ABSTRACT: Functional characterization of a WRKY transcription factor involved in the regulation of vacuolar transport and flavonoid biosynthesis in petunia
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.
Project description:Functional characterization of a WRKY transcription factor involved in the regulation of vacuolar transport and flavonoid biosynthesis
Project description:Functional characterization of a WRKY transcription factor involved in the regulation of vacuolar transport and flavonoid biosynthesis in grapevine
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.
Project description:To better understand how diurnal transcriptional regulation contributes to day/night cycles of volatile emission from the petunia flower, RNA extracted from corolla in the morning (7AM) and evening (7PM) was sequenced to determine genes differentially expressed at the two time points.
Project description:To better understand how diurnal transcriptional regulation contributes to day/night cycles of volatile emission from the petunia flower, cross-linked chromatin from corolla in the morning (7AM) and evening (7PM) was immunoprecipitated with antibodies against 4 histone marks associated with trancriptional activity to determine islands enriched for the marks in morning and evening.
Project description:One of the primary objectives of plant biotechnology is to increase resistance to abiotic stresses, such as salinity. Salinity is a major abiotic stress and increasing crop resistant to salt continues to the present day as a major challenge. Salt stress disturbs cellular environment leading to protein misfolding, affecting normal plant growth and causing agricultural losses worldwide. The advent of state-of-the-art technologies such as high throughput mRNA sequencing (RNA-Seq) has revolutionized whole-transcriptome analysis by allowing, with high precision, to measure changes in gene expression. In this work, we used tissue-specific RNA-Seq to gain insight into the Petunia hybrida transcriptional responses under sodium chloride (NaCl) stress using a controlled hydroponic system. Roots and leaves samples were taken from a continuum of 48 hours of acute 150 mM NaCl. This analysis revealed a set of tissue- and- time point specific differentially expressed genes, such as genes related to transport, signal transduction, ion homeostasis as well as novel and undescribed genes, such as Peaxi162Scf00003g04130 and Peaxi162Scf00589g00323 expressed only in roots under salt stress. In this work, we identified early and late expressed genes in response to salt stress while providing a core of differentially express genes across all time points and tissues, including the trehalose-6-phosphate synthase 1 (TPS1), a glycosyltransferase reported in salt tolerance in other species. To test the function of the novel petunia TPS1 allele, we cloned and showed that TPS1 is a functional plant gene capable of complementing the trehalose biosynthesis pathway in mutants (tps1) yeast. The list of candidate genes to enhance salt tolerance provided in this work constitutes a major effort to better understand the detrimental effects of salinity in petunia with direct implications for other economically important Solanaceous species
Project description:Petunia floral scent production and emission is highly regulated, with a major role for the transcription factor ODORANT1 (ODO1) in directing activation of volatile biosynthesis. Using ChIP-seq of tagged ODO1 protein from petunia flowers, and RNA-seq of wild-type and odo1i RNAi flowers, the ODORANT1-regulated gene network of petunia is described, which extends to branches involved in phenylpropanoid intermediate production and S-adenosyl-methionine biosynthesis to potentiate production and emission of volatiles. Analysis of direct targets of regulation has also enabled the identification of an ODO1 binding motif.