Induction of vacuolar ATPase and mitochondrial ATP synthase by aluminum in an aluminum-resistant cultivar of wheat
Induction of vacuolar ATPase and mitochondrial ATP synthase by aluminum in an aluminum-resistant cultivar of wheat
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DOI：
10.1104/pp.125.4.2068
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发表时间：
2001-04-01
期刊：
影响因子：
7.4
通讯作者：
Taylor, GJ
中科院分区：
文献类型：
--
作者：
Hamilton, CA;Good, AG;Taylor, GJ
最近在小麦（Triticum aestivum）cv PT 741的抗铝栽培品种中发现了两种51-kD铝（Al）诱导的蛋白质（RMP 51，51 kD的根膜蛋白）（Basu et al.，1994年a）。这些蛋白质在由Al抗性cv PT 741和Al敏感性cv Katepwa之间的杂交产生的分离群体中与铝抗性表型分离（Taylor等人，1997年）。通过连续洗脱电泳纯化蛋白质，并通过肽微测序进行分析。序列分析表明，它们与液泡H+-ATP酶（V-ATP酶）的B亚基和线粒体ATP合成酶（F1 F0-ATP酶）的α-和β-亚基同源。为了证实这些ATP酶是由铝诱导的，在铝胁迫下分析ATP酶活性和转录水平。Al对V-ATPase和F_1F_0-ATPase活性均有诱导作用，且对0 ~ 150 μ M Al的诱导作用呈剂量依赖性北方分析表明，编码V-ATPase的B亚基的转录本以剂量依赖性方式增加了2.2倍，而编码F1 F0-ATP酶α亚基的转录物水平保持恒定。此外，还研究了铝对其它品种ATP酶活性的影响。抗铝品种，品种PT 741，是唯一的品种，显示V-和F1 F0-ATP酶的诱导。这些结果表明，V-ATPase在品种PT 741是专门响应铝胁迫与ATP合成酶提供的ATP，以维持细胞内的能量平衡，其活性所需的。
Two 51-kD aluminum (Al)-induced proteins (RMP51, root membrane proteins of 51 kD) were recently discovered in an aluminum-resistant cultivar of wheat (Triticum aestivum) cv PT741 (Basu et al., 1994a). These proteins segregate with the aluminum resistance phenotype in a segregating population arising from a cross between Al-resistant cv PT741 and Al-sensitive cv Katepwa (Taylor et al., 1997). The proteins have been purified by continuous elution electrophoresis and analyzed by peptide microsequencing. Sequence analysis of the purified peptides revealed that they are homologous to the B subunit of the vacuolar H+-ATPase (V-ATPase) and the alpha- and beta -subunits of the mitochondrial ATP synthase (F1F0-ATPase). To confirm that these ATPases are induced by Al, ATPase activity and transcript levels were analyzed under Al stress. Both V-ATPase and F1F0-ATPase activities were induced by Al and responded in a dose-dependent manner to 0 to 150 muM Al. In contrast, plasma membrane H+-ATPase (P-ATPase) activity decreased to 0.5x control levels, even when plants were exposed to 25 muM Al. Northern analysis showed that the transcript encoding the B subunit of V-ATPase increased by 2.2x in a dose-dependent manner, whereas levels of the transcript encoding the alpha -subunit of F1F0-ATPase remained constant. The effect of Al on ATPase activity in other cultivars was also examined. The Al-resistant cultivar, cv PT741, was the only cultivar to show induction of V- and F1F0-ATPases. These results suggest that the V-ATPase in cv PT741 is responding specifically to Al stress with the ATP required for its activity supplied by ATP synthase to maintain energy balance within the cell.