通讯作者：
Reyes-Diaz, Marjorie
中科院分区：
文献类型：
--
作者：
Inostroza-Blancheteau, Claudio;Rengel, Zed;Reyes-Diaz, Marjorie
铝毒是酸性土壤上植物生长的主要限制因素。根分生组织是铝毒积累的第一个部位，因此根伸长受到抑制是铝毒最明显的生理表现。植物可以通过避免（铝排斥）和/或耐受机制（细胞内的铝解毒）来抵抗铝毒性。铝排斥涉及从根尖分泌的有机酸阴离子，而耐受机制包括内部铝解毒的有机酸阴离子和增强清除自由基的氧自由基。在理解与铝排斥机制相关的分子事件中最重要的进展之一是鉴定了小麦根细胞中的ALMT 1基因（铝激活的苹果酸转运蛋白），该基因编码质膜阴离子通道，允许有机酸阴离子（如苹果酸、柠檬酸或草酸）流出。另一方面，自由基的清除依赖于参与抗氧化防御的基因的表达，例如过氧化物酶（例如在拟南芥和烟草中）、过氧化氢酶（例如在辣椒中）和来自T.小麦然而，其他最近的研究结果表明，活性氧（ROS）诱导的应力可能是由于酸性（低pH值）条件，而不是铝应力。本文综述了近年来有关植物铝毒及其抗性的分子和生理机制的研究进展。在理解植物用于科普铝毒性的一些基本策略方面取得了进展。此外，我们还讨论了铝毒性的生理和分子反应，包括在几种植物中已被确定和鉴定的抗铝基因。更好地了解这些策略和机制是必不可少的，以提高植物的性能在酸性，铝毒土壤。
Aluminum (Al) toxicity is a primary limitation to plant growth on acid soils. Root meristems are the first site for toxic Al accumulation, and therefore inhibition of root elongation is the most evident physiological manifestation of Al toxicity. Plants may resist Al toxicity by avoidance (Al exclusion) and/or tolerance mechanisms (detoxification of Al inside the cells). The Al exclusion involves the exudation of organic acid anions from the root apices, whereas tolerance mechanisms comprise internal Al detoxification by organic acid anions and enhanced scavenging of free oxygen radicals. One of the most important advances in understanding the molecular events associated with the Al exclusion mechanism was the identification of the ALMT1 gene (Al-activated malate transporter) in Triticum aestivum root cells, which codes for a plasma membrane anion channel that allows efflux of organic acid anions, such as malate, citrate or oxalate. On the other hand, the scavenging of free radicals is dependent on the expression of genes involved in antioxidant defenses, such as peroxidases (e.g. in Arabidopsis thaliana and Nicotiana tabacum), catalases (e.g. in Capsicum annuum), and the gene WMnSOD1 from T. aestivum. However, other recent findings show that reactive oxygen species (ROS) induced stress may be due to acidic (low pH) conditions rather than to Al stress. In this review, we summarize recent findings regarding molecular and physiological mechanisms of Al toxicity and resistance in higher plants. Advances have been made in understanding some of the underlying strategies that plants use to cope with Al toxicity. Furthermore, we discuss the physiological and molecular responses to Al toxicity, including genes involved in Al resistance that have been identified and characterized in several plant species. The better understanding of these strategies and mechanisms is essential for improving plant performance in acidic, Al-toxic soils.