Project description:Background: Papaya (Carica papaya L.) is a commercially important crop that produces climacteric fruits with a soft and sweet pulp that contain a wide range of health promoting phytochemicals. Despite its importance, little is known about transcriptional modifications during fruit ripening and its control. In this study we report the analysis of ripe papaya transcriptome by using a cross-species (XSpecies) microarray technique based on the phylogenetic proximity between papaya and Arabidopsis thaliana. Results: Papaya transcriptome analyses resulted in the identification of 414 ripening-related genes and some of them had their expression validated by qPCR. The transcription profile was then compared with that from ripening tomato and grape. Overall, the transcriptomics analysis revealed many similarities between ripening in papaya and tomato especially with respect to primary metabolism, regulation of transcription, biotic and abiotic stress and cell wall metabolism. XSpecies microarray data indicate that transcription factors (TFs) of the MADS-box, NAC and AP2/ERF gene families are involved in the control of papaya ripening and reveal that cell wall-related gene expression in papaya showed similarities to the expression profiles seen in A. thaliana during hypocotyl development. Conclusion: The cross-species array experiment was successful in identifying ripening-related genes in papaya. The data indicated common and diverse elements of transcription control between fruit bearing taxa and has also indicated a possible distinct co-evolutionary mechanism for papaya cell wall disassembling system. The present study represents new topics for future researches that would help complement the structural genomic data provided by the papaya genome, since there is no gene-chip available for this plant organism. Papaya ripe transcriptome was analysed using mRNA extracted from unripe and ripe fruit from 2 replicates. After microarray hybridization in ATH1-121501 chip, data were normalized against data generated by papaya DNA hybridization in another ATH1-121501 chip and analysed using perl algorithms (masks).
Project description:Background: Papaya (Carica papaya L.) is a commercially important crop that produces climacteric fruits with a soft and sweet pulp that contain a wide range of health promoting phytochemicals. Despite its importance, little is known about transcriptional modifications during fruit ripening and its control. In this study we report the analysis of ripe papaya transcriptome by using a cross-species (XSpecies) microarray technique based on the phylogenetic proximity between papaya and Arabidopsis thaliana. Results: Papaya transcriptome analyses resulted in the identification of 414 ripening-related genes and some of them had their expression validated by qPCR. The transcription profile was then compared with that from ripening tomato and grape. Overall, the transcriptomics analysis revealed many similarities between ripening in papaya and tomato especially with respect to primary metabolism, regulation of transcription, biotic and abiotic stress and cell wall metabolism. XSpecies microarray data indicate that transcription factors (TFs) of the MADS-box, NAC and AP2/ERF gene families are involved in the control of papaya ripening and reveal that cell wall-related gene expression in papaya showed similarities to the expression profiles seen in A. thaliana during hypocotyl development. Conclusion: The cross-species array experiment was successful in identifying ripening-related genes in papaya. The data indicated common and diverse elements of transcription control between fruit bearing taxa and has also indicated a possible distinct co-evolutionary mechanism for papaya cell wall disassembling system. The present study represents new topics for future researches that would help complement the structural genomic data provided by the papaya genome, since there is no gene-chip available for this plant organism.
Project description:To uncover a suit of genes related to the consumer preferred flavours, whole RNA sequencing followed by de novo genome assembly was performed on extreme flavoured papaya varieties RB1 (preferred with sweet flavour and floral aroma) and 1B (non-preferred with bitter flavour and musty aroma) fruits at ripe and unripe stages. We then performed gene expression profiling analysis using data obtained from RNA-seq of 2 different papaya varieties at ripe and unripe stages.
Project description:For identifying genes for sex determination in papaya, digital gene expression analysis by Ht-SuperSAGE (Matsumura et al., 2010) was carried out in flowers from male, female and hermaphrodite plants of papaya. Total more than 9,273,744 26bp-tags were obtained by sequence analysis using SOLiD3 and mapped on papaya primitive sex chromosome sequences.
Project description:For identifying genes for sex determination in papaya, digital gene expression analysis by Ht-SuperSAGE (Matsumura et al., 2010) was carried out in flowers from male, female and hermaphrodite plants of papaya. Total more than 9,273,744 26bp-tags were obtained by sequence analysis using SOLiD3 and mapped on papaya primitive sex chromosome sequences. 6 samples examined: male young flowerbud, male mature flower bud, female young flower bud, female mature flower bud, hermaphrodite young flower bud, hermaphrodite mature flower bud
Project description:Papaya (Carica papaya L.) is a typical climacteric fruit, undergoing massive physico-chemical changes during ripening. Although papaya is widely cultivated and consumed, few studies have characterized the variations in metabolism during its ripening process at the proteasome level. Using an integrated approach involving Tandem Mass Tag labeling and liquid chromatography–mass spectrometry analysis, proteomes of papaya fruit at different ripening stages were investigated. A total of 3220 proteins were identified, of which 2818 were quantified. The differential accumulated proteins (DAPs) exhibited various biological functions and diverse subcellular localizations. Among the DEPs, most of the pathogen defense-related proteins were down-regulated, suggesting that disease resistance decreased during the ripening process. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that various metabolic pathways were significantly altered, particularly in flavonoid and fatty acid metabolisms. The up-regulation of several flavonoid biosynthesis-related proteins may provide more raw materials for pigment biosynthesis, accelerating the color variation of papaya fruit. Thus, variations in the fatty acid metabolism-related enzymes were investigated. For example, a lipoxygenase, which catalyzes the conversion of ACC to ethylene, was significantly induced, suggesting a cross-talk between the lipoxygenase-mediated fatty acid metabolism and the hormone-controlled fruit ripening in papaya. Furthermore, the contents of several important fatty acids were determined, and increased unsaturated fatty acids may be associated with papaya fruit volatile formation. Our data may give an intrinsic explanation of the variations in metabolism during the ripening process of papaya fruit and serve as a comprehensive resource for investigating the regulation mechanism involved.
Project description:The aim of this research was to study the effects of cis-element differences between the X, Y and Yh alleles on the expression of CpMDAR4, a potential candidate gene for sex differentiation in papaya, using a transcriptional reporter system in a model species Arabidopsis thaliana. Possible effects of a retrotransposon insertion in the Y and Yh alleles on the transcription and expression of CpMDAR4 alleles in papaya flowers were also examined. When comparing promoters and cis-regulatory elements among genes in the non-recombining region of the sex chromosomes, paired genes exhibited differences. Our results showed that differences in the promoter sequences of the CpMDAR4 alleles drove the expression of a reporter gene to different flower tissues in Arabidopsis. β-glucuronidase staining analysis of T2 and T3 lines for constructs containing 5’ deletions of native Y and Yh allele promoters showed the loss of specific expression of the reporter gene in the anthers, confirming the existence and location of cis-regulatory element POLLEN1LELAT52. The expression analysis of CpMDAR4 alleles in papaya flowers also showed that all alleles are actively expressed in different flower tissues, with the existence of a shorter truncated isoform, with unknown function, for the Y and Yh alleles due to an LTR-RT insertion in the Y and Yh chromosomes. The observed expression patterns in Arabidopsis thaliana flowers and the expression patterns of CpMDAR4 alleles in papaya flowers, suggest that MDAR4 might have a role on development of reproductive organs in papaya, and that it constitutes an important candidate for sex differentiation.