《植物生理学报》 2018, 54(11): 1687-1694

根非蛋白巯基化合物在箭舌豌豆两个品种镉耐性中的作用及机理

芮海云^1,2, 张兴兴², 庄凯², 沈振国², 张芬琴^3,*

¹泰州学院医药与化学化工学院, 江苏泰州225300; ²南京农业大学生命科学学院, 南京210095; ³河西学院农业与生物技术学院, 甘肃张掖734000

通信作者：张芬琴；E-mail: fenqinzh@163.com

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

收稿：2018-10-08   修定：2018-11-20

资助：国家自然科学基金(31160053)、江苏省高校自然科学基金(17KJB10014)和泰州学院博士基金(TZXY2015JBJJ005)。

The role of root non-protein thiols in cadmium tolerance of two Vicia sativa varieties and the underlying mechanism

RUI Hai-Yun^1,2, ZHANG Xing-Xing², ZHUANG Kai², SHEN Zhen-Guo², ZHANG Fen-Qin^3,*

¹College of Pharmacy and Chemistry & Chemical Engineering, Taizhou University, Taizhou, Jiangsu 225300, China; ² College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China; ³ College of Agriculture and Biotechnology, Hexi University, Zhangye, Gansu 734000, China

Corresponding author: ZHANG Fen-Qin; E-mail: fenqinzh@163.com

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