Guard cell-specific inhibition of Arabidopsis MPK3 expression causes abnormal stomatal responses to abscisic acid and hydrogen peroxide

• Autores: Gudesblat, G.E.; Iusem, N.D.; Morris, P.C.
• Año de publicación: 2007
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: New Phytol. 2007;173(4):713-721
• Materia: Abscisic acid (ABA); Arabidopsis thaliana; Hydrogen peroxide (H 2O2); MAP kinase; MPK3; Stomata; abscisic acid; Arabidopsis protein; complementary DNA; hydrogen peroxide; mitogen activated protein kinase 3; abnormality; abscisic acid; alkalinization; enzyme activity; gene expression; hydrogen peroxide; inhibition; RNA; signal; stomatal conductance; transgenic plant; Arabidopsis; article; cytology; genetic transformation; genetics; metabolism; physiology; plant epidermis; plant leaf; signal transduction; transgenic plant; Abscisic Acid; Arabidopsis; Arabidopsis Proteins; DNA, Antisense; Hydrogen Peroxide; Mitogen-Activated Protein Kinase 3; Plant Epidermis; Plant Leaves; Plants, Genetically Modified; Signal Transduction; Transformation, Genetic; Arabidopsis; Arabidopsis thaliana
• Institución: Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales

MAP kinases have been linked to guard cell signalling. Arabidopsis thaliana MAP Kinase 3 (MPK3) is known to be activated by abscisic acid (ABA) and hydrogen peroxide (H2O2), which also control stomatal movements. We therefore studied the possible role of MPK3 in guard cell signalling through guard cell-specific antisense inhibition of MPK3 expression. Such transgenic plants contained reduced levels of MPK3 mRNA in the guard cells and displayed partial insensitivity to ABA in inhibition of stomatal opening, but responded normally to this hormone in stomatal closure. However, ABA-induced stomatal closure was reduced compared with controls when cytoplasmic alkalinization was prevented with sodium butyrate. MPK3 antisense plants were less sensitive to exogenous H2O2, both in inhibition of stomatal opening and in promotion of stomatal closure, thus MPK3 is required for the signalling of this compound. ABA-induced H2O2 synthesis was normal in these plants, indicating that MPK3 probably acts in signalling downstream of H2O2. These results provide clear evidence for the important role of MPK3 in the perception of ABA and H 2O2 in guard cells. © The Authors (2007).
Fil:Gudesblat, G.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Iusem, N.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.