Molecular mapping of a gene responsible for Al-activated secretion of citrate in barley
Molecular mapping of a gene responsible for Al-activated secretion of citrate in barley
复制标题
DOI：
10.1093/jxb/erh152
复制
发表时间：
2004-06-01
影响因子：
6.9
通讯作者：
Takeda, K
中科院分区：
文献类型：
--
作者：
Ma, JF;Nagao, S;Takeda, K
铝（X）毒害是大麦（Hordeum vulgare L.）酸性土壤上。大麦抗铝品种通过从根部分泌柠檬酸盐来从外部解毒铝。为了将大麦抗铝性的遗传和生理联系起来，对控制大麦抗铝性和铝激活柠檬酸分泌的基因进行了定位。铝诱导的根生长抑制的100个F-2幼苗来自抗铝品种（Murasakimochi）和铝敏感品种（Morex）的分析表明，与铝抗性相关的基因定位于染色体4 H，紧密连锁的微卫星标记Bmag 353。对来自4 H染色体上铝抗性杂合的F3代植株的59株F4代幼苗进行QTL分析，结果表明，一个与铝激活的柠檬酸分泌相关的基因也与微卫星标记Bmag 353紧密连锁。该QTL解释了该群体中柠檬酸盐分泌的50%以上的表型变异。这些结果表明，大麦4 H染色体上控制Al抗性的基因与Al激活的柠檬酸分泌基因是一致的，柠檬酸分泌是大麦抗X的机制之一。同时与铝抗性和柠檬酸分泌相关的微卫星标记的鉴定为分子标记辅助选择抗铝品系提供了一个有价值的工具。
Aluminium (X) toxicity is an important limitation to barley (Hordeum vulgare L.) on acid soil. Al-resistant cultivars of barley detoxify Al externally by secreting citrate from the roots. To link the genetics and physiology of Al resistance in barley, genes controlling Al resistance and Al-activated secretion of citrate were mapped. An analysis of Al-induced root growth inhibition from 100 F-2 seedlings derived from an Al-resistant cultivar (Murasakimochi) and an Al-sensitive cultivar (Morex) showed that a gene associated with Al resistance is localized on chromosome 4H, tightly linked to microsatellite marker Bmag353. Quantitative trait locus (QTL) analysis from 59 F-4 seedlings derived from an F-3 plant heterozygous at the region of Al resistance on chromosome 4H showed that a gene responsible for the Al-activated secretion of citrate was also tightly linked to microsatellite marker Bmag353. This QTL explained more than 50% of the phenotypic variation in citrate secretion in this population. These results indicate that the gene controlling Al resistance on barley chromosome 4H is identical to that for Al-activated secretion of citrate and that the secretion of citrate is one of the mechanisms of X resistance in barley. The identification of the microsatellite marker associated with both Al resistance and citrate secretion provides a valuable tool for marker-assisted selection of Al-resistant lines.