Moons Ann
National Research Council Canada, Biotechnology Research Institute Montreal Canada, H4P 2R2.
Vitam Horm. 2005;72:155-202. doi: 10.1016/S0083-6729(05)72005-7.
Plant glutathioneS-transferases (GSTs) are a heterogeneous superfamily of multifunctional proteins, grouped into six classes. The tau (GSTU) and phi (GSTF) class GSTs are the most represented ones and are plant-specific, whereas the smaller theta (GSTT) and zeta (GSTZ) classes are also found in animals. The lambda GSTs (GSTL) and the dehydroascorbate reductases (DHARs) are more distantly related. Plant GSTs perform a variety of pivotal catalytic and non-enzymatic functions in normal plant development and plant stress responses, roles that are only emerging. Catalytic functions include glutathione (GSH)-conjugation in the metabolic detoxification of herbicides and natural products. GSTs can also catalyze GSH-dependent peroxidase reactions that scavenge toxic organic hydroperoxides and protect from oxidative damage. GSTs can furthermore catalyze GSH-dependent isomerizations in endogenous metabolism, exhibit GSH-dependent thioltransferase safeguarding protein function from oxidative damage and DHAR activity functioning in redox homeostasis. Plant GSTs can also function as ligandins or binding proteins for phytohormones (i.e., auxins and cytokinins) or anthocyanins, thereby facilitating their distribution and transport. Finally, GSTs are also indirectly involved in the regulation of apoptosis and possibly also in stress signaling. Plant GST genes exhibit a diversity of expression patterns during biotic and abiotic stresses. Stress-induced plant growth regulators (i.e., jasmonic acid [JA], salicylic acid [SA], ethylene [ETH], and nitric oxide [NO] differentially activate GST gene expression. It is becoming increasingly evident that unique combinations of multiple, often interactive signaling pathways from various phytohormones and reactive oxygen species or antioxidants render the distinct transcriptional activation patterns of individual GSTs during stress. Underestimated post-transcriptional regulations of individual GSTs are becoming increasingly evident and roles for phytohormones (i.e., ABA and JA) in these processes are being anticipated as well. Finally, indications are emerging that NO may regulate the activity of specific plant GSTs. In this review, the current knowledge on the regulatory and functional interactions of phytohormones and plant GSTs are covered. We refer to a previous extensive review on plant GSTs (Marrs, 1996) for most earlier work. An introduction on the classification and roles of plant GSTs is included here, but these topics are more extensively discussed in other reviews (Dixon et al., 2002a; Edwards et al., 2000; Frova, 2003).
植物谷胱甘肽S-转移酶（GSTs）是一个多功能蛋白质的异质超家族，分为六个类别。其中，tau（GSTU）和phi（GSTF）类GSTs最为常见且具有植物特异性，而较小的theta（GSTT）和zeta（GSTZ）类在动物中也有发现。lambda GSTs（GSTL）与脱氢抗坏血酸还原酶（DHARs）的关系更为疏远。植物GSTs在正常植物发育和植物应激反应中发挥着多种关键的催化和非酶功能，这些作用才刚刚被发现。催化功能包括在除草剂和天然产物的代谢解毒过程中进行谷胱甘肽（GSH）结合。GSTs还可以催化依赖GSH的过氧化物酶反应，清除有毒的有机氢过氧化物并防止氧化损伤。此外，GSTs可以在内源代谢中催化依赖GSH的异构化反应，表现出依赖GSH的硫转移酶活性以保护蛋白质功能免受氧化损伤，以及在氧化还原稳态中发挥DHAR活性。植物GSTs还可以作为植物激素（即生长素和细胞分裂素）或花青素的配体蛋白或结合蛋白，从而促进它们的分布和运输。最后，GSTs也间接参与细胞凋亡的调控，可能还参与应激信号传导。植物GST基因在生物和非生物胁迫期间表现出多种表达模式。胁迫诱导的植物生长调节剂（即茉莉酸[JA]、水杨酸[SA]、乙烯[ETH]和一氧化氮[NO]）会差异激活GST基因表达。越来越明显的是，来自各种植物激素以及活性氧或抗氧化剂的多个（通常是相互作用的）信号通路的独特组合，导致了胁迫期间各个GSTs不同的转录激活模式。单个GSTs被低估的转录后调控越来越明显，植物激素（即脱落酸和JA）在这些过程中的作用也备受期待。最后，有迹象表明NO可能调节特定植物GSTs的活性。在这篇综述中，涵盖了关于植物激素与植物GSTs的调控和功能相互作用的当前知识。对于大多数早期工作，我们参考了之前一篇关于植物GSTs的广泛综述（Marrs，1996）。这里包含了关于植物GSTs的分类和作用的介绍，但这些主题在其他综述中有更广泛的讨论（Dixon等人，2002a；Edwards等人，2000；Frova，2003）。
