关键词: 苹果, ALA, ABA, 黑暗, 乙烯, H2O2, 黄酮醇, 气孔运动

Abstract: In order to investigate the possible regulatory roles of the gaseous hormone ethylene in the inhibitory effect of ALA on ABA- or dark-induced stomatal closure，the stomatal aperture，ethylene production，H2O2 and flavonol levels in guard cells and gene expressions in the abaxial epidermis of detached apple（Malus × domestica Borkh.‘Fuji’）leaves were studied using pharmacology，gas chromatography，laser confocal scanning microscope，optical microscope and qRT-PCR techniques. The results showed that the ALA treatment promoted ethylene release，while both aminoethoxyvinylglycine （AVG），an ethylene biosynthetic inhibitor，and 1-methylcyclopropene（1-MCP），an ethylene receptor inhibitor，repressed the inhibitory effect of ALA on ABA or dark-induced stomatal closure. Exogenous ALA up-regulated expression of the genes related to ethylene biosynthesis and its signal transduction. AVG weakened the inhibition of ALA on ABA- and dark-induced H2O2 accumulation，as well as ALA-induced flavonol accumulation in guard cells. It can be concluded that ALA up-regulates gene expressions to induce ethylene biosynthesis and signal transduction，which positively regulate the flavonol accumulation to reduce the H2O2 content and promote the stomatal opening，benefiting CO2 entrance during photosynthesis.

Key words: apple, ALA, ABA, dark, ethylene, H2O2, flavonol, stomatal movement