摘要 植物主要有两个耐铝机制，即质外体的机制和共质体机制。在质外体机制内，酚类化合物的释放，粘液的形成，由根际pH上升所引起的酸碱障碍，以及有机酸分泌。几种植物针对铝的侵害，根系分泌有机酸，其中有机酸分泌机制可以防止铝穿过细胞膜进入共质体，以膜载体为介导，形成无毒的金属配合物。在共质体机制内，铝可以在细胞内与一些有机酸如柠檬酸、草酸、苹果酸形成稳定的配合物。铝进入细胞质中，一旦与细胞内的有机物络合，其毒性就会降低甚至消失，或者将游离的三价铝离子或铝配合物螯合剂运输并储存在细胞液泡中，而不带毒性。基因（ALMT家族基因，MATE家族基因）编码的膜转运蛋白和转录辅助因子以及增强基因表达的顺式元件，都参与了植物耐铝机制的应用。基于苹果酸分泌的耐铝机制的遗传研究，在ALMT家族中有基因编码铝活化苹果酸转运蛋白，在耐铝小麦品种(ET8)根尖中分离得到了铝诱导表达的ALMTl基因并命名为TaALMT1。TaALMT1基因被认为是从植物中克隆获得的第一个抗铝基因，它编码苹果酸分泌到根尖所需的转运蛋白，属于MATE家族的耐铝基因编码的蛋白和属于ALMT家族的耐铝基因编码的蛋白一样，以相同的方式参与植物耐铝过程。因此研究这些基因是改善铝的耐受性作物分子育种工作的重点。本文以不同品质的大麦（Hordeum vulgare L。）为材料，分析了铝毒害最显著的症状、作物幼苗期根长、耐铝遗传机制以及适应酸性土壤品种分子水平上进行研究。

本实验采用苗期单营养液水培鉴定方法,以相对根伸长量(RRE)作为耐铝毒性状的表型值,分析了大麦不同品种耐铝毒的基因型差异，并利用RIL群体进行了QTL定位。研究表明，不同的大麦基因型之间在耐铝性上存在着很大的差异。在2H、3H和4H染色体上共检测到3个耐铝毒的QTL，解释耐铝毒的变异介于8。6%-26。5%之间，其中有2个为新的耐铝毒QTL。源-于,优W尔Y论L文.网wwW.youeRw.com 原文+QQ75201,8766

Abstract  Mechanisms of aluminum tolerance in plants are classified as those that prevent Al ions from entering the root apical cells or that detoxify internal Al。 In symplastic mechanisms , release of phenolic compounds , mucilage formation , “pH barrier” resulting from increased pH in the rhizosphere , and organic acid exudation 。 Roots of several plant species secrete organic acids in response to Al , which are mediated by membrane transporters , resulting in the formation of non-toxic complexes with the metal 。In apoplastic mechanisms , Al enters the cytoplasm and is detoxified once inside the cell by complexation with Al organic compounds。Several compounds can form stable complexes with Al inside the cell，including organic acids such as citrate , oxalate , malate , and proteins 。 Free Al3+ or Al complexes with chelating agents can be transported to cell vacuoles , where they are stored without causing toxicity 。 Genes which belong to the ALMT family and the MATE family encoding membrane transporters and transcriptional factors, as well as cis-elements that enhance gene expression, are involved in the application of plant aluminum tolerance mechanisms。 The genetic control of the Al tolerance mechanism based on malate exudation is due to the action of genes encoding aluminum-activated malate transporters in the ALMT family。The first Al tolerance gene to be cloned in plants was designated TaALMT1,which encodes a transporter protein involved in malate exudation from root apices and is responsible for Al tolerance in wheat。 The protein encoded by the aluminum-resistant gene belonging to the MATE family is involved in the plant-resistant aluminum process in the same way as the ALMT family-resistant protein。Thus, studying these genes is the focus of  molecular breeding efforts aimed at improving aluminum tolerance in crops 。 In this article, we study the most significant symptoms of aluminum toxicity, crop seedling root length, plant aluminum tolerance mechanism and adapt to acidic soil varieties。