摘要
盐胁迫下植物对K+和Na+的选择性吸收能够代表植物对盐胁迫的适应性。本研究以盐生植物盐芥和甜土植物拟南芥为材料,研究了NaCl胁迫下盐芥和拟南芥幼苗的生长,K+、Na+在根与叶中的含量。结果表明,叶中拟南芥Na+含量逐渐增加,K+含量逐渐减少,K+/Na+逐渐降低;盐芥则完全不同,盐浓度从0逐渐增加到300mmol/L,Na+含量基本没有变化,K+含量先增加然后逐渐减少,K+/Na+先升高然后逐渐降低,100和200 mmol/LNaCl胁迫下,盐芥的K+/Na+分别比拟南芥的高2和5倍。随着NaCl浓度从0逐渐增加到200 mmol/L,盐芥和拟南芥根中Na+和K+的增加和降低趋势相同,盐芥K+的含量随着盐浓度的增加先增加随后逐渐降低,拟南芥K+的含量逐渐降低,相同浓度下根的K+/Na+始终是盐芥高于拟南芥。盐芥表现出盐生植物吸钾拒钠的特性。SNa+/K+值表明盐芥限制地上部分吸收Na+的能力比拟南芥更强。分析结果发现盐胁迫下拟南芥中的Na+与K+含量变化极显著正相关,因此推断它们的吸收通道或载体为单一竞争性。盐芥吸收的Na+与K+含量完全不相关,具有各自独立的载体或通道系统。
The ability to selectively absorb K^+ and Na^+ by Thellungiella halophila can represent its salt tolerance. In this study we stressed T. halophila and Arabidopsis thaliana seedlings with 0- 300 mmol/L NaC1 so lution for 48 h,and K^+ ,Na^+ content in roots and leaves of T. halophila and A. thaliana were determined. The result showed:When NaC1 concentration was increased from 0 to 300 mmol/L, the Na^+ percentage in A. thaliana leaves increased while K^+ percentage decreased sharply and the value of K^+/Na^+ decreased gradually. T. halophila was completely different and with the increased NaC1 concentration, the Na^+ percentage did not change. At first the K^+ percentage increased but then dropped off so the value of K^+/Na^+ increased initially and then gradually decreased. In 100 and 200 mmol/L NaCl stress the K^+/Na^+ value in T. halophila were 2 and 5-fold higher respectively than those in A. thaliana. In roots, the increased Na^+ content and decreased K^+ gave similar results in both T. halophila and A. thaliana. Compared with A. thaliana, the T. halophila selectively absorbed the K^+ but resisted the Na^+. An analysis of these results, showed that the positive correlations of Na^+ and K^+ content in A. thaliana were significant, but they were not correlated in T. halophila, so the Na^+ and K^+ channels in A. thaliana were linked together, but there was no correlation between Na^+ and K^+ content in T. halophila indicating that the Na^+ and K^+ channels or carriers were different.
出处
《草业学报》
CSCD
2007年第4期21-24,共4页
Acta Prataculturae Sinica
基金
中国科学院百人计划和寒区旱区环境与工程研究所科研基金资助