草业学报2016，Vol.25Issue(4)：91-103,13.DOI:10.11686/cyxb2015289
外源2，4-表油菜素内酯对NaCl胁迫下紫花苜蓿幼苗光合特性及离子吸收、运输和分配的影响
Effect of exogenous 2,4-epibrassinolide on the uptake,transport,and disputation of ions,and photosynthetic characteristics of Medicago sativa seedlings under NaCl stress
摘要
Abstract
The aim of this study was to explore the salt resistance and physiological regulation mechanisms in-duced by exogenous 2,4-epibrassinolide (EBR)in alfalfa (Medicago sativa )seedlings.The effect of EBR on photosynthetic pigment contents,gas exchange parameters,and ion uptake,transport,and disputation in seedlings of M.sativa cv.Zhongmu No.3 and M.sativa cv.Longzhong under NaCl stress were investigated u-sing a hydroponic method.In the 150 mmol/L NaCl stress treatment,alfalfa seedling leaves showed significant decreases in photosynthetic pigment contents and photosynthetic ability,and disrupted metabolic processes of ion uptake,transport,and disputation.When EBR at 0.1 μmol/L was supplied to seedlings under NaCl stress, the chlorophyll a,b,and a+b contents increased,the chlorophyll a/b increased,and the chlorophyll/carote-noid decreased.Also,the photosynthetic rate,transpiration rate,stomatal conductance,water use efficiency, and photosynthetic ability increased after 0.1 μmol/L EBR treatment.These changes would facilitate the accu-mulation of aboveground and underground biomass.In the NaCl-stressed seedlings treated with 0.1 μmol/L EBR,the Na+ and Cl- contents and the Cl-/Na+ in different organs (leaf,stem,and root)significantly de-creased,and the contents of K+ ,Ca2 + ,and Mg2 + and the K+/Na+ ,Ca2 +/Na+ ,and Mg2 +/Na+ significantly increased.The transport ratio of inorganic ions and transport selectivity ratio of cations were effectively regula-ted in the seedlings treated with EBR.Together,these results show that EBR treatment effectively alleviated photo inhibition caused by NaCl stress in alfalfa seedlings,and promoted the synthesis and accumulation of or-ganic matter.Treatment with EBR also improved the selective absorption and transport of inorganic ions,help-ing to maintain the metabolic ion balance and improve the NaCl-resistance of alfalfa seedlings.关键词
紫花苜蓿/NaCl 胁迫/2,4-表油菜素内酯/光合作用/离子代谢Key words
Medicago sativa/NaCl stress/2,4-epibrassinolide/photosynthesis/ion metabolism引用本文复制引用
寇江涛,康文娟,苗阳阳,师尚礼..外源2，4-表油菜素内酯对NaCl胁迫下紫花苜蓿幼苗光合特性及离子吸收、运输和分配的影响[J].草业学报,2016,25(4):91-103,13.基金项目
国家现代牧草产业技术体系建设专项（CARA-35）和全国种质资源保种（NB2130135）资助。 （）
