Over-expression of the stress-induced OsWRKY45 enhances disease resistance and drought tolerance in Arabidopsis

• Published in: Environmental and experimental botany Vol. 65; no. 1; pp. 35 - 47
• Main Authors: Qiu, Yuping, Yu, Diqiu
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2009; Oxford; New York, NY: Elsevier Science; Elsevier
• Subjects: abiotic stress; Abiotic stress response; Abscisic acid; Arabidopsis; bacterial diseases of plants; biochemical pathways; Biological and medical sciences; desiccation (plant physiology); disease resistance; drought; Drought tolerance; Fundamental and applied biological sciences. Psychology; gene expression; gene expression regulation; gene overexpression; genetic resistance; Magnaporthe grisea; mannitol; Oryza sativa; OsWRKY45; pathogenesis-related proteins; plant pathogenic bacteria; plant stress; Pseudomonas syringae pv. tomato; Pseudomonas syringae tomato; Pyricularia oryzae; salt tolerance; seed germination; signal transduction; sodium chloride; stomata; transcription factors; transgenes; transgenic plants; water stress; Xanthomonas oryzae; Xanthomonas oryzae pv. oryzae; Abscisic acid; OsWRKY45; Abiotic stress response; Drought tolerance; Abiotic stress; Plant ecology; Tolerance; Arabidopsis thaliana; Response; Disease resistance; Cruciferae; Drought resistance; Dicotyledones; Sesquiterpenes; Angiospermae; Botany; Plant growth substance; Spermatophyta; Experimental plant
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/j.envexpbot.2008.07.002

The WRKY transcriptional factor superfamily regulates diverse functions, including processes such as plant development and stress response. In this study, we have shown that the rice WRKY45 ( OsWRKY45) expression is markedly induced in response to stress-related hormone abscisic acid (ABA) and various stress factors, e.g., application of NaCl, PEG, mannitol or dehydration, treatment with 0 °C and 42 °C as well as infection by Pyricularia oryzae Cav. and Xanthomonas oryzae pv. oryzae. Together, these results indicate that the OsWRKY45 may be involved in the signal pathways of both biotic and abiotic stress response. Further analyses of 35S: OsWRK45 Arabidopsis plants have shown that ectopic, constitutive over-expression of the OsWRKY45 transgene confers a number of properties to transgenic plants. These properties include significantly increased expression of PR genes, enhanced resistance to the bacterial pathogen Pseudomonas syringae tomato DC3000, enhanced tolerance to salt and drought stresses, decreased sensitivity toward ABA signalling during seed germination and post-germination processes, and modulation of ABA/stress-regulated genes during drought induction. In addition, higher levels of OsWRKY45 expression in transgenic plants correlate positively with the strength of the abiotic and biotic responses mentioned above. More specifically, the decreased ABA sensitivities, the enhanced disease resistance and drought tolerances may be attributed, in part, to stomatal closure and induction of stress-related genes during drought induction. The relationship between OsWRKY45 expression and ABA signalling is discussed.