Project description:Insights into flavor formation during fruit ripening can guide the development of breeding strategies that balance consumer and producer needs. Cherry tomatoes possess a distinctive taste, yet research on quality formation is limited. Here, metabolomic and transcriptomic analyses were conducted on different ripening stages. The results revealed differentially accumulated metabolites during fruit ripening, providing candidate metabolites related to flavor. Interestingly, several key flavor-related metabolites already reached a steady level at the mature green stage. Transcriptomic analysis revealed that the expression levels of the majority of genes tended to stabilize after the pink stage. Enrichment analysis demonstrated that changes in metabolic and biosynthetic pathways were evident throughout the entire process of fruit ripening. Compared to disease resistance and fruit color genes, genes related to flavor and firmness may have a broader impact on the accumulation of metabolites. Furthermore, we discovered the interconversion patterns between glutamic acid and glutamine, as well as the biosynthesis patterns of flavonoids. These findings contribute to our understanding of fruit quality formation mechanisms and support breeding programs aimed at improving fruit quality traits.
Project description:Tomato, which can be eaten as a vegetable or fruit, is one of the most popular and nutritionally important crops around the world. Although most plants of the cherry tomato cultivar 'Minichal' have a normal phenotype, some plants have a stunted phenotype with reduced plant height, leaf size, and fruit size, as well as altered leaf and fruit shape. To investigate the molecular mechanisms underlying these differences, we generated RNA-seq libraries from pooled leaf samples of 10 normal (N) and 10 stunted (S) plants. Using the Illumina sequencing platform, we obtained a total of 115.45 million high-quality clean reads assembled into 35,216 genes and 35,216 transcripts. A total of 661 genes were differentially expressed between N and S plants. Of these, 420 differentially expressed genes (DEGs) were up-regulated, and 221 DEGs were down-regulated. The RNA-seq data were validated using quantitative reverse-transcription PCR. Enrichment analysis of DEGs using the Kyoto Encyclopedia of Genes and Genomes (KEGG) showed that the enriched pathways were involved in steroid biosynthesis, homologous recombination, and mismatch repair. Among these, three genes related to steroid biosynthesis, including 3BETAHSD/D2, DIM and DWF5 were down-regulated in S compared to N. Of these, DIM and DWF5 are known to be involved in brassinosteroid biosynthesis. Our results thus provide a useful insight into dwarfism in cherry tomato, and offer a platform for evaluating related species.
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.
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:The study of climacteric fruit ripening in tomato has been facilitated by the spontaneous ripening mutants Colorless non-ripening (Cnr), non-ripening (nor), and ripening inhibitor (rin). These mutants effect the genes encoding ripening transcription factors (TFs) SPL-CNR, NAC-NOR, and MADS-RIN causing pleiotropic defects to the ripening program. Here, we demonstrate that some ripening processes occur in the mutant fruit but at later stages of development compared to the wild type. The rin and nor mutant fruit exhibit similar quality traits to wildtype at later stages of ripening and senescence and delayed expression of ripening-associated genes. In addition, we propose that the Cnr mutant has a broader range of effects to fruit development than just fruit ripening. Cnr fruit show distinct differences from wild type in ripening phenotypic traits and gene expression profiles prior to the initiation of ripening. We provide new evidence that some mutants can produce more ethylene than basal levels and demonstrate ABA accumulation is also affected by the mutations. Studies have examined the relationship between the CNR, RIN, and NOR TFs based on protein-protein interactions and transcriptional regulation during fruit ripening. We describe the genetic interactions affecting specific fruit traits by using homozygous double mutants. Cnr predominantly influences the phenotype of the Cnr/nor and Cnr/rin double mutants but additional defects beyond either single mutation is evident in the transcriptome of the Cnr/nor double mutant. Our reevaluation of the Cnr, nor, and rin mutants provides new insights the utilization of the mutants in breeding and studying fruit development.
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: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.