《植物生理学报》 2018, 54(6): 1111-1118

过氧化氢对镉胁迫下水稻种子萌发的缓解效应

杨波¹, 何俊瑜^2,*, 任艳芳^2,*, 王艳玲¹, 田丹¹

¹贵州大学农学院, 贵阳550025; ²常州大学环境与安全工程学院, 江苏常州213164

通信作者：何俊瑜；E-mail: junyuhe0303@sina.com, gzdx2006@126.com

摘　要：

为了探讨外源H₂O₂对镉胁迫下水稻种子萌发受抑的缓解作用, 以水稻品种‘中优169’为材料, 通过培养皿滤纸发芽法, 研究不同浓度H₂O₂对200 μmol·L^-1镉胁迫下水稻种子萌发、幼苗生长及相关生理指标的影响。结果表明, 在200 μmol·L^-1镉胁迫下, 水稻种子的萌发和幼苗生长表现出明显的抑制现象, 发芽势、发芽指数、活力指数及幼苗的根长、芽长和可溶性蛋白含量均显著降低, MDA含量显著增加, POD活性上升, SOD、APX及CAT的活性显著受到抑制。较低浓度(≤10 μmol·L^-1) H₂O₂处理能不同程度地增加幼苗的根长、芽长、根鲜重和芽鲜重, 提高镉胁迫下水稻种子的发芽指数和活力指数, 增强SOD、POD和APX活性并降低MDA含量, 从而缓解镉的毒害效应。其中5 μmol·L^-1 H₂O₂浸种处理对镉胁迫下水稻种子萌发和幼苗生长的缓解作用最好。高H₂O₂浓度对镉胁迫的缓解作用逐渐减弱, 当H₂O₂浓度达到50 μmol·L^-1时, 会加重镉胁迫的毒性。表明适宜浓度的H₂O₂可以提高水稻幼苗抗氧化能力, 缓解镉胁迫伤害。

关键词：水稻; 镉; 过氧化氢; 种子萌发; 生理特性

收稿：2017-12-08   修定：2018-05-15

资助：国家自然科学基金(31460100、31660477、31360413和41261095)。

Alleviating effect of hydrogen peroxide on seed germination of rice under cadmium stresss

YANG Bo¹, HE Jun-Yu^2,*, REN Yan-Fang^2,*, WANG Yan-Ling¹, TIAN Dan¹

¹College of Agriculture, Guizhou University, Guiyang 550025, China; ²School of Environmental and Safety Engineering, Changzhou University, Changzhou, Jiangsu 213164, China

Corresponding author: HE Jun-Yu; E-mail: junyuhe0303@sina.com, gzdx2006@126.com

Abstract:

In order to explore the ameliorating role of hydrogen peroxide (H₂O₂) on inhibition of seed germination caused by cadmium, the effects of different H₂O₂ concentration on seed germination, seeding growth and physiological characteristics of rice (‘Zhongyou No. 169’) were studied under 200 μmol·L^-1 cadmium stress. The results showed that 200 μmol·L^-1 cadmium stress inhibited rice seed germination and seeding growth. Germination potential, germination index, vigor index, root length, shoot length and soluble protein content were decreased significantly. MDA content and POD activity were increased significantly, However, the activities of SOD, APX and CAT were inhibited obviously. Low concentration of H₂O₂ (≤10 μmol·L^-1) could alleviate the inhibition effects of cadmium, and the germination index, vigor index, root length, shoot length, root and shoot fresh weight, the activities of SOD, POD and APX of rice seedlings increased and the MDA content was significantly inhibited. The seed germination and seeding growth of rice under cadmium stress can be significantly improved by soaking 5 μmol·L^-1 H₂O₂. However, the mitigation effect of cadmium stress is gradually weakened with the increase of hydrogen peroxide concentration, and 50 μmol·L^-1 H₂O₂ will aggravate the toxicity of cadmium stress. The appropriate concentration of hydrogen peroxide can improve the antioxidant ability of rice seedlings, promote rice growth and alleviate cadmium stress injury.

Key words: rice; cadmium; hydrogen peroxide; seed germination; physiological characteristics