Project description:Gene expression in three stages of ripening tomato fruit (variety Ailsa Craig) was determined with the EUTOM3 Affymetrix array in order to compare with degradrome sequencing data from study GSE42661, treated as RNAseq.
Project description:Here, we found that the tomato jmjC domain-containing gene SlJMJ6 encodes a histone lysine demethylase that specifically demethylates H3K27 methylation. Overexpression of SlJMJ6 accelerated fruit ripening in tomato, which is associated with the up-regulated expression of a large number of ripening-related genes. Integrated analysis of RNA-seq and ChIP-seq data identified 55 genes that are targeted directly by SlJMJ6 and transcriptionally up-regulated with decreased H3K27m3 in SlJMJ6 overexpressing (SlJMJ6-OE) fruits. A large number of the SlJMJ6-regulated genes are involved in transcription regulation, ethylene biosynthesis, cell wall degradation, pigment biosynthesis, and hormone signaling. Fourteen ripening-related genes including RIN, ACS4, ACO1, PL, TBG4 were confirmed to be directly regulated by SlJMJ6 through removing H3K27me3. Taken together, these results indicated that SlJMJ6 is a ripening prompting H3K27me3 demethylase that activates the expression of the ripening-related genes by modulating H3K27me3, thereby facilitating fruit ripening in tomato. To our knowledge, this is the first report of the involvement of a histone lysine demethylase in the regulation of fruit ripening.
Project description:Here, we found that the tomato jmjC domain-containing gene SlJMJ6 encodes a histone lysine demethylase that specifically demethylates H3K27 methylation. Overexpression of SlJMJ6 accelerated fruit ripening in tomato, which is associated with the up-regulated expression of a large number of ripening-related genes. Integrated analysis of RNA-seq and ChIP-seq data identified 55 genes that are targeted directly by SlJMJ6 and transcriptionally up-regulated with decreased H3K27m3 in SlJMJ6 overexpressing (SlJMJ6-OE) fruits. A large number of the SlJMJ6-regulated genes are involved in transcription regulation, ethylene biosynthesis, cell wall degradation, pigment biosynthesis, and hormone signaling. Fourteen ripening-related genes including RIN, ACS4, ACO1, PL, TBG4 were confirmed to be directly regulated by SlJMJ6 through removing H3K27me3. Taken together, these results indicated that SlJMJ6 is a ripening prompting H3K27me3 demethylase that activates the expression of the ripening-related genes by modulating H3K27me3, thereby facilitating fruit ripening in tomato. To our knowledge, this is the first report of the involvement of a histone lysine demethylase in the regulation of fruit ripening.
Project description:For exploring whether mRNA m6A modification participates in the regulation of tomato fruit ripening, we performed m6A-seq in three tomato fruit samples, including wild-type (WT) at 39 days post-anthesis (DPA) and 42 DPA, and Cnr mutant at 42 DPA, with three biological replicates. mRNA methylome analysis reveals that m6A methylation is a prevalent modification in mRNA of tomato fruit and the m6A sites are predominantly enriched in the stop codon and 3’ untranslated region, where m6A deposition has been proved to negatively correlate with gene expression. Hundreds of ripening-induced and ripening-repressed genes, including the SlDML2, were found to harbour changed m6A levels during fruit ripening or in the Cnr mutant, implicating the involvement of m6A modification in the regulation of fruit ripening.
Project description:The aim of this study is to generate gene regulatory networks by analyzing Affymetrix GeneChip expression datasets from four different stages of tomato fruit ripening, Breaker (Br), Turning (Tu), Pink (Pk) and Red Ripe (RR) with the LeMoNe algorithm in order to identify co expression modules and their putative regulatory TFs.
Project description:Transcription factors (TFs) are important regulators of plant growth and development and responses to stresses. TFs themselves are also susceptible to multiple post-translational modifications (PTMs). Relatively, redox-mediated PTM of TFs in plants is not well elucidated. Here, we found that NON-RIPENING (NOR), a master TF regulating tomato fruit ripening, is a target of SlMsrE4 or SlMsrB2, the methionine sulfoxide reductase A and B in tomato, respectively. Methionine oxidation in NOR, i.e. sulfoxidation, or mimicking sulfoxidation by mutating Met138 to glutamine, leads to the decreased DNA-binding capacity and transcriptional regulatory activity in vitro. On the other hand, SlMsrE4 and SlMsrB2 can partially repair oxidized-NOR and restore its DNA-binding capacity. Genetic transformation of the nor mutant with NOR genomic DNA almost completely rescues the ripening phenotype. However, transformation of nor with NOR-M138Q, the mimicked methionine sulfoxidation, inhibits the restore of fruit ripening phenotype, and this is associated with the decreased DNA-binding and transcriptional activation of numerous ripening-related genes. Taken together, these findings uncover a novel mechanism by which Msr-mediated redox modification of NOR regulates the expression of ripening-related genes, thereby influencing tomato fruit ripening. To our knowledge, this is the first report that redox modification of TF regulates fruit ripening. nor is a NOR mutant, the phenotype is obstructed by maturity; NOR-12 is a rotational NOR in NOR mutant, the phenotype is a mature inhibition phenotype that basically restores nor mutant; Nor-18 is a rotation of NOR-M138Q in nor mutant, phenotype with the effect of restoring maturity, but the recovery efficiency is lower than the swing NOR.
Project description:DNA methylation is a conserved epigenetic mark important for genome integrity, development and environmental responses in plants and mammals. Active DNA demethylation in plants is initiated by a family of 5mC DNA glycosylases/lyases (i.e. DNA demethylases). The role of DNA demethylases in transposon regulation, pathogen responses, and gene imprinting and other developmental processes have been studied extensively in the model plant Arabidopsis thaliana. Recent studies suggested a role of active DNA demethylation in fruit ripening in tomato. In this study, we generated loss-of-function mutant alleles of a tomato gene, SlROS1/SlDML1/2, which is a close homolog of the Arabidopsis DNA demethylase gene ROS1. In the fruits of the tomato mutants, increased DNA methylation was found in thousands of genes. These genes include not only hundreds of ripening induced genes but also many ripening repressed genes. Our results show that SlROS1 is critical for tomato fruit ripening, and suggest that active DNA demethylation is required for both the activation of ripening induced genes and inhibition of ripening repressed genes.
Project description:Postharvest fungal pathogens benefit from the increased host susceptibility that occurs during fruit ripening. In unripe fruit, pathogens often remain quiescent and unable to cause disease until ripening begins, emerging at this point into destructive necrotrophic lifestyles that quickly result in fruit decay. Here, we demonstrate that one such pathogen, Botrytis cinerea, actively induces ripening processes in order to facilitate infections and promote disease. Assessments of ripening progression revealed that B. cinerea accelerated external coloration, ethylene production, and softening in unripe fruit, while mRNA sequencing of inoculated unripe fruit confirmed the corresponding upregulation of host genes involved in ripening processes, such as ethylene biosynthesis and cell wall degradation. Furthermore, ELISA-based glycomics profiling of fruit cell wall polysaccharides revealed remarkable similarities in the cell wall polysaccharide changes caused by both infections of unripe fruit and ripening of healthy fruit, particularly in the increased accessibility of pectin polysaccharides. Virulence and additional ripening assessment experiments with B. cinerea knockout mutants showed that induction of ripening is dependent on the ability to infect the host and break down pectin. The B. cinerea double knockout Δbcpg1Δbcpg2 lacking two critical pectin degrading enzymes was found to be incapable of emerging from quiescence even long after the fruit had ripened at its own pace, suggesting that the failure to accelerate ripening severely inhibits fungal survival on unripe fruit. These findings demonstrate that active induction of ripening in unripe tomato fruit is an important infection strategy for B. cinerea.
Project description:Gene expression in three stages of ripening tomato fruit (variety Ailsa Craig) was determined with the EUTOM3 Affymetrix array in order to compare with degradrome sequencing data from study GSE42661, treated as RNAseq. three replicates of each stage (MG, mature green; T, turning/breaker; RR, red ripe) were hybridized; Expression values were normalized for each sample and reported by iTAG2.3 cDNA identifier in the accompanying matrix table.
Project description:Tomato fruit ripening is associated with a dramatic increase in susceptibility to the fungal pathogen Botrytis cinerea, the causal agent of gray mold. Mature green fruit, prior to ripening, are largely resistant to B. cinerea, whereas red fruit, at the end of ripening, are susceptible to B. cinerea infection. We used microarrays to detail the gene expression changes that are induced by B. cinerea when tomato fruit at unripe and ripe stages are infected. Keywords: plant responses to pathogens