Effects of Foliar and Root Applications of Methanol on the Growth of Arabidopsis, Tobacco, and Tomato Plants

The effects of aqueous methanol solutions applied as a foliar spray or via irrigation were investigated in Arabidopsis, tobacco, and tomato plants. Methanol applied to roots leads to phytotoxic damage in all three species tested. Foliar application causes an increase of fresh and dry weight in Arabidopsis and tobacco plants, but not in tomato plants. The increase in fresh and dry weight of Arabidopsis plants does not correlate with increased levels of soluble sugars, suggesting that increased accumulation of other products is responsible for the differences in the methanol-treated leaves. Foliar application of methanol can induce pectin methylesterase (PME) gene expression in Arabidopsis and tomato plants, activating specific PME genes.