Project description:The environment has a profound influence on the tomato fruit organoleptic quality. The extent of which depends from a well-regulated and dynamic interplay among genes, metabolites and sensorial attributes. A systems biology approach, could be useful for elucidating complex interacting mechanisms regulating the plasticity of sensorial quality properties. In order to investigate the transcriptomic and metabolomic environmentally challenged remodeling and to evaluate organoleptic consequences of such variation, three tomato (Solanumlycopersisum) genotypes, Heinz 1706, San Marzano and Vesuviano were grown in two different localities. The metabolome and transcriptome analysis revealed common as well as genotype specific challenged pathways, the dynamic of which are in turn regulated by genome organization and gene diversity. When combined with sensorial data, through a network analysis, interesting aspects of fruit quality fine regulation were revealed: first, duplicated genes and different genes/isoforms and transcription factors have a dominant role in shaping environment response; second the lost or gained interactions and/or the changing position of a node is crucial for phenotypic expression of a given trait; third, sensorial traits as sweetness, turgidity and are much responsive to environment. The fundamental role of cell wall metabolism in tuning all the quality attributes was also highlighted. Tomato genotypes, although activate the same fruit related quality processes, follow different transcriptomic, metabolomic and sensorial trajectories depending of their own genetic makeup.
Project description:To evaluate the role of seeds in fruit quality, we induced parthenocarpy in tomato by regulating ovule-specific auxin synthesis or responsiveness using the INO promoter from A. thaliana, which is expressed in the outer layer of the integuments during early stages of ovule development. We compared these to fruit where the same coding regions were expressed from the DeFH9 promoter which is expressed in carpel tissues during early stages of ovule development. Expression of auxin synthesis or responsiveness genes by both of these promoters produced seedless parthenocarpic tomato fruit. We compared fruit samples using the Affymetrix tomato GeneChip (GPL4741) to determine how gene regulation and expression differed between wild-type and transgenic fruit. Keywords: genetic modification
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:To evaluate the role of seeds in fruit quality, we induced parthenocarpy in tomato by regulating ovule-specific auxin synthesis or responsiveness using the INO promoter from A. thaliana, which is expressed in the outer layer of the integuments during early stages of ovule development. We compared these to fruit where the same coding regions were expressed from the DeFH9 promoter which is expressed in carpel tissues during early stages of ovule development. Expression of auxin synthesis or responsiveness genes by both of these promoters produced seedless parthenocarpic tomato fruit. We compared fruit samples using the Affymetrix tomato GeneChip (GPL4741) to determine how gene regulation and expression differed between wild-type and transgenic fruit. Experiment Overall Design: Wild-type fruit with seeds was compared with transgenic lines INO-IaaM, DefH9-IaaM, INO-RolB, and DefH9-RolB. To find genes with seed-specific expression, we also compared the control with wild-type fruit from which seeds had been manually removed. We had three biological replicates for each treatment and control except DefH9-RolB, for which only two replicates were available. Each CEL file from the microarray represents one plant from each line.
Project description:Cucumber (Cucumis sativus L.) is an important vegetable crop bearing fleshy pepo fruits that harvested immature. The fruit length is one of the most important agricultural traits that directly determine the fruit yield and affects fruit quality, but the regulatory mechanism of fruit length variation remains elusive. Here we found a FRUITFULL-like MADS-box gene CsFUL1 functions as a key repressor for fruit length regulation in cucumber. The expression of CsFUL1 is highly enriched in male flowers and fruits, and negatively correlated with fruit length in different cucumber lines. Notably, a key SNP in CsFUL1 was selected during cucumber domestication for long fruit. Ectopic expression of CsFUL1 was unable to rescue the indehiscent fruit phenotype of ful-1 in Arabidopsis. Overexpression of CsFUL1 resulted in increased floral organs and reduced fruit length, whereas knockdown of CsFUL1 led to elongated fruit in cucumber. Transcriptome and biochemical analyses showed that CsFUL1 regulates fruit length through two pathways: one by inhibiting the PIN-FORWED (PIN1/7)-mediated auxin transport and thus downregulates auxin related genes in the fruit, and the other by forming a tetramer with other MADS-box genes to repress the CsSUP-mediated cell division and cell expansion. In addition, we found that CsFUL1 promotes locule number variation through the classical CsWUS-CsCLV pathway. Our findings uncover the regulatory commonality and specificity during development of different fruit types, and provide an important candidate gene to customize fruit length during cucumber breeding.
Project description:Anthocyanins are high value plant antioxidants which are not present in the fruits of cultivated tomato. However, both the dominant gene Anthocyanin fruit (Aft) and the recessive gene atroviolacea (atv), introgressed into domesticated tomato from two different wild Solanum species, stimulate a limited anthocyanin pigmentation. Surprisingly, double mutant Aft/Aft atv/atv tomatoes are characterised by the presence of anthocyanins in the fruit peel, resulting in intensely purple pigmented fruit. We carried out a transcript profiling analysis using GeneChip® Tomato Genome Arrays, in order to identify differentially expressed genes when comparing wild type, Aft/Aft, atv/atv, and Aft/Aft atv/atv fruits. The expression pattern of several genes involved in the anthocyanin pathway was analyzed in detail. Among the fruit peel-associated differentially expressed transcripts, genes involved in phenylpropanoid pathway, cell wall composition, biotic and abiotic stress responses, sugar and hormone metabolism were overrepresented in Aft/Aft atv/atv. Transcriptomic analysis thus revealed that the activation of anthocyanin synthesis in tomato fruit was accompanied by a complex remodulation of gene expression, likely affecting important agronomic and merceological traits.
Project description:Purpose: The goals of this study was to provide genome-wide data to investigate the molecular mechanism of ABA regulation in many ripening related biological processes, including fruit color variation, antioxidant capacity, flavonoids biosynthesis and photosynthesis. Methods:By applying the next generation sequencing technology, we conducted a comparative analysis of exogenous ABA and NDGA effects on tomato fruit maturation. Results:The high throughput sequencing results showed that 25728 genes expressed across all three samples, and 10388 of them were identified as significantly differently expressed genes (DEGs). Exogenous ABA was found to enhance the transcription of genes in pigments metabolism, including carotenoids biosynthesis and chlorophyll degradation, whereas NDGA treatment inhibited these progresses. The results also revealed the crucial role of ABA in flavonoids synthesis and regulation of antioxidant system. Intriguingly, we also found that an inhibition of endogenous ABA significantly enhanced the transcriptional abundance of genes involved in fruit photosynthesis. Conclusions:next-generation sequencing enabled us to characterize the transcriptomes of tomato fruit treated with ABA and NDGA. By comparing these transcriptomes with control respectively, we observed that ABA could accelerate fruit maturation by positively regulating many genes related to ripening processes. Our study have turned spotlight on the pathways of fruit pigmentation, including carotenoid biosynthesis and chlorophyll metabolism. Exogenous ABA was able to up-regulate many genes in relation to the carotenoids accumulation and chlorophyll breakdown, thus promoting the color transition of tomato fruit. In addition, ABA has the potential to improve the genes related to antioxidant capacity, such as SODs, CATs, APXs, GSTs, GPXs, TrXs and PrxRs. Besides, the expression changes of genes involved in flavonoids biosynthesis after ABA exposure was striking, suggesting ABA could enhance the defense response by producing more secondary metabolite in tomato fruit. Moreover, the sequencing results also implied high level of ABA could negatively affect photosynthesis of tomato fruit, which needs more investigations to explore the interaction between ABA and photosynthesis in the future.
Project description:Industrialized tomato production faced a decrease in flavours and nutritional values due to conventional breeding and growth conditions. We addressed the question, whether commercially used tomato cultivars grown in a hydroponic system can be mycorrhizal leading to improved fruit quality. Comparing green and red fruits from non-mycorrhizal and mycorrhizal plants, differentially expressed genes (DEGs) should be found possibly being involved in processes regulating fruit maturation and nutrition.
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.