Cell Wall Pectin and its Methyl-esterification in Transition Zone Determine Al Resistance in Cultivars of Pea (Pisum sativum).
Cell Wall Pectin and its Methyl-esterification in Transition Zone Determine Al Resistance in Cultivars of Pea (Pisum sativum).
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DOI：
10.3389/fpls.2016.00039
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发表时间：
2016
影响因子：
5.6
通讯作者：
Yu M
中科院分区：
文献类型：
--
作者：
Li X;Li Y;Qu M;Xiao H;Feng Y;Liu J;Wu L;Yu M
植物对铝胁迫的最初反应是根伸长受到抑制，而过渡区是根尖对铝最敏感的区域，它可能感知到铝的存在并调节根系对铝毒的反应。研究了铝处理（30 μ M，24 h）对豌豆（PisumsativumL.）以抗铝豌豆品种Onward和铝敏感豌豆品种Sima为材料，研究了豌豆根系过渡区对铝毒的反应是否决定了豌豆品种的铝抗性。结果表明，西玛的根相对伸长（RRE）较低，铝含量较高，这与铝诱导两品种根段果胶含量增加有关。铝敏感品种果胶含量的增加比抗铝品种显著。铝毒还诱导了根系过渡区果胶甲酯酶（PME）的增加，铝敏感品种Sima的PME是抗铝品种Onward的2.2倍，从而导致铝敏感品种Sima根系过渡区脱甲酯化果胶含量增加。铝敏感品种西玛根系过渡区的去甲酯化果胶含量越高，铝在细胞壁和细胞质中的积累量越大。我们的研究结果提供的证据表明，果胶含量和PME活性的增加铝毒性合作，以确定铝敏感性的根过渡区，赋予铝抗性豌豆品种（豌豆）。
The initial response of plants to aluminum (Al) is the inhibition of root elongation, while the transition zone is the most Al sensitive zone in the root apex, which may sense the presence of Al and regulate the responses of root to Al toxicity. In the present study, the effect of Al treatment (30 μM, 24 h) on root growth, Al accumulation, and properties of cell wall of two pea (Pisum sativum L.) cultivars, cv Onward (Al-resistant) and cv Sima (Al-sensitive), were studied to disclose whether the response of root transition zone to Al toxicity determines Al resistance in pea cultivars. The lower relative root elongation (RRE) and higher Al content were founded in cv Sima compared with cv Onward, which were related to Al-induced the increase of pectin in root segments of both cultivars. The increase of pectin is more prominent in Al-sensitive cultivar than in Al-resistant cultivar. Aluminum toxicity also induced the increase of pectin methylesterases (PME), which is 2.2 times in root transition zone in Al-sensitive cv Sima to that of Al resistant cv Onward, thus led to higher demethylesterified pectin content in root transition zone of Al-sensitive cv Sima. The higher demethylesterified pectin content in root transition zone resulted in more Al accumulation in the cell wall and cytosol in Al-sensitive cv Sima. Our results provide evidence that the increase of pectin content and PME activity under Al toxicity cooperates to determine Al sensitivity in root transition zone that confers Al resistance in cultivars of pea (Pisum sativum).