《植物生理学报》 2013, 49(6): 561-567

盐胁迫下硫化氢调控杨树根系的离子流

朱会朋, 孙健, 赵楠, 马旭君, 张玉红, 沈昕, 陈少良^*

北京林业大学生物科学与技术学院, 北京100083

通信作者：陈少良；E-mail: lschen@bjfu.edu.cn；Tel: 010-62338129

摘　要：

本文应用非损伤微测技术(non-invasive micro-test technique, NMT)研究了H2S对盐胁迫下耐盐的胡杨和不耐盐的群众杨根部K+、Na+和H+流速的影响。结果表明, 两种杨树根系在瞬时(100 mmol·L-1 NaCl)和短期(24 h, 50 mmol·L-1 NaCl)盐胁迫下呈现出K+外流, 这种盐诱导的根部K+外流能被50 μmol·L-1 NaHS抑制。此外, H2S能增加短期盐胁迫下Na+的外排, 而Na+的外流被Na+/H+逆向转运体抑制剂amiloride或者质膜H+泵抑制剂sodium orthovanadate有效抑制。盐胁迫下, H2S对不耐盐的群众杨根系K+外流的抑制作用和对Na+/H+逆向转运的促进作用高于耐盐的胡杨。据此推测, H2S是通过上调杨树根系 胞质膜Na+/H+逆向转运体系(H+泵和Na+/H+逆向转运体), 促进Na+和H+逆向跨膜转运, 并且, H+泵通过抑制去极化激活的离子通道来限制盐诱导的K+外流。

关键词：胡杨; 群众杨; K+/Na+平衡; NaHS; 非损伤微测技术

收稿：2013-01-28   修定：2013-04-27

资助：国家自然科学基金(31270654和31170570)、北京市自然科学基金(6112017)、高等学校学科创新引智计划(111项目, B13007)、中央高校基本科研业务费专项资金(JC2011-2)和北京市优秀博士学位论文指导教师专项基金(YB20081002201)。

Hydrogen Sulfide Mediates Ion Fluxes in Root of Poplars under NaCl Stress

ZHU Hui-Peng, SUN Jian, ZHAO Nan, MA Xu-Jun, ZHANG Yu-Hong, SHEN Xin, CHEN Shao-Liang*

College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China

Corresponding author: CHEN Shao-Liang; E-mail: lschen@bjfu.edu.cn; Tel: 010-62338129

Abstract:

Using the non-invasive micro-test technique (NMT), the effects of exogenous NaHS (a H2S donor) on ion fluxes in roots were investigated in a salt-tolerant species Populus euphratica and a salt-sensitive poplar spcies Populus popularis under the instantaneous salt stress (100 mmol·L-1 NaCl) and short-term salt stress (24 h, 50 mmol·L-1 NaCl). Both NaCl stress caused a K+ flux in roots of the poplar, and the salt-induced K+ flux was markedly inhibited by 50 µmol·L-1 NaHS. Moreover, the Na+ flux increment could be induced by NaHS under short-term salt stress, and also could be effectively inhibited by amiloride (a Na+/H+ antiporter inhibitor) or so-dium orthovanadate (a plasma membrane H+-ATPase inhibitor). The results showed that the effects of H2S on the inbition of K+ flux and the enhancement of Na+/H+ antiport were more remarkably in the salt-sensitive P. po-pularis, compared to the salt-resistant P. euphratica. These concluded that the beneficial effects of H2S were presumably due to the upward regulation of Na+/H+ antiport system (H+ pump and Na+/H+ antiporter), which drived the Na+/H+ exchange across the PM, and simultaneously restricted the K+ flux through depolarization-ac-tivated channels.

Key words: Populus euphratica; Populus popularis; K+/Na+ homeostasis; NaHS; non-invasive micro-test technigue