Project description:[original title] Understanding the complexity of fruit ripening by transcriptome analysis of rin mutant fruit and in silico analysis of promoters of differentially regulated genes A tomato MADS-box transcription factor, LeMADS-RIN, controls fruit ripening and mutation in this gene results in non-ripening phenotype of fruit. This mutation down-regulates certain ripening related ethylene responses, however, other ethylene responses are normal. A complete understanding of this mutation and its effect on fruit transcriptome during ripening is not clear. In this study, microarray analysis has been used to investigate the influence of rin mutation on fruit transcriptome at different stages of ripening. A total of 2,398 genes were found to be differentially expressed in wild type fruit pericarp, which on cluster analysis indicated a major shift in their expression profiles in rin mutant fruit. A total of 1,802 genes were found to be differentially expressed between wild type and rin mutant fruits and 17% of these genes encoded regulatory elements, suggesting that mutation in LeMADS-RIN results in disturbance in the regulatory transcriptional networks during ripening. Since LeMADS-RIN has been reported to bind to the CArG box of LeACS2 promoter, in-silico analysis of 51 putative promoter sequences of the genes, that showed ripening associated up-regulation in wild type but showed impairment in up-regulation in rin mutant fruit during ripening, were searched for presence of CArG box along with ethylene and auxin responsive elements. The study revealed that only 24 putative promoter sequences harbor LeMADS-RIN specific CArG box suggesting an alternative mode of regulation by LeMADS-RIN for CArG box deficient genes. Three chronological stages of tomato (Solanum lycopersicon) fruit ripening were compared between wild type and rin mutant
Project description:Post-translational modification of proteins through methylation plays important regulatory role in biological processes. Lysine methylation on histone proteins is known to play important role in chromatin structure and function. However, non-histone protein substrates of this modification remain largely unknown. Herein, we use high resolution mass spectrometry to global screening methylated substrates and lysine- methylation sites in tomato (Solanum Lycopersicum). A total of 241 sites of lysine methylation (mono-, di-, tri-methylation) in 176 proteins with diverse biological functions and subcellular localized were identified in mix tomato with different maturity. Two putative methylation motifs were detected. KEGG pathway category enrichment analysis indicated that methylated proteins are implicated in the regulation of diverse metabolic processes, including arbon fixation in photosynthetic organisms, pentose phosphate pathway, fructose and mannose metabolism, and cysteine and methionine metabolism. Three representative proteins were selected to analyze the effect of methylated modification on protein function. In addition, quantitative RT-PCR further validated the gene expression level of some key methylated proteins during fruit ripening, which are involved in oxidation reduction process, stimulus and stress, energy metabolism, signaling transduction, fruit ripening and senescence. These data represent the first report of methylation proteomic and supply abundant resources for exploring the functions of lysine methylation in tomato and other plants.
Project description:[original title] Understanding the complexity of fruit ripening by transcriptome analysis of rin mutant fruit and in silico analysis of promoters of differentially regulated genes A tomato MADS-box transcription factor, LeMADS-RIN, controls fruit ripening and mutation in this gene results in non-ripening phenotype of fruit. This mutation down-regulates certain ripening related ethylene responses, however, other ethylene responses are normal. A complete understanding of this mutation and its effect on fruit transcriptome during ripening is not clear. In this study, microarray analysis has been used to investigate the influence of rin mutation on fruit transcriptome at different stages of ripening. A total of 2,398 genes were found to be differentially expressed in wild type fruit pericarp, which on cluster analysis indicated a major shift in their expression profiles in rin mutant fruit. A total of 1,802 genes were found to be differentially expressed between wild type and rin mutant fruits and 17% of these genes encoded regulatory elements, suggesting that mutation in LeMADS-RIN results in disturbance in the regulatory transcriptional networks during ripening. Since LeMADS-RIN has been reported to bind to the CArG box of LeACS2 promoter, in-silico analysis of 51 putative promoter sequences of the genes, that showed ripening associated up-regulation in wild type but showed impairment in up-regulation in rin mutant fruit during ripening, were searched for presence of CArG box along with ethylene and auxin responsive elements. The study revealed that only 24 putative promoter sequences harbor LeMADS-RIN specific CArG box suggesting an alternative mode of regulation by LeMADS-RIN for CArG box deficient genes.
Project description:In this study, we explored the metabolome and transcriptome of the ripe fruit in nine landrace accessions representing the seven genetic groups and compared them to the mature fruit of the wild progenitor S. pimpinellifolium. The goal is to shed light in understanding the factors responsible for acquiring tomato fruit quality (taste and flavour) at molecular level during the domestication process.
Project description:In the present study, we demonstrated that application of CaCl2 to ‘Micro Tom’ tomato fruit (mature green stage) delayed fruit senescence and mature.
Project description:Tomato fruit ripening is under the control of ethylene as well as a group of ethylene-independent transcription factors, including NON-RIPENING (NOR) and RIPENING INHIBITOR (RIN). During ripening, the linear carotene lycopene accumulates at the expense of cyclic carotenoids. Fruit-specific overexpression of LYCOPENE β-CYCLASE (LCYb) under the control of the PHYTOENE DESATURASE (PDS) promoter resulted in increased levels of β-carotene and ABA and in decreased ethylene levels. Genes regulated by ABA, or involved in its synthesis and signaling, were overexpressed, while those associated with ethylene and cell wall remodeling were repressed. In agreement with the transcriptional data, LCYb-overexpressing fruits exhibited increased density of cell wall material containing linear, under-methylated pectins and displayed an array of additional ripening phenotypes, including delayed softening, increased turgor, enhanced shelf life and a thicker cuticle with a higher content of cutin monomers and triterpenoids. The levels of several primary metabolites and phenylpropanoids also changed in the transgenics, which could be attributed to delayed fruit ripening and to ABA respectively. Network correlation analysis suggests that ABA, acting through NOR and RIN, is responsible for many of the above phenotypes. These data reinforce suggestions that ABA plays an important role in tomato fruit ripening and provide clues that fruit b-carotene, acting as a precursor for ABA, actively participates in controlling the ripening process rather than merely being an output thereof. Overexpression of a LCYb gene from Arabidopsis under the control of the ripening-associated PDS promoter leads to ripe tomato fruits accumulating high β-carotene levels. Using several independent transgenic lines, we conducted a system-wide study of the effect of increased β-carotene levels on tomato fruit ripening and shelf life. Our data suggest that β-carotene, acting through ABA, is involved in a regulatory loop within the network controlling tomato fruit ripening.