盐胁迫下苗期栽培大豆生理响应及Na^+动态平衡关键基因的表达  

Effect of Salt Stress on Physiological Reponses and the Expression of Key Genes Involved in Na^+ Homeostasis of Soybean Seedlings

作　　者：宁丽华[1] 张大勇[1] 刘佳[1] 何晓兰[1] 万群[1] 徐照龙[1] 黄益洪[1] 邵宏波[1] 

机构地区：[1]江苏省农业科学院农业生物技术研究所/江苏省农业生物学重点实验室,南京210014

出　　处：《中国农业科学》2016年第24期4714-4725,共12页Scientia Agricultura Sinica

基　　金：国家自然科学基金(31600211;31101166);江苏省自然科学基金(BK20160584);江苏省农业科技自主创新资金(CX(15)1005);江苏省农业三新工程(SXGC(2016)335)

摘　　要：【目的】研究耐盐栽培大豆和盐敏感栽培大豆对盐胁迫的响应,特别是盐胁迫对大豆幼苗光合特性、离子含量及Na^+动态平衡相关基因表达的影响,通过比较盐胁迫下不同大豆品种的响应差异,揭示不同基因型大豆耐盐机制,为大豆栽培管理、耐盐品种的选育及人工调控提供理论参考。【方法】以耐盐栽培大豆(Y8D6008、Y8D6013)和盐敏感栽培大豆(Y8D6132、Y8D6136)为材料,选取长势一致的大豆幼苗于1/2×Hoagland营养液中培养,待第一片复叶完全展开时,营养液中加入Na Cl,每天递增50 mmol·L^(-1)到达处理浓度150 mmol·L^(-1),处理持续7 d。以不加Na Cl的1/2×Hoagland营养液作为对照,研究盐胁迫下大豆幼苗的光合特性、离子含量及Na^+动态平衡相关基因表达变化。【结果】150 mmol·L^(-1) Na Cl不同程度地抑制了4种大豆幼苗生长,同时显著降低SPAD值、净光合速率、气孔导度和蒸腾速率,但是Na Cl胁迫对盐敏感大豆影响程度显著高于耐盐品种;盐胁迫显著降低耐盐大豆的胞间CO2浓度,而盐敏感大豆与之相反,说明150 mmol·L^(-1) Na Cl处理下气孔限制是引起耐盐品种光合速率下降主要因素,而盐敏感品种光合速率下降主要因素是非气孔限制。对大豆植株的不同离子含量进行测定,发现盐胁迫下4种大豆叶片中Na^+积累均显著升高,盐敏感品种上升幅度显著高于耐盐品种,而K^+含量与Na^+含量的变化规律相反。盐敏感大豆叶片中磷含量(P)均受盐胁迫显著下降,而耐盐大豆叶片P在胁迫后略有增加。相关分析表明净光合速率变化幅度与叶片中Na^+、K^+和P含量变化幅度存在显著的相关性。对6个参与大豆植株体内Na^+动态平衡相关基因Gm SOS1、Gm Ncl1、Gm SALT3、Gm NHX1(离子通道基因)、Gm CIPK1(信号转导基因)和Gm AVP1(能量运输相关基因)相对表达量进行分析,发现盐胁迫后4种大豆的Gm Ncl1表达量均显著上调,盐敏感品�【Objective】In order to provide a reference for soybean cultivation,breeding and artificial regulation of salt stress,the physiological and molecular responses to different genotype soybean seedlings,especially the effects of salt stress on photosynthetic parameters,ions content and the expression of key genes involved in Na~＋ homeostasis of soybean seedlings were studied.Through comparison of the difference in response to salt stress,the study try to reveal the salt resistance mechanisms of different cultivated genotypic soybeans.【Method】The responses of photosynthetic characteristics and ion content of soybean seedlings were studied under salt stress.Salt tolerant cultivated soybean varieties（Y8D6008,Y8D6013） and salt sensitive cultivated soybean varieties（Y8D6132,Y8D6136） were incubated in the 1/2×Hoagland nutrient solution.Na Cl was added to nutrient solution incrementally by 50 mmol·L^-1 step per day to provide final concentrations of 150 mmol·L^-1 for salt treatment at 1-compound leaf stage,and the treatment lasted for 7 days.The control plants were cultured with nutrient solution without adding Na Cl.The response of soybean seedlings to Na Cl stress was assessed by measuring the expression of key genes involved in Na~＋ homeostasis,photosynthetic parameters,and the ion content of soybean.【Result】The growth of the four cultivated soybean seedlings was significantly inhibited by 150 mmol·L^-1 Na Cl stress.And salt stress significantly reduced soybean leaf SPAD value,net photosynthetic rate and transpiration rate.However,the inhibition of Na Cl on growth and photosynthetic characteristics was more severe in salt sensitive cultivar than in salt tolerant cultivar.Moreover,150 mmol·L^-1 Na Cl concentration reduced leaf intercellular CO2 concentration in salt tolerant cultivar,and increased it in salt sensitive cultivar.Thus,the reduction in net photosynthesis rate of salt tolerant cultivar caused by 150 mmol·L^-1 Na Cl stress was considered to be a result of stomatal restriction;but i

关 键 词：栽培大豆 盐胁迫 光合特性 离子含量 基因表达 Na^+动态平衡 

分 类 号：S565.1[农业科学—作物学]