文献类型：期刊文献

英文题名：Exogenous glutathione enhances cadmium accumulation and alleviates its toxicity in Populus x canescens

作者：Ding, Shen[1] Ma, Chaofeng[1] Shi, Wenguang[2] Liu, Wenzhe[2] Lu, Yan[2] Liu, Qifeng[2] Luo, Zhi-Bin[2]

第一作者：Ding, Shen

通信作者：Luo, ZB[1]

机构：[1]Northwest A&F Univ, Coll Forestry, Yangling 712100, Shaanxi, Peoples R China;[2]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Tree Genet & Breeding, Beijing 100091, Peoples R China

年份：2017

卷号：37

期号：12

起止页码：1697-1712

外文期刊名：TREE PHYSIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000422839200010)】；

基金：This study was jointly supported by the National Natural Science Foundation of China (Grant Nos. 31470618 and 31670609) and the National Key Research and Development Program (Grant no. 2016YFD0600105).

语种：英文

外文关键词：cadmium; net Cd2+ influx; Populus; reactive oxygen species; reduced glutathione; transcriptional regulation

摘要：Glutathione (GSH) plays an important role in cadmium (Cd) tolerance in woody plants, but the underlying mechanisms remain largely unknown. To elucidate the physiological and transcriptional regulation mechanisms of GSH-mediated Cd tolerance in woody plants, we exposed Populus x canescens (Ait.) Smith saplings to either 0 or 75 mu M Cd together with one of three external GSH levels. Glutathione treatments include buthionine sulfoximine (BSO, an inhibitor of GSH biosynthesis), no external GSH and exogenous GSH. External GSH resulted in higher Cd2+ uptake rate in the roots, greater Cd amount in poplars, lower Cd-induced H2O2 levels in the roots, and higher contents of endogenous GSH in Cd-treated roots and leaves. Furthermore, external GSH led to upregulated transcript levels of several genes including zinc/iron regulated transporter related protein 6.2 (ZIP6.2) and natural resistance-associated macrophage protein 1.3 (NRAMP1.3), which probably take part in Cd uptake, glutathione synthetase 2 (GS2) implicated in Cd detoxification, metal tolerance protein 1 (MTP1) and ATP-binding cassette transporter C3 (ABCC3) involved in Cd vacuolar accumulation in the roots, gamma-glutamylcysteine synthetase (ECS) and phytochelatin synthetase family protein 1 (PCS1) involved in Cd detoxification, and oligopeptide transporter 7 (OPT7) probably implicated in Cd detoxification in the leaves of Cd-exposed P. x canescens. In contrast, BSO often displayed the opposite effects on Cd-triggered physiological and transcriptional regulation responses in poplars. These results suggest that exogenous GSH can enhance Cd accumulation and alleviate its toxicity in poplars. This is probably attributed to external-GSH-induced higher net Cd2+ influx in the roots, greater Cd accumulation in aerial parts, stronger scavenging of reactive oxygen species, and transcriptional overexpression of several genes involved in Cd uptake, detoxification and accumulation.