《植物生理学报》 2015, 51(10): 1669-1677

水杨酸浸种对镉诱导两种豆科植物根活性氧产生的缓解及其机理

张喜峰¹, 张红晓², 关天霞¹, 曾秀存¹, 张芬琴^1,*

¹河西学院农业与生物技术学院, 甘肃张掖734000; ²河南科技大学农学院, 河南洛阳471003

通信作者：张芬琴；E-mail: fenqinzh@hxu.edu.cn；Tel: 0936-8280648

摘　要：

研究了水杨酸(SA)浸种对镉(Cd)耐性不同的两种豆科植物——绿豆和箭舌豌豆种子萌发及其幼苗生长的影响，以及Cd胁迫下SA浸种对两种豆科植物幼苗根内活性氧产生的缓解效应及其机理。结果表明: (1)与各自的对照相比, 100μmol•L^-1 SA浸种对两种豆科植物种子发芽率无明显影响, 但使绿豆和箭舌豌豆幼苗根长分别增加了54.63%和32.94%; 当SA浓度达1 000 μmol•L^-1时, 绿豆和箭舌豌豆种子的发芽率分别下降了5.33%和3.33%, 根长分别下降了16.64%和27.76%; (2)50 μmol•L^-1 Cd处理明显增强了两种豆科植物根内过氧化氢(H₂O₂)和超氧阴离子(O₂ ¯• )的产生, 抑制了根的伸长; 而Cd处理前的100 μmol•L^-1 SA浸种使H₂O₂和O₂ ¯• 产生显著降低, Cd抑制根伸长生长的作用明显减轻。同时, SA浸种也明显增强了Cd胁迫下两种豆科植物根内超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性、降低了过氧化氢酶(CAT)的活性。结果说明: SA可缓解Cd诱导的活性氧产生, 这种缓解效应可能与其上调SOD和APX活性有关。

关键词：水杨酸; 浸种; 缓解; 活性氧; 豆科植物

收稿：2015-08-04   修定：2015-09-28

资助：国家自然科学基金(31160053)。

Alleviating Effect and Mechanism of Seed Soaking with Salicylic Acid on Reactive Oxygen Species Production Induced by Cadmium in the Roots of Two Legume Species

ZHANG Xi-Feng¹, ZHANG Hong-Xiao², GUAN Tian-Xia¹, ZENG Xiu-Cun¹, ZHANG Fen-Qin^1,*

¹College of Agriculture and Biotechnology, Hexi University, Zhangye, Gansu 734000, China; ²College of Agriculture, Henan University of Science and Technology, Luoyang, Henan 471003, China

Corresponding author: ZHANG Fen-Qin; E-mail: fenqinzh@hxu.edu.cn; Tel: 0936-8280648

Abstract:

Our study was carried out to explore the effect of seed soaking with salicylic acid (SA) on the seed germination and seedling growth of two legume species with different cadmium (Cd) tolerance, viz. mung bean and common vetch. The alleviating effect of seed soaking with SA on the reactive oxygen species production induced by Cd in the roots of two legume species, and its mechanism was also investigated. Our results show that: (1) compared with its control, the seed germination of two legume species was not significantly affected by soaking with 100 μmol•L^-1 SA, but the root length of mung bean was significantly affected, increasing by 54.63% and of common vetch by 32.94%. The seed germination of mung bean and common vetch soaked with 1 000 μmol•L^-1 SA decreased by 5.33% and 3.33%, respectively, and the root length of mung bean and common vetch decreased by 16.64% and 27.76%, respectively. (2) The production of hydrogen peroxide (H₂O₂) and superoxide anion (O₂ ¯• ) in roots of mung bean and vetch were significantly increased by the 50 μmol•L^-1 Cd treatment, but roots elongation was inhibited. By seeds soaking with 100 μmol•L^-1 SA before Cd induction, the production of H₂O₂ and O₂ ¯• decreased. In addition, after soaking with SA, the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) were increased but the activity of catalase (CAT) decreased, in roots of both species. These results indicate that SA could alleviate the reactive oxygen species production induced by Cd, and this alleviation is likely associated with up-regulation of SOD and APX activities by SA.

Key words: salicylic acid; seed soaking; alleviation; reactive oxygen species; legume species