NaCl胁迫对盐芥和拟南芥K+、Na+吸收的影响(简报)

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。

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

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 NaCl solution for 48 h,and K ,Na content in roots and leaves of T.halophila and A.thaliana were determined.The result showed:When NaCl 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 NaCl 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.