Institute of Botany, Slovak Academy of Sciences, Dúbravská cesta 14, SK-84523 Bratislava, Slovak Republic.
Plant Physiol Biochem. 2009 Nov-Dec;47(11-12):1069-74. doi: 10.1016/j.plaphy.2009.08.003. Epub 2009 Aug 19.
In the present work we investigated the activity of glutathione S-transferase (GST) and glutathione peroxidase (GPX) in barley root tip and their relation to root growth inhibition induced by different abiotic stresses. Cadmium-induced root growth inhibition is strongly correlated with increased GST and GPX activity. Similarly, strong induction of GPX and GST activity was observed in Hg-treated root tips, where also the highest root growth inhibition was detected. Relationship between increased GST activity and root growth inhibition was also observed during other heavy metal treatments. On the other hand, only a slight increase of GPX activity was observed after application of Pb, Ni, and Zn, while Co did not affect GPX activity. Similarly to Hg and Cd, Cu treatment caused a strong increase in GPX activity. GPX activity in barley root tips was not affected by cold, heat or drought treatment and only a slight increase was observed after salt or H(2)O(2) treatment. Apart from salt treatment, only a weak increase in GST activity was observed during heat, drought and H(2)O(2) stresses, while during cold treatment its activity slightly decreased. Some detected differences in the spatial distribution of GST and GPX activity along the root tip suggests that at least two proteins are responsible for these activities. These proteins play a crucial role not only during stresses, but also in unstressed seedlings in the differentiation processes of root tip. The application of different inhibitors suggests that the main proportion of these activities detected in barley root tip are probably catalysed by GSTs possessing also GPX activity.
在本工作中，我们研究了谷胱甘肽 S-转移酶（GST）和谷胱甘肽过氧化物酶（GPX）在大麦根尖中的活性及其与不同非生物胁迫诱导的根生长抑制的关系。镉诱导的根生长抑制与 GST 和 GPX 活性的增加密切相关。同样，在汞处理的根尖中也观察到 GPX 和 GST 活性的强烈诱导，其中也检测到最高的根生长抑制。在其他重金属处理中也观察到 GST 活性增加与根生长抑制之间的关系。另一方面，在施加 Pb、Ni 和 Zn 后仅观察到 GPX 活性的轻微增加，而 Co 不影响 GPX 活性。与 Hg 和 Cd 类似，Cu 处理导致 GPX 活性的强烈增加。大麦根尖中的 GPX 活性不受冷、热或干旱处理的影响，仅在盐或 H2O2 处理后观察到轻微增加。除盐处理外，仅在热、干旱和 H2O2 胁迫期间观察到 GST 活性的微弱增加，而在冷处理期间其活性略有下降。GST 和 GPX 活性在根尖上的空间分布的一些检测到的差异表明，至少有两种蛋白质负责这些活性。这些蛋白质不仅在胁迫期间，而且在未受胁迫的幼苗的根尖分化过程中也起着至关重要的作用。不同抑制剂的应用表明，在大麦根尖中检测到的这些活性的主要部分可能由具有 GPX 活性的 GST 催化。
