野大麦耐盐适应性反应机制的研究  

Adaptive Mechanisms of Salt Tolerance in Hordeum brevisubulatum

作　　者：李瑞芬[1] 王雪青[1] 王宏芝[1] 魏建华[1] 

机构地区：[1]北京市农林科学院北京农业生物技术研究中心,北京100089

出　　处：《中国农业科学》2006年第12期2459-2466,共8页Scientia Agricultura Sinica

基　　金：国家自然科学基金项目(30370856)资助

摘　　要：目的探讨野大麦的耐盐适应性反应机制。方法采用原子吸收和X-ray微区分析等方法分析野大麦[Hordeumbrevisubulatum(Trin.)Link]在NaCl胁迫下幼苗生长、K+和Na+吸收、运输、分配及外排等生理响应。结果在NaCl≤350mmol·L-1时,茎叶和根系的干重变化不明显,盐浓度的增加对根生长的抑制作用小于茎叶,根Na+含量增加的幅度小于茎叶、茎叶和根中K+含量均下降,但茎叶可维持较高的K+含量;野大麦具有较强的K+-Na+吸收选择性;低盐胁迫时Na+主要贮存于液泡和细胞间质;高盐胁迫时主要通过外排Na+来维持体内离子平衡。结论野大麦在NaCl≤350mmol·L-1时生长正常,其耐盐性与根拒绝吸收Na+及茎叶维持高K+含量有关,Na+区域化与外排可能是野大麦主要的耐盐适应性反应机制。[ Objective l The objective was to study adaptive mechanisms of salt tolerance in H. brevisubulatum [ Method ] The methods such as atom absorption and X-ray microanalysis were used to investigate the responses for seedling growth, regulation of Na^＋ and K^＋ uptake and transport to shoot, ion compartmentation and Na^＋ efflux in saline conditions. [ Result ]The dry mass of shoots and roots had no significant difference in the range of 350 mmol·L^-1 NaCI stress, and NaCl stress inhibited the growth of shoot more severely than that of root. The increment of Na^＋ content in root was more than that in shoot, K^＋ contents in shoot and root were all decreased, but shoot could maintained higher K^＋ level, the higher K^＋/Na^＋ resulted from the higher K^＋-Na^＋ selectivity of plasma membrane. X-ray microanalysis indicated Na^＋ in cytoplasm was compartmented into vacuole and apoplast under salt stress with lower concentration. Na^＋ efflux out of shoot was the main path way of ion homeostasis under salt stress with higher concentration. [Conclusion] Plants grew normally when NaCI concentration was less than 350 mmol·L^-1, H. brevisubulatum tended to take up less Na^＋ and maintain higher K^＋ in the shoot, Na^＋ compartmentation and efflux out of shoot were the adaptive key mechanisms of salt tolerance in H. brevisubulatum

关 键 词：野大麦 NACL胁迫 耐盐 离子区域化 离子外排 

分 类 号：S512.3[农业科学—作物学]