EBR对NaCl胁迫下苜蓿属植物离子吸收和分配的影响

Effects of epibrassinolide on ion absorption and distribution in Medicago species under NaCl stress

为探究苜蓿属植物的抗盐机理及外源油菜素内酯(EBR)对苜蓿属植物抗盐性的影响,选取蒺藜苜蓿、紫花苜蓿和金花菜3种苜蓿属植物为实验材料,研究NaCl胁迫及NaCl胁迫下喷施EBR对苜蓿属植物生长,体内无机离子吸收、分配及运输的影响。结果表明:1)NaCl胁迫会抑制苜蓿属植物的生长,影响植物体内K+、Ca2+、Mg2+离子的分配和运输。2)EBR能有效缓解NaCl胁迫对植物生长的抑制作用,维持植物体内的离子平衡,从而提高植物的耐盐性。3)紫花苜蓿耐盐性较强,蒺藜苜蓿耐盐性较弱。4)在盐胁迫条件下,紫花苜蓿根部抑制对Na+的吸收,减少离子毒害作用;蒺藜苜蓿将根中的Na+向茎和叶中运输,通过叶片的脱落,维持生长点的正常生长。

The aim of this study was to explore the mechanism of salt tolerance of Medicago species and the effect of exogenous brassinolide on salt tolerance of Medicago species.NaCl stress and the effects of epibrassinolide(EBR)on biomass,uptake,distribution and transport of Medicago species were studied under NaCl stress.Medicago truncatula,M.polymorphal and M.polymorpha were selected as experimental materials.The results show that NaCl stress inhibited the growth of Medicago plants and affect the distribution of K+,Ca2+,Mg2+in plants.EBR effectively relieved the inhibitory effect of NaCl stress on plant growth,maintaining ion balance in plants and improving tolerance to salt.Salt tolerance in M.sativa was strong whereas tolerance in M.truncatula was poor.Under salt stress,the roots of M.sativa inhibited the uptake of Na+to reduce the toxicity effects.M.truncatula transported Na+from roots to the stem and leaves.