盐胁迫条件下提高内源乙烯对拟南芥幼苗生长和根尖活性氧水平的影响

以模式植物拟南芥（Arabidopsis thaliana）为材料，研究了内源乙烯对幼苗耐盐性的影响。研究结果表明，在施加了浓度为100 mmol·L^-1的NaCl胁迫的基质环境中，野生型拟南芥幼苗的根长和根重都显著减小。在施加外源乙烯利后不仅能够缓解盐胁迫对幼苗根伸长生长的抑制作用，而且能够缓解盐胁迫对幼苗根增重生长的抑制作用。施加外源ACC则只能缓解盐胁迫对幼苗根增重生长的抑制作用，而不能缓解盐胁迫对根的伸长生长的抑制。此外，100 mmol·L^-1 NaCl的胁迫条件下，拟南芥幼苗根尖中ROS水平明显升高，而施加了乙烯利和ACC处理下，幼苗根尖ROS的水平在NaCl胁迫下并没有明显的升高，说明内源乙烯可以调控植物体内的ROS维持在正常的水平，使植物体免受氧化损伤，从而提高了幼苗耐盐性。

Effects of Increased Endogenous Ethylene on Plant Salt Tolerance in Arabidopsis Seedlings under Saline Condition

The effects of endogenous ethylene on plant salt tolerance in Arabidopsis seedlings in exposure to salinity were investigated in the present work. The results showed that 100 mmol·L^-1 NaCl significantly decreased seedling root elongation and root fresh weight. Application of exogenous ethephon obviously alleviated salt-induced inhibition of root length and biomass accumulation. Comparatively, exogenous ACC had a positive effect merely on alleviating root weight inhibition caused by salt stress. The root ROS level in salt-stressed seedlings was also increased drastically, and both ethephon and ACC could keep the root ROS level at a low level as control under NaCl stress conditions. It was proposed that improvement of Arabidopsis salt tolerance induced by ethylene is tightly related to root redox state.