外源5–氨基乙酰丙酸促进苹果叶片气孔开放机理的初探

Preliminary Studies on the Possible Mechanism Underlying 5-aminolevulinic Acid-induced Stomatal Opening in Apple Leaves

以‘富士’苹果离体叶片下表皮组织为材料,借助药剂处理、光学显微镜和激光扫描共聚焦显微镜(LSCM),研究了外源5–氨基乙酰丙酸(5-ALA)促进气孔开放效应及其可能机制。结果表明,5-ALA能够促进光、暗条件下苹果叶片气孔开放,阻止外源ABA和H2O2诱导的气孔关闭,还能逆转Ca2+诱导的气孔关闭。5-ALA处理后,苹果叶片保卫细胞内源H2O2和Ca2+含量显著下降。根据这些结果推测,5-ALA可以通过下调苹果叶片保卫细胞H2O2和Ca2+含量来促使气孔开放。

A possible mechanism for 5-aminolevulinic acid(5-ALA)to promote stomatal aperture was studied with abaxial epidermis of detached leaves of apple(Malus × domenstica Korkh.‘Fuji')combined with pharmacology,microscopy and laser-scanning confocal microscopy. It was found that 5-ALA promoted stomata opening under both light and dark conditions. It also inhibited the stomata closure induced by exogenous ABA and H2O2,and reversed the closure by Ca2+. Furthermore,5-ALA treatment was found to reduce the endogenous H2O2 and Ca2+ content in guard cells of apple leaves. Therefore,it can be deduced that 5-ALA induced stomata opening may be the result of down-regulation of H2O2 and Ca2+ content in the guard cells of apple leaves.