Strawberry WRKY Transcription Factor WRKY50 Is Required for Resistance to Necrotrophic Fungal Pathogen Botrytis cinerea

WRKY protein is one of the largest plant-specific transcription factors that plays critical roles in plant stress responses, but few WRKY transcription factors have been functionally analyzed in strawberry. In this study, a Botrytis cinerea response WRKY gene, FvWRKY50, was isolated from the woodland strawberry. Expression analysis indicated that the transcript of FvWRKY50 was gradually decreased with fruit ripening, but was significantly induced by B. cinerea infection in mature strawberry fruit. Subcellular localization assay revealed that FvWRKY50 was localized in the nucleus. Several cis-elements related to pathogen responses were observed in the promoter region of FvWRKY50. Pathogen infection assay indicated that overexpression of FvWRKY50 in strawberry fruit significantly enhanced their resistance against B. cinerea, while the silencing of FvWRKY50 dramatically compromised their disease-resistant ability. The expression levels of several genes involved in jasmonic acid (JA) biosynthesis, signaling transduction, and antimicrobial protein biosynthesis were regulated to diverse extents in FvWRKY50 overexpressed and silenced fruit. Collectively, our study inferred that FvWRKY50 is a positive regulator that mediates resistance against B. cinerea through regulating some JA pathway and defense-related genes.

Heterologous expression of a plant WRKY protein confers multiple stress tolerance in E. coli Bir bitkinin heterolog ifadesi WRKY proteini çoklu stres yaratır E. coli’de tolerans

ObjectiveOsWRKY71, a WRKY protein from rice, is reported to function during biotic stresses. It is requisite to further enquire the efficiency and mechanism of OsWRKY71 under various environmental stresses. Stress indicators such as salt, cold, heat, and drought were studied by overexpressing the OsWRKY71 in E. coli.Materials and methodsDNA binding domain containing region of OsWRKY71 was cloned and expressed in E. coli followed by exposure to stress conditions. OsWRKY71 was also assessed for its role in abiotic stresses in rice by qPCR.ResultsRecombinant E. coli expressing OsWRKY71 was more tolerant to stresses such as heat, salt and drought in spot assay. The tolerance was further confirmed by monitoring the bacterial growth in liquid culture assay demonstrating that it encourages the E. coli growth under salt, drought, and heat stresses. This tolerance may be the consequence of OsWRKY71 interaction with the promoter of stress related genes or with other proteins in bacteria. The RT-qPCR analysis revealed the up-regulation of OsWRKY71 gene in rice upon interaction to cold, salt, drought and wounding with maximum up-regulation against salinity.ConclusionThus, the defensive role of OsWRKY71 may accord to the development and survival of plants during different environmental stresses.

FUNCTIONAL STUDY OF WRKY PROTEIN IN DIFFERENT PLANT AND NON-PLANT SPECIES AND ITS RESPONSE UNDER BIOTIC AND BIOTIC STRESSES

WRKY transcription factors belong to one of the biggest superfamilies of proteins in higher plants. WRKY proteins participate in plant growth for instance, gamete formation, seed germination and are also responsive to different types of environmental cues including abiotic and biotic stresses. The DNA-binding site of WRKY factors is well established which interact with W?box (TGACC(A/T)) located in the promoter of their target genes and promote the activation or repression of the expression of those genes to control their response against stresses but it remains difficult to establish the functions of every family members to control particular transcriptional programs during development or in response to environmental signals. This review summarizes the recent progress made in unraveling the various WRKY protein-controlled functions under different environmental stresses.

Genome-Wide Characterization, Expression Profile Analysis of WRKY Family Genes in Santalum album and Functional Identification of Their Role in Abiotic Stress

WRKY proteins are a large superfamily of transcription factors that are involved in diverse biological processes including development, as well as biotic and abiotic stress responses in plants. WRKY family proteins have been extensively characterized and analyzed in many plant species, including Arabidopsis, rice, and poplar. However, knowledge on WRKY transcription factors in Santalum album is scarce. Based on S. album genome and transcriptome data, 64 SaWRKY genes were identified in this study. A phylogenetic analysis based on the structures of WRKY protein sequences divided these genes into three major groups (I, II, III) together with WRKY protein sequences from Arabidopsis. Tissue-specific expression patterns showed that 37 SaWRKY genes were expressed in at least one of five tissues (leaves, roots, heartwood, sapwood, or the transition zone), while the remaining four genes weakly expressed in all of these tissues. Analysis of the expression profiles of the 42 SaWRKY genes after callus was initiated by salicylic acid (SA) and methyl jasmonate (MeJA) revealed that 25 and 24 SaWRKY genes, respectively, were significantly induced. The function of SaWRKY1, which was significantly up-regulated by SA and MeJA, was analyzed. SaWRKY1 was localized in the nucleus and its overexpression improved salt tolerance in transgenic Arabidopsis. Our study provides important information to further identify the functions of SaWRKY genes and to understand the roles of SaWRKY family genes involved in the development and in SA- and MeJA-mediated stress responses.

Genome- wide characterization, expression profile analysis of WRKY family genes in Santalum album and functional identification of their role in abiotic stress

Background: WRKY proteins are a large superfamily of transcription factors that are involved in diverse biological processes including development, as well as biotic and abiotic stress responses in plants. WRKY family proteins have been extensively characterized and analyzed in many plant species, including Arabidopsis , rice and poplar. However, knowledge on WRKY transcription factors in S antalum album is scarce. Results: Based on S . albu m genome and transcriptome data, 64 SaWRKY genes were identified in this study. A phylogenetic analysis based on the structures of WRKY protein sequences divided these genes into three major groups (I, II, III) together with WRKY protein sequences from Arabidopsis . Tissue-specific expression patterns showed that 37 SaWRKY genes were expressed in at least one of five tissues (leaves, roots, heartwood, sapwood, or the transition zone) while the remaining four genes were weakly expressed in all of these tissues. Analysis of the expression profiles of the 42 SaWRKY genes after callus was stimulated by salicylic acid (SA) and methyl jasmonate (MeJA) revealed that 34 and 19 SaWRKY genes, respectively were significantly induced. The function of SaWRKY1 , which was significantly up-regulated by SA and MeJA, was analyzed. SaWRKY1 was localized in the nucleus and its overexpression improved salt tolerance in transgenic Arabidopsis . Conclusions: Our study provides important information to further identify the functions of SaWRKY genes and to understand the roles of SaWRKY family genes involved in development and in SA- and MeJA-mediated stress responses.