Involvement of Endogenous Abscisic Acid in Methyl Jasmonate-Induced Stomatal Closure in Arabidopsis

• Published in: Plant physiology (Bethesda) 2011-05, Vol.156 (1), p.430-438
• Main Authors: Hossain, Mohammad Anowar, Munemasa, Shintaro, Uraji, Misugi, Nakamura, Yoshimasa, Mori, Izumi C., Murata, Yoshiyuki
• Format: Article
• Language: English
• Subjects: Abscisic Acid - metabolism; Acetates - pharmacology; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biological and medical sciences; Calcium - metabolism; CELL BIOLOGY AND SIGNAL TRANSDUCTION; Cyclopentanes - pharmacology; Dioxygenases - genetics; Dioxygenases - metabolism; Endopeptidases - genetics; Endopeptidases - metabolism; Fundamental and applied biological sciences. Psychology; Herbicides - pharmacology; Mutation; Oxylipins - pharmacology; Plant Growth Regulators - metabolism; Plant Growth Regulators - pharmacology; Plant Leaves - drug effects; Plant Leaves - genetics; Plant Leaves - physiology; Plant physiology and development; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Stomata - drug effects; Plant Stomata - genetics; Plant Stomata - physiology; Pyridones - pharmacology; Signal Transduction - drug effects
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.111.172254

In this study, we examined the involvement of endogenous abscisic acid (ABA) in methyl jasmonate (MeJA)-induced stomatal closure using an inhibitor of ABA biosynthesis, fluridon (FLU), and an ABA-deficient Arabidopsis (Arabidopsis thaliana) mutant, aba2-2. We found that pretreatment with FLU inhibited MeJA-induced stomatal closure but not ABA-induced stomatal closure in wild-type plants. The aba2-2 mutation impaired MeJA-induced stomatal closure but not ABA-induced stomatal closure. We also investigated the effects of FLU and the aba2-2 mutation on cytosolic free calcium concentration ([Ca²⁺] cyt ) in guard cells using a Ca²⁺-reporter fluorescent protein, Yellow Caméléon 3.6. In wild-type guard cells, FLU inhibited MeJA-induced [Ca²⁺] cyt elevation but not ÁÂÁ-induced [Ca²⁺] cyt elevation. The aba2-2 mutation did not affect ABA-elicited [Ca²⁺] t elevation but suppressed MeJA-induced [Ca²⁺] cyt elevation. We also tested the effects of the aba2-2 mutation and FLU on the expression of MeJA-inducible VEGETATIVE STORAGE PROTEIN1 (VSP1). In the aba2-2 mutant, MeJA did not induce VSP1 expression. In wild-type leaves, FLU inhibited MeJA-induced VSP1 expression. Pretreatment with ABA at 0.1 μm, which is not enough concentration to evoke ABA responses in the wild type, rescued the observed phenotypes of the aba2-2 mutant. Finally, we found that in wild-type leaves, MeJA stimulates the expression of 9-CIS-EPOXYCAROTENOID DIOXYGENASE3, which encodes a crucial enzyme in ABA biosynthesis. These results suggest that endogenous ABA could be involved in MeJA signal transduction and lead to stoma tal closure in Arabidopsis guard cells.