Functional characterization of Arabidopsis thaliana WRKY39 in heat stress.
Arabidopsis thaliana WRKY39, a transcription factor that is induced by heat stress, is a member of the group II WRKY proteins and responds to both abiotic and biotic stress. Heat-treated seeds and plants of WRKY39 knock-down mutants had increased susceptibility to heat stress, showing reduced germination, decreased survival, and elevated electrolyte leakage compared with wild-type plants. In contrast, WRKY39 over-expressing plants exhibited enhanced thermotolerance compared with wild-type plants. RT-PCR and qRT-PCR analysis of wrky39 mutants and WRKY39 over-expressing plants identified putative genes regulated by WRKY39. Consistent with a role for WRKY39 in heat tolerance, the expression levels of salicylic acid (SA)-regulated PR1 and SA-related MBF1c genes were downregulated in wrky39 mutants. In contrast, over-expression of WRKY39 increased the expression of PR1 and MBF1c. The WRKY39 transcript was induced in response to treatment with SA or methyljasmonate. Analysis of heat stress-induced WRKY39 in defense signaling mutants, including coi1, ein2, and sid2, further indicated that WRKY39 was positively co-regulated by the SA and jasmonate (JA) signaling pathways. Together, these findings reveal that heat stress-induced WRKY39 positively regulates the cooperation between the SA- and JA-activated signaling pathways that mediate responses to heat stress.
Li
Shujia
S
College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
Zhou
Xiang
X
Chen
Ligang
L
Huang
Weidong
W
Yu
Diqiu
D
D000085:Acetates / Q000378:metabolism*; D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D018525:Germination / Q000235:genetics; D006358:Hot Temperature / Q000009:adverse effects; D019751:Intramolecular Transferases / Q000235:genetics; D046228:Microarray Analysis; D009154:Mutation / Q000235:genetics; D054883:Oxylipins / Q000378:metabolism*; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics; D011956:Receptors, Cell Surface / Q000235:genetics; D020156:Salicylic Acid / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D019076:Transgenes / Q000235:genetics
D000085:Acetates; D029681:Arabidopsis Proteins; C092776:CONSTANS protein, Arabidopsis; D003517:Cyclopentanes; D004268:DNA-Binding Proteins; C119963:EIN2 protein, Arabidopsis; C491466:MBF1 protein, Arabidopsis; D054883:Oxylipins; D010940:Plant Proteins; D011956:Receptors, Cell Surface; D015534:Trans-Activators; D014157:Transcription Factors; C553419:WRKY39 protein, Arabidopsis; C053376:pathogenesis-related proteins, plant; C072239:methyl jasmonate; D019751:Intramolecular Transferases; C058486:isochorismate synthase; D020156:Salicylic Acid