《植物生理学报》 2018, 54(11): 1687-1694
摘 要：研究了镉胁迫下箭舌豌豆两个品种(镉耐性品种‘L3’和镉敏感品种‘ZM’)根中非蛋白巯基化合物(NPTs)含量的变化及在箭舌豌豆镉耐性中的作用和机理。结果表明: 箭舌豌豆两个品种根中镉主要分布于可溶性组分, NPTs是主要的镉结合物。镉胁迫下敏感品种‘ZM’根中NPTs含量大于耐性品种‘L3’, NPTs结合镉的量也大于‘L3’, 但两个品种根中NPTs结合镉占总可溶性镉的比值无显著差异。镉胁迫下箭舌豌豆两个品种根中, γ-谷氨酰半胱氨酸合成酶(γ-ECS)基因的转录上调, 谷胱甘肽(GSH)和植物螯合肽(PCs)含量升高, ‘ZM’较‘L3’更显著。γ-ECS的强抑制剂BSO (L-buthionine-sulfoximine)和镉共处理降低了箭舌豌豆两个品种的镉耐性, 箭舌豌豆两个品种根中PCs已不能检出, H2O2含量升高, 说明NPTs通过螯合作用和抗氧化作用, 增强了箭舌豌豆的镉耐性, 但NPTs响应不是导致箭舌豌豆两个品种镉耐性差异的原因。
关键词：非蛋白巯基化合物; 箭舌豌豆; 镉耐性
Corresponding author: ZHANG Fen-Qin; E-mail: firstname.lastname@example.org
Abstract:Our study was carried out to investigate the changes of non-protein thiols (NPTs) content in the roots of two V. sativa varieties (Cd-tolerant variety ‘L3’ and Cd-sensitive variety ‘ZM’) under cadmium stress and the effect and mechanism of NPTs in V. sativa cadmium tolerance. Our results showed that majority of cadmium was located in soluble fraction, and most of the soluble cadmium bound to NPTs in two V. sativa varieties. NPTs was more significantly induced and bound to more cadmium in ‘ZM’ than in ‘L3’, but there were no significant differences between two varieties in the proportion of Cd bound to NPTs. Cd treatments increased the level of γ-glutamylcysteine synthetase (γ-ECS) gene transcription and GSH and PCs contents more significantly in ‘ZM’ than in ‘L3’. When treated with Cd and BSO, a potent inhibitor of γ-ECS, PCs content and Cd tolerance of two varieties decreased, and H2O2 content increased synchronistically. These ﬁndings suggested that NPTs contributed to Cd tolerance of two V. sativa varieties by chelation and antioxidation, but they might not contribute to the difference of Cd tolerance between ‘L3’ and ‘ZM’.
Key words: non-protein thiols; Vicia sativa L.; Cd tolerance
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