NaCl胁迫对盐生植物长叶红砂幼苗内源激素的影响

Effects of NaCl Stress on the Content of Endogenous Hormones in Reaumuria trigyna Seedling

盐生植物长叶红砂为东阿拉善-西鄂尔多斯特有种,古地中海残遗珍稀植物,对盐渍荒漠具有极强的适应性.以培养条件下的长叶红砂为材料,研究不同浓度NaCl胁迫处理对长叶红砂幼苗内源激素的影响.结果表明:在盐浓度≤60mmol/L时,随着盐胁迫浓度的增加,ABA含量呈逐渐增加趋势,在80mmol/L取得最小值之后又逐渐增加;IAA、ZR、GA3表现为先升高后降低的趋势,均在60mmol/L处理时取得最大值.长叶红砂(IAA+ZR+GA3)/ABA比值和相对生长率随NaCl浓度增加均呈现先升高后降低的趋势,并均在80mmol/L时达到最大值.推测80mmol/L NaCl浓度是长叶红砂幼苗生长的最适浓度.因长叶红砂长期生长在盐生环境中,已经进化出对盐生环境的内部适应机制,盐胁迫下内源激素的综合调控对长叶红砂的生长发育起到至关重要的作用.

Reaumuria trigyna, a rare plant relic speces derived from the Paleo--Tethys Ocean,is peculiarly endemic to Alax-Erdos desert of China. It is well adapted to salty deserted land. Solutions of different concentrations of NaCl were used for saline stress of Reaumuria trigyna to measure and analyse the content of endogenous hormones in the leases of seedlings. The results showed the following： with the increasing concentration of salt stress from 0 to 60 mmol/L, ABA content increased gradually. At 80mmol/L salt stress,ABA content fell sharply and tumbled to its lowest level,then ABA content increased again. The tendency of the contents of IAA, ZR and GA3 were the same,which rose firstly and then descended, both achieved the maximum processed at 60mmol/L. The tendency of （IAA＋ZR＋GA3） /ABA ratio and relative growth rate all increased first then decreased, and reached the maximum when NaC1 concentration was 80mmol/L. It is speculated that the optimal concentration for seedling growth is 80mmol/L. Due to long-term growth in saline environment,Reaumuria trigyna has developed an internal adaptive mechanisms for salt stress. Integration regulation of endogenous hormone plays a key role for Reaumuria trigyna growth under salt stress.