NaCl胁迫对白刺幼苗体内游离态亚精胺和精胺含量的影响

以西伯利亚白刺试管苗为材料,研究其在0、50和200 mmol·L-1NaCl胁迫及外源环己胺调控下,生物量和体内多胺含量的改变,以探讨多胺对盐生植物白刺在盐胁迫下的生理调节功能.结果显示:50 mmol·L-1NaCl更有利于西伯利亚白刺的生长,处理后30 d白刺根系和地上部干重分别比对照增加75%和95%,处理15 d生根率比对照提高44.42%.而0(对照)和200 mmol·L-1NaCl都显著抑制白刺试管苗的生根与生长;200 mmol·L-1NaCl处理45 d时地上部干重比对照显著降低11.71%.白刺叶片中的多胺(精胺和亚精胺)含量随着盐浓度的增加呈降低趋势,茎和根中的多胺含量在200 mmol·L-1NaCl处理后才显著受到抑制;同时施环己胺和200 mmol·L-1NaCl处理使白刺叶片中的亚精胺含量显著低于200 mmol·L-1NaCl处理组,且叶绿素合成减少,细胞质膜透性增高.研究表明,西伯利亚白刺叶片内保持合适的多胺含量可能是其适应盐渍环境的重要机制之一.

Free Spermidine and Spermine Contents in Nitraria sibirica Pall.under Salt Stress

To explore the role of polyamines in the real halophytes under NaCl stress,we determined the biomass and contents of polyamine of Nitraria sibirica Pall.test-tube plantlets which have been growing under 0,50,200 mmol·L-1 NaCl stress and cyclohexylamine(CHA).It showed that,under the stress of 50 mmol·L-1 NaCl,N.sibirica Pall.test-tube plantlets grew best among three different salt concentrations.Shoot and root dry weight significantly increased by 75% and 95% under the 50 mmol·L-1 NaCl for 30 d,respectively;Rooting rate significantly increased by 44.42% for 15 d;the control and 200 mmol·L-1 NaCl significantly inhibited the growth of N.sibirica Pall.test-tube plantlets.Under the stress of 200 mmol·L-1 NaCl,shoot dry weight significantly decreased by 11.71% for 45 d.The polyamines(spermidine and spermine) contents in leaves were influenced significantly by salt stress and gradually decreased when NaCl stress intensified,however,the contents of polyamine in shoot and root were significantly inhibited only under 200 mmol·L-1 NaCl treatment;When CHA and 200 mmol·L-1 NaCl were added in culture medium,the content of spermidine was dramatically fewer than that with 200 mmol·L-1 NaCl stress only.At the same time,chlorophyll synthesis were inhibited and conductivity value increased.The appropriate content of polyamines in leaves of N.sibirica Pall.is one of adaption mechanism to salt environment.