Aluminium-induced alteration of ion homeostasis in root tip vacuoles of two maize varieties differing in Al tolerance
Aluminium-induced alteration of ion homeostasis in root tip vacuoles of two maize varieties differing in Al tolerance
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DOI：
10.1016/j.plantsci.2011.01.022
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发表时间：
2011-03-01
期刊：
影响因子：
5.2
通讯作者：
Poschenrieder, Charlotte
中科院分区：
文献类型：
--
作者：
Garzon, Teresa;Gunse, Benet;Poschenrieder, Charlotte
根伸长是植物铝毒作用的主要靶点。本研究的目的是看看铝诱导的离子稳态的干扰是否与根伸长的抑制有关。为此，对两个抗铝性不同的玉米品种根尖的生长速率、细胞质游离钙（Ca ~（2+））、液泡中磷酸盐（Pi）、钾（K ~+）、硝酸盐（NO ~（3-））和苹果酸含量、苹果酸和柠檬酸分泌量以及硝酸还原酶活性进行了分析。铝处理影响根系生长和细胞质Ca ~（2+）在铝敏感品种Bakero，但不耐铝品种Sikuani。然而，这两个品种遭受铝诱导的液泡K+和磷酸盐浓度下降。铝在Bakero比在Sikuani的影响更大的苹果酸浓度。铝暴露后，在两个品种的硝酸盐浓度增加。只有在Sikuani根际，pH值略有增加铝暴露。我们的数据是一致的假设，钙稳态的干扰是铝中毒综合征的早期事件。然而，铝诱导的根尖动态平衡的主要离子的改变似乎无关铝诱导的根伸长的抑制。(C)2011爱思唯尔爱尔兰有限公司保留所有权利。
Root elongation is a primary target of Al toxicity in plants. The objective of this study was to see whether Al-induced disturbance of ion homeostasis is related to the inhibition of root elongation. For this purpose, root growth rate, free cytoplasmic calcium (Ca2+) and vacuolar content of phosphate (P-i), potassium (K+), nitrate (NO3-) and malate, as well as malate and citrate exudation and nitrate reductase activity were analysed in tips of two Zea mays L varieties differing in Al resistance. Aluminium treatment affected root growth and cytoplasmic Ca2+ in the Al sensitive variety Bakero, but not in the Al tolerant variety Sikuani. However, both varieties suffered Al-induced decrease of vacuolar K+ and phosphate concentrations. Vacuolar malate concentrations were more affected by Al in Bakero than in Sikuani. Vacuolar nitrate concentrations increased upon Al exposure in both varieties. Only in Sikuani rhizosphere, pH slightly increased upon Al exposure. Our data are consistent with the hypothesis that disturbance of Ca2+ homeostasis is an early event in the Al toxicity syndrome. However, Al-induced alterations of the root tip homeostasis of major ions seem unrelated to Al-induced inhibition of root elongation. (C) 2011 Elsevier Ireland Ltd. All rights reserved.