Methyl Jasmonate and Nitric Oxide in Regulation of the Stomatal Apparatus of Arabidopsis thaliana

The effect of methyl jasmonate, donors and antagonists of nitric oxide (NO) on the state of stomata of Arabidopsis thaliana plants (Col-0) was studied. Treatment of the epidermis of leaves with a 50-400 M solution of methyl jasmonate (MJ) caused a decrease in the size of the stomatal aperture and the percentage of open stomata. These effects were completely eliminated after preliminary treatment of epidermis cells with NO scavenger PTIO (2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) and partially after treatment with inhibitors of animal NO synthase (N-G-nitro-L-arginine methyl ester, L-NAME) and nitrate reductase (sodium tungstate). NO donors (L-arginine and sodium nitrite) in concentrations of 0.5-2.0 mM also caused a decrease in the number of open stomata and the size of the stomatal aperture. The action of L-arginine on the state of stomata was leveled by pretreatment of cells with L-NAME, and effects of sodium nitrite were eliminated by preaction of sodium tungstate. A conclusion about the possible participation of nitrogen oxide, forming both as the result of L-arginine oxidation and during nitrate/nitrite reduction, in the regulation of the stomatal apparatus and about its role in the realization of an MJ effect on state of stomata in Arabidopsis thaliana was made.