In order to compare the effects of methanol and ethanol application on plant physiological characters,5% (V/V) methanol and ethanol were sprayed,respectively,on the leaves of Rohdea japonica grown under greenhouse conditions twice a week,with plants sprayed distilled water as the control.After three weeks,the effects of foliar spraying methanol and ethanol on plant growth,physiological characters and the gene expression related photosynthesis were analyzed.These results indicated that methanol and ethanol both increased leaf fresh weight,total leaf soluble protein content,stomatal conductance,transpiration rate,intercellular CO₂ concentration,net photosynthetic rate,chlorophyll a,b content and total chlorophyll content;decreased leaf hydrogen peroxide content;increased plasma membrane H⁺-ATPase and H⁺-pump activity and the effects of ethanol were more significant than those of methanol.RT-PCR showed that at 12 h methanol stimulation repressed the transcription of genes encoding light-harvesting chlorophyll a/b binding protein (Cab) and Ferredoxin-2 (2-FdO),ethanol stimulation induced their expressions,while up-regulated by methanol and down-regulated by ethanol at 72 h after spraying;both methanol and ethanol induced the transcription of gene encoding the photosystem Ⅱ reaction center PsbP family protein (PsbP).According to these data,it can be inferred that the two kinds of alcohol may work as a signal molecule in plants,and the stimulating effect of ethanol is more significant than methanol.