Coordinated responses of phytochelatins and metallothioneins to heavy metals in garlic seedlings
Coordinated responses of phytochelatins and metallothioneins to heavy metals in garlic seedlings
复制标题
大蒜幼苗中植物螯合素和金属硫蛋白对重金属的协调反应
DOI：
10.1016/j.plantsci.2005.07.010
复制
发表时间：
2005-12-01
期刊：
影响因子：
5.2
通讯作者：
Ma, M
中科院分区：
文献类型：
--
作者：
Zhang, HY;Xu, WZ;Ma, M
为了研究植物螯合素(PC)和金属硫蛋白(MTS)在大蒜对重金属耐性中的作用，采用RACE方法从大蒜幼苗中克隆了植物螯合素合成酶和2型MT的基因，命名为AsPCS1和AsMT2a。半定量逆转录聚合酶链式反应和PCS含量分析表明，镉处理1h内，根中AsPCS1的转录水平显著升高，伴随着PCs的急剧增加。然而，在镉处理的初期，根中AsMT2a的RNA表达略有增加，直到处理10h才出现明显的增加。AsPCS1和AsMT2a的RNA表达在不同的胁迫条件下表现出不同的效应。镉、砷和热激处理使根中AsPCS1转录本和PCs含量显著增加。这些结果表明AsPCS1和AsMT2a在胁迫下表现出相互的协同作用。讨论了这些结果对AsPCS1和AsMT2a在重金属暴露期间的不同调控的影响。(C)2005爱思唯尔爱尔兰有限公司。保留所有权利。
To evaluate the roles of phytochelatins (PCs) and metallothioneins (MTs) in heavy metal tolerance in garlic (Allium sativum L.), the cDNAs encoding a phytochelatin synthase and a type 2 MT were cloned from the seedlings of garlic using RACE method and designated AsPCS1 and AsMT2a. Semi-quantitative reverse transcriptase-PCR and PCs contents showed transcript levels of AsPCS1 in roots exposed to cadmium increased significantly within 1 h concomitant with a sharp increase of PCs. However, the RNA expression of AsMT2a in roots was slightly increased within the preliminary phases of cadmium treatment and an obvious increase did not occurred until 10 h of Cd exposure. Different effects on RNA expression of AsPCS1 and AsMT2a appeared under varied stresses. Treatment with cadmium, arsenic and heat shock resulted in a strong increase of AsPCS1 transcripts and PCs contents in roots. Theses results showed that AsPCS1 and AsMT2a displayed mutual coordination under the stresses. The implications of these results with respect to differential regulation of AsPCS1 and AsMT2a during heavy metal exposure are discussed. (c) 2005 Elsevier Ireland Ltd. All rights reserved.