《植物生理学报》 2018, 54(6): 991-998

干旱胁迫下外源茉莉酸甲酯对玉米幼苗根系吸水的影响

忽雪琦^1,2,#, 李东阳^1,#, 严加坤¹, 张岁岐^1,*

¹西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室, 陕西杨凌712100; ²西北农林科技大学林学院, 陕西杨凌712100

通信作者：张岁岐；E-mail: sqzhang@ms.iswc.ac.cn

摘　要：

茉莉酸类化合物作为环境信号分子, 不仅参与植物生长发育的调控, 同时受到环境胁迫的诱导, 参与植物对逆境胁迫的响应和防御。本研究以北方广泛种植的玉米品种‘郑单958’为材料, 通过对根系外源施加茉莉酸甲酯的方式, 探究干旱胁迫下茉莉酸甲酯对玉米幼苗抗旱性以及根系吸水的影响。结果表明, 外源茉莉酸甲酯可提高玉米幼苗光合速率、蒸腾作用和气孔导度, 增强抗氧化酶活性, 降低H₂O₂和丙二醛的含量, 从而缓解干旱胁迫对植株造成的损伤。通过测定根系水导、氯化汞处理的蒸腾速率的变化以及水通道蛋白的表达量, 发现干旱胁迫下外源茉莉酸甲酯可增强根系水通道蛋白的表达, 进而增强玉米幼苗的根系吸水能力, 从而缓解干旱胁迫造成的叶片水分含量的下降和水势的降低, 提高了玉米幼苗的抗旱性。

关键词：玉米; 茉莉酸甲酯; 干旱胁迫; 根系吸水能力

收稿：2018-04-10   修定：2018-05-18

资助：国家科技支撑计划(2015BAD22B01)。

Effects of exogenous methyl jasmonate on water absorption capacity of maize (Zea mays L.) seedling root under drought stress

HU Xue-Qi^1,2,#, LI Dong-Yang^1,#, YAN Jia-Kun¹, ZHANG Sui-Qi^1,*

¹State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China; ²College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China

Corresponding author: ZHANG Sui-Qi; E-mail: sqzhang@ms.iswc.ac.cn

Abstract:

Jasmonates, an environmental signal molecule, plays an important role not only in regulation of plant growth and development but also in plant response and defense to environmental stress. To investigate the effects of methyl jasmonate on drought tolerance and water absorption capacity of maize root at seedling stage, maize (Zea mays, ‘Zhengdan 958’) seedlings, which are widely planted in the north China, were used as experimental material in this study. The results showed that exogenous methyl jasmonate could promote the maize seedling photosynthetic rate, stomatal conductance and transpiration rate, increase the antioxidant enzyme activity, reduce the contents of H₂O₂ and MDA, and then alleviate the damage caused by drought stress. By investigating the root hydraulic conductance, the changes of the whole plant transpiration rate caused by HgCl₂ and the expression level of aquaporin, it was supposed that exogenous methyl jasmonate could increase aquaporins expression of root under drought stress, and enhance the water absorption capacity of root, to alleviate the decrease of leaf water content and leaf water potential. These results indicated that exogenous methyl jasmonate could improve the drought tolerance of maize seedlings through enhancing the root water uptake.

Key words: maize; methyl jasmonate; drought stress; water absorption capacity of root