NaCl胁迫对盐芥和拟南芥K^+、Na^+吸收的影响(简报)

Compare of K^+ and Na^+ content absorption in leaves and roots of Thellungiella halophila and Arabidopsis thaliana under NaCl stress

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.