Functional characterization of a WRKY transcription factor involved in the regulation of vacuolar transport and flavonoid biosynthesis
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ABSTRACT:
ORGANISM(S): Petunia x hybrida Vitis vinifera
PROVIDER: GSE86892 | GEO | 2017/03/10
SECONDARY ACCESSION(S): PRJNA342832
REPOSITORIES: GEO
Similar Datasets
Project description:The WRKY family represents a plant-specific class of zinc-finger transcription factors (TF) well known for regulating abiotic and biotic stress tolerance and also for their emergent role in the control of various developmental and physiological processes (Rushton et al. 2010, Schluttenhofer et al. 2015). The well-characterized AtTTG2, PhPH3 and BnTTG2 are ortholog WRKY proteins with interchangeable functions ascribed to an emergent clade whose regulatory functions are mainly associated with vacuolar metabolism (Li et al. 2015, Verweij et al. 2016, Gonzalez et al. 2016). In particular, PH3 of Petunia hybrida and TTG2 of Arabidopsis thaliana both act in the control of vacuolar pH and trafficking influencing the deposition of secondary metabolites in the petal epidermal cells and in the seed coat, respectively (Verweij et al. 2016, Gonzalez et al. 2016). In this study we functional characterized VvWRKY26 identified as the closest grapevine homolog of PhPH3 and AtTTG2 (Wang et al. 2014; Verweij et al. 2016). VvWRKY26 can fulfil the PH3 function in the regulation of vacuolar pH and impact many aspects of transport when constitutively expressed in petunia ph3 mutant. By a global correlation analysis of gene expression and by transient over-expression in Vitis vinifera cv. Sultana, we showed transcriptomic relationships of VvWRKY26 with many genes related to acidification and trafficking in grapevine. Moreover, our results indicate an involvement in flavonoid pathway mainly in the control in PA biosynthesis in grapevine that is supported by its expression profile. Overall, with the identification of VvWRKY26 our studies might pave the way towards the comprehension of regulatory mechanism underlying the acidification that contributes to the final berry quality traits.
2017-03-08 | GSE86891 | GEO
Project description:The WRKY family represents a plant-specific class of zinc-finger transcription factors (TF) well known for regulating abiotic and biotic stress tolerance and also for their emergent role in the control of various developmental and physiological processes (Rushton et al. 2010, Schluttenhofer et al. 2015). The well-characterized AtTTG2, PhPH3 and BnTTG2 are ortholog WRKY proteins with interchangeable functions ascribed to an emergent clade whose regulatory functions are mainly associated with vacuolar metabolism (Li et al. 2015, Verweij et al. 2016, Gonzalez et al. 2016). In particular, PH3 of Petunia hybrida and TTG2 of Arabidopsis thaliana both act in the control of vacuolar pH and trafficking influencing the deposition of secondary metabolites in the petal epidermal cells and in the seed coat, respectively (Verweij et al. 2016, Gonzalez et al. 2016). In this study we functional characterized VvWRKY26 identified as the closest grapevine homolog of PhPH3 and AtTTG2 (Wang et al. 2014; Verweij et al. 2016). VvWRKY26 can fulfil the PH3 function in the regulation of vacuolar pH and impact many aspects of transport when constitutively expressed in petunia ph3 mutant. By a global correlation analysis of gene expression and by transient over-expression in Vitis vinifera cv. Sultana, we showed transcriptomic relationships of VvWRKY26 with many genes related to acidification and trafficking in grapevine. Moreover, our results indicate an involvement in flavonoid pathway mainly in the control in PA biosynthesis in grapevine that is supported by its expression profile. Overall, with the identification of VvWRKY26 our studies might pave the way towards the comprehension of regulatory mechanism underlying the acidification that contributes to the final berry quality traits.
2017-03-08 | GSE86890 | GEO
Project description:A small set of TTG2-like homolog proteins from different species belonging to the WRKY family of transcription factors were shown to share a similar mechanism of action and to control partially conserved biochemical/developmental processes in their native species. In particular, by activating P-ATPases residing on the tonoplast, PH3 from Petunia hybrida promotes vacuolar acidification in petal epidermal cells whereas TTG2 from Arabidopsis thaliana enables the accumulation of proanthocyanidins in the seed coat. In this work we functionally characterized VvWRKY26 identified as the closest grapevine homolog of PhPH3 and AtTTG2. When constitutively expressed in petunia ph3 mutant, VvWRKY26 can fulfill the PH3 function in the regulation of vacuolar pH and restores the wild type pigmentation phenotype. By a global correlation analysis of gene expression and by transient over-expression in Vitis vinifera, we showed transcriptomic relationships of VvWRKY26 with many genes related to vacuolar acidification and transport in grapevine. Moreover, our results indicate an involvement in flavonoid pathway possibly restricted to the control of proanthocyanidin biosynthesis that is consistent with its expression pattern in grape berry tissues. Overall, the results show that, in addition to regulative mechanisms and biological roles shared with TTG2-like orthologs, VvWRKY26 can play roles in fleshy fruit development that have not been previously reported in studies from dry fruit species. This study paves the way toward the comprehension of the regulatory network controlling vacuolar acidification and flavonoid accumulation mechanisms that contribute to the final berry quality traits in grapevine.
| S-EPMC5214514 | biostudies-literature
Project description:Functional characterization of a WRKY transcription factor involved in the regulation of vacuolar transport and flavonoid biosynthesis
| PRJNA342832 | ENA
Project description:WRKYs play important roles in plant metabolism, but their regulation mechanism in Rehmannia glutinosa remains elusive. In this study, 37 putative WRKY transcription factors (TFs) with complete WRKY domain from R. glutinosa transcriptome sequence data were identified. Based on their conserved domains and zinc finger motif, the R. glutinosa WRKY TFs were divided into five groups. Structural feature analysis shows that the 37 RgWRKY proteins contain WRKYGQK/GKK domains and a C2H2/C2HC-type zinc finger structure. To identify the function of RgWRKY members involved in acteoside biosynthesis, transcriptional profiles of 37 RgWRKYs in hairy roots under salicylic acid (SA), methyl jasmonate (MeJA), and hydrogen peroxide (H2O2) treatments were systematically established using RNA-seq analysis. Based on the correlationship between the expression levels of RgWRKY genes and acteoside content, RgWRKY7, RgWRKY23, RgWRKY34, RgWRKY35, and RgWRKY37 were suggested to be involved in acteoside biosynthesis in R. glutinosa, and RgWRKY37 was selected for gene functional research. Overexpression of RgWRKY37 increased the content of acteoside and total phenylethanoid glycosides (PhGs) in hairy roots and enhanced the transcript abundance of seven enzyme genes involved in the acteoside biosynthesis pathway. These results strongly suggest the involvement of the WRKY transcription factor in the regulation of acteoside biosynthesis.
| S-EPMC8511629 | biostudies-literature
Project description:In grapevine, flavonoids constitute one of the most abundant subgroups of secondary metabolites, influencing the quality, health value, and typicity of wines. Their synthesis in many plant species is mainly regulated at the transcriptional level by modulation of flavonoid pathway genes either by single regulators or by complexes of different regulators. In particular, bZIP and MYB factors interact synergistically in the recognition of light response units present in the promoter of some genes of the pathway, thus mediating light-dependent flavonoid biosynthesis. We recently identified VvibZIPC22, a member of clade C of the grapevine bZIP family, in a quantitative trait locus (QTL) specifically associated with kaemperol content in mature berries. Here, to validate the involvement of this candidate gene in the fine regulation of flavonol biosynthesis, we characterized its function by in vitro and in vivo experiments. A role for this gene in the control of flavonol biosynthesis was indeed confirmed by its highest expression at flowering and during UV light-mediated induction, paralleled by accumulation of the flavonol synthase 1 transcript and flavonol compounds. The overexpression of VvibZIPC22 in tobacco caused a significant increase in several flavonoids in the flower, via induction of general and specific genes of the pathway. In agreement with this evidence, VvibZIPC22 was able to activate the promoters of specific genes of the flavonoid pathway, alone or together with other factors, as revealed by transient reporter assays. These findings, supported by in silico indications, allowed us to propose VvibZIPC22 as a new regulator of flavonoid biosynthesis in grapevine.
| S-EPMC4892739 | biostudies-literature
Project description:BACKGROUND:The basic helix-loop-helix (bHLH) transcription factors (TFs), as one of the largest families of TFs, play important roles in the regulation of many secondary metabolites including flavonoids. Their involvement in flavonoids synthesis is well established in vascular plants, but not as yet in the bryophytes. In liverworts, both bisbibenzyls and flavonoids are derived through the phenylpropanoids pathway and share several upstream enzymes. RESULTS:In this study, we cloned and characterized the function of PabHLH1, a bHLH family protein encoded by the liverworts species Plagiochasma appendiculatum. PabHLH1 is phylogenetically related to the IIIf subfamily bHLHs involved in flavonoids biosynthesis. A transient expression experiment showed that PabHLH1 is deposited in the nucleus and cytoplasm, while the yeast one hybrid assay showed that it has transactivational activity. When PabHLH1 was overexpressed in P. appendiculatum thallus, a positive correlation was established between the content of bibenzyls and flavonoids and the transcriptional abundance of corresponding genes involved in the biosynthesis pathway of these compounds. The heterologous expression of PabHLH1 in Arabidopsis thaliana resulted in the activation of flavonoids and anthocyanins synthesis, involving the up-regulation of structural genes acting both early and late in the flavonoids synthesis pathway. The transcription level of PabHLH1 in P. appendiculatum thallus responded positively to stress induced by either exposure to UV radiation or treatment with salicylic acid. CONCLUSION:PabHLH1 was involved in the regulation of the biosynthesis of flavonoids as well as bibenzyls in liverworts and stimulated the accumulation of the flavonols and anthocyanins in Arabidopsis.
| S-EPMC6854758 | biostudies-literature
Project description:Cranberries (Vaccinium macrocarpon Ait.), renowned for their excellent health benefits, are an important berry crop. Here, we performed transcriptome sequencing of one cranberry cultivar, from fruits at two different developmental stages, on the Illumina HiSeq 2000 platform. Our main goals were to identify putative genes for major metabolic pathways of bioactive compounds and compare the expression patterns between white fruit (W) and red fruit (R) in cranberry.In this study, two cDNA libraries of W and R were constructed. Approximately 119 million raw sequencing reads were generated and assembled de novo, yielding 57,331 high quality unigenes with an average length of 739 bp. Using BLASTx, 38,460 unigenes were identified as putative homologs of annotated sequences in public protein databases, including NCBI NR, NT, Swiss-Prot, KEGG, COG and GO. Of these, 21,898 unigenes mapped to 128 KEGG pathways, with the metabolic pathways, secondary metabolites, glycerophospholipid metabolism, ether lipid metabolism, starch and sucrose metabolism, purine metabolism, and pyrimidine metabolism being well represented. Among them, many candidate genes were involved in flavonoid biosynthesis, transport and regulation. Furthermore, digital gene expression (DEG) analysis identified 3,257 unigenes that were differentially expressed between the two fruit developmental stages. In addition, 14,473 simple sequence repeats (SSRs) were detected.Our results present comprehensive gene expression information about the cranberry fruit transcriptome that could facilitate our understanding of the molecular mechanisms of fruit development in cranberries. Although it will be necessary to validate the functions carried out by these genes, these results could be used to improve the quality of breeding programs for the cranberry and related species.
| S-EPMC4556307 | biostudies-literature
Project description:Because of the importance of wood in many industrial applications, tremendous studies have been performed on wood formation, especially in lignin biosynthesis. MYB transcription factors (TFs), which consist of a large family of plant TFs, have been reported to directly regulate lignin biosynthetic genes in a number of plants. In this study, we describe the cloning and functional characterization of PtoMYB216, a cDNA isolated from Chinese white poplar (Populus tomentosa Carr.). PtoMYB216 encodes a protein belonging to the R2R3-MYB family and displays significant similarity with other MYB factors shown to regulate lignin synthesis in Arabidopsis. Gene expression profiling studies showed that PtoMYB216 mRNA is specifically expressed during secondary wall formation in wood. The 1.8-kb promoter sequence of PtoMYB216 was fused to the GUS coding sequence and introduced into wild-type A. thaliana. GUS expression was shown to be restricted to tissues undergoing secondary cell wall formation. Overexpression of PtoMYB216 specifically activated the expression of the upstream genes in the lignin biosynthetic pathway and resulted in ectopic deposition of lignin in cells that are normally unligninified. These results suggest that PtoMYB216 is specific transcriptional activators of lignin biosynthesis and involved in the regulation of wood formation in poplar.
| S-EPMC3810269 | biostudies-literature
Project description:BackgroundIncreased defense against a variety of pathogens in plants is achieved through activation of a mechanism known as systemic acquired resistance (SAR). The broad-spectrum resistance brought about by SAR is mediated through salicylic acid (SA). An important step in SA biosynthesis in Arabidopsis is the conversion of chorismate to isochorismate through the action of isochorismate synthase, encoded by the ICS1 gene. Also AVRPPHB SUSCEPTIBLE 3 (PBS3) plays an important role in SA metabolism, as pbs3 mutants accumulate drastically reduced levels of SA-glucoside, a putative storage form of SA. Bioinformatics analysis previously performed by us identified WRKY28 and WRKY46 as possible regulators of ICS1 and PBS3.ResultsExpression studies with ICS1 promoter::?-glucuronidase (GUS) genes in Arabidopsis thaliana protoplasts cotransfected with 35S::WRKY28 showed that over expression of WRKY28 resulted in a strong increase in GUS expression. Moreover, qRT-PCR analyses indicated that the endogenous ICS1 and PBS3 genes were highly expressed in protoplasts overexpressing WRKY28 or WRKY46, respectively. Electrophoretic mobility shift assays indentified potential WRKY28 binding sites in the ICS1 promoter, positioned -445 and -460 base pairs upstream of the transcription start site. Mutation of these sites in protoplast transactivation assays showed that these binding sites are functionally important for activation of the ICS1 promoter. Chromatin immunoprecipitation assays with haemagglutinin-epitope-tagged WRKY28 showed that the region of the ICS1 promoter containing the binding sites at -445 and -460 was highly enriched in the immunoprecipitated DNA.ConclusionsThe results obtained here confirm results from our multiple microarray co-expression analyses indicating that WRKY28 and WRKY46 are transcriptional activators of ICS1 and PBS3, respectively, and support this in silico screening as a powerful tool for identifying new components of stress signaling pathways.
| S-EPMC3120740 | biostudies-literature