外源EBR对NaCl胁迫下燕麦幼苗无机离子吸收、运输和分配的影响

为了探讨外源2,4-表油菜素内酯(2,4-epibrassinolide,EBR)诱导燕麦(Avena sativa L.)幼苗抗盐性的效果及其生理调节机制,以"青引2号"和"加燕2号"燕麦为材料,研究NaCl胁迫下施用外源EBR对燕麦幼苗无机离子吸收、运输和分配的影响。结果表明:100mmol·L-1NaCl胁迫下,"青引2号"和"加燕2号"燕麦幼苗叶片和根系中的Na+、Cl-含量均显著升高,对阳离子的吸收产生了拮抗作用,导致燕麦幼苗叶片和根系中的K+、Ca2+、Mg2+、Mn2+、Fe2+、Zn2+、Cu2+含量显著降低,离子稳态平衡被打破;100 mmol·L-1NaCl胁迫下,施用0.01μmol·L-1外源EBR后,"青引2号"和"加燕2号"燕麦幼苗叶片和根系中的Na+和Cl-含量显著降低,促进了燕麦幼苗根系对K+、Ca2+、Mg2+、Fe2+、Mn2+、Cu2+和Zn2+的吸收,叶片和根系中K+/Na+、Cl-/Na+、Ca2+/Na+、Mg2+/Na+、Fe2+/Na+、Mn2+/Na+、Cu2+/Na+和Zn2+/Na+显著升高,并且有效调控燕麦幼苗体内无机离子的运输比和阳离子的运输选择性比率,离子稳态重新达到平衡状态;说明外源EBR能够缓解NaCl胁迫下Na+和Cl-对燕麦幼苗所造成的离子毒害作用,有效调控燕麦幼苗对无机离子的选择性吸收、运输和分配,对维持燕麦幼苗体内的离子稳态平衡具有正向调控作用。

Effects of exogenous 2,4-epibrassinolide on the absorption,transportation and allocation of inorganic ions in Avena sativa L. seedlings under NaCl stress.

To investigate the induction effect of exogenous 2,4-epibrassinolide(EBR)on salt resistance of oat seedlings and reveal the potential physiological mechanism,we examined the effects of EBR on the absorption,transportation,and allocation of inorganic ion in oat seedlings under NaCl stress,with Avena sativa cv.‘Qingyin No.2’and cv.‘Jiayan No.2’as materials.Results showed that under 100 mmol·L-1 NaCl stress,the content of Na+and Cl-in leaf and root of‘Qingyin No.2’and‘Jiayan No.2’seedlings increased significantly.NaCl stress had antagonistic effects on cationic absorption,with reductions of contents of K+,Ca2+,Mg2+,Fe2+,Mn2+,Cu2+,and Zn2+as well as a disordered ion equilibrium in leaf and root of oat seedlings.Under 100 mmol·L-1 NaCl stress,the addition of 0.01μmol·L-1 EBR significantly reduced the content of Na+and Cl-in leaf and root of‘Qingyin No.2’and‘Jiayan No.2’seedlings,while the absorption of K+,Ca2+,Mg2+,Fe2+,Mn2+,Cu2+,and Zn2+was improved,and the ratios of K+/Na+,Cl-/Na+,Ca2+/Na+,Mg2+/Na+,Fe2+/Na+,Mn2+/Na+,Cu2+/Na+,and Zn2+/Na+were increased significantly;the transport ratio of inorganic ions and the transport selectivity ratio of cations were effectively regulated,and the steady state of ion recovered.Our results suggestthat exogenous EBR could alleviate the toxicity of Na+and Cl-to oat seedlings under Na Cl stress and effectively regulating the selective absorption,transportation,and allocation of inorganic ions in oat seedlings,with a positive regulatory effect on ion steady-state equilibrium in oat seedlings.