Dataset Information

Combined analysis of carotenoid metabolites and the transcriptome to reveal the molecular mechanism underlying fruit colouration in zucchini (Cucurbita pepo L.).

ABSTRACT: To reveal the molecular mechanism underlying peel colouration, carotenoid metabolites and the transcriptome were jointly analysed in zucchini peels with three different colours: light green (Lg), yellow (Y), and orange (O). Our results showed that the carotenoid levels in O (157.075 μg/g) and Y (22.734 μg/g) were both significantly higher than in Lg (7.435 μg/g), while the chlorophyll content was highest in Lg (32.326 μg/g), followed by O (7.294 μg/g) and Y (4.617 μg/g). A total of 14 carotenoids were detected in zucchini peels, primarily lutein (103.167 μg/g in Lg, 509.667 μg/g in Y, and 1543.333 μg/g in O). In particular, significant accumulation of antheraxanthin, zeaxanthin, neoxanthin, and β-cryptoxanthin was first reported in orange zucchini in this study. Furthermore, two modules with hub genes related to carotenoid or chlorophyll content were identified through weighted gene coexpression network analysis. Additionally, the transcription level of some hub genes (PIF4, APRR2, bHLH128, ERF4, PSY1, LCYE2, and RCCR3) was highly correlated with pigment content in the peel, which may be responsible for carotenoid accumulation and chlorophyll degradation in the Y and O varieties. Taken together, the results obtained in this study help to provide a novel mechanism underlying peel colouration in zucchini.

SUBMITTER: Xu X

PROVIDER: S-EPMC8991947 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature

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Combined analysis of carotenoid metabolites and the transcriptome to reveal the molecular mechanism underlying fruit colouration in zucchini (<i>Cucurbita pepo</i> L.).

Xu Xiaoyong X Lu Xiaonan X Tang Zhongli Z Zhang Xiaoning X Lei Fengjin F Hou Leiping L Li Meilan M

Food chemistry. Molecular sciences 20210416

To reveal the molecular mechanism underlying peel colouration, carotenoid metabolites and the transcriptome were jointly analysed in zucchini peels with three different colours: light green (Lg), yellow (Y), and orange (O). Our results showed that the carotenoid levels in O (157.075 μg/g) and Y (22.734 μg/g) were both significantly higher than in Lg (7.435 μg/g), while the chlorophyll content was highest in Lg (32.326 μg/g), followed by O (7.294 μg/g) and Y (4.617 μg/g). A total of 14 carotenoid ...[more]

PMID: 35415627

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Project description:BackgroundZucchini fruit set can be limited due to unfavourable environmental conditions in off-seasons crops that caused ineffective pollination/fertilization. Parthenocarpy, the natural or artificial fruit development without fertilization, has been recognized as an important trait to avoid this problem, and is related to auxin signalling. Nevertheless, differences found in transcriptome analysis during early fruit development of zucchini suggest that other complementary pathways could regulate fruit formation in parthenocarpic cultivars of this species. The development of next-generation sequencing technologies (NGS) as RNA-sequencing (RNA-seq) opens a new horizon for mapping and quantifying transcriptome to understand the molecular basis of pathways that could regulate parthenocarpy in this species. The aim of the current study was to analyze fruit transcriptome of two cultivars of zucchini, a non-parthenocarpic cultivar and a parthenocarpic cultivar, in an attempt to identify key genes involved in parthenocarpy.ResultsRNA-seq analysis of six libraries (unpollinated, pollinated and auxin treated fruit in a non-parthenocarpic and parthenocarpic cultivar) was performed mapping to a new version of C. pepo transcriptome, with a mean of 92% success rate of mapping. In the non-parthenocarpic cultivar, 6479 and 2186 genes were differentially expressed (DEGs) in pollinated fruit and auxin treated fruit, respectively. In the parthenocarpic cultivar, 10,497 in pollinated fruit and 5718 in auxin treated fruit. A comparison between transcriptome of the unpollinated fruit for each cultivar has been performed determining that 6120 genes were differentially expressed. Annotation analysis of these DEGs revealed that cell cycle, regulation of transcription, carbohydrate metabolism and coordination between auxin, ethylene and gibberellin were enriched biological processes during pollinated and parthenocarpic fruit set.ConclusionThis analysis revealed the important role of hormones during fruit set, establishing the activating role of auxins and gibberellins against the inhibitory role of ethylene and different candidate genes that could be useful as markers for parthenocarpic selection in the current breeding programs of zucchini.

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Project description:Trichomes provide an excellent model for studying cell differentiation and proliferation. The aboveground tissues of plants with long dense trichomes (LDTs) can cause skin itching in people working in a zucchini field, in which management, pollination, and fruit harvesting are difficult. In this study, an F2 population was constructed with the LDT inbred line "16" and the sparse micro trichome (SMT) inbred line "63" for QTL analysis of type I and II trichome density. Two QTLs were identified on chromosomes 3 and 15 using the QTL-seq method. Additionally, 191 InDel markers were developed on 20 chromosomes, a genetic map was constructed for QTL mapping, and three QTLs were identified on chromosomes 3, 6, and 15. Two QTLs, CpTD3.1 and CpTD15.1, were identified in both QTL-seq and genetic map-based QTL analyses, and CpTD15.1 was the major-effect QTL. The stability of CpTD3.1 and CpTD15.1 was confirmed using data from F2 plants under different environmental conditions. The major-effect QTL CpTD15.1 was located between markers chr15-4991349 and chr15-5766791, with a physical distance of 775.44 kb, and explained 12.71%-29.37% of the phenotypic variation observed in the three environments. CpTD3.1 was located between markers chr3-218350 and chr3-2891236, in a region with a physical distance of 2,672.89 kb, and explained 5.00%-10.64% of the phenotypic variation observed in the three environments. The functional annotations of the genes within the CpTD15.1 region were predicted, and five genes encoding transcription factors regulating trichome development were selected. Cp4.1LG15g04400 encoded zinc finger protein (ZFP) and harbored nonsynonymous SNPs in the conserved ring finger domain between the two parental lines. There were significant differences in Cp4.1LG15g04400 expression between "16" and "63", and a similar pattern was found between germplasm resources of LDT lines and SMT lines. It was presumed that Cp4.1LG15g04400 might regulate trichome density in zucchini. These results lay a foundation for better understanding the density of multicellular nonglandular trichomes and the regulatory mechanism of trichome density in zucchini.

Dataset Information

Combined analysis of carotenoid metabolites and the transcriptome to reveal the molecular mechanism underlying fruit colouration in zucchini (Cucurbita pepo L.).

Publications

Combined analysis of carotenoid metabolites and the transcriptome to reveal the molecular mechanism underlying fruit colouration in zucchini (<i>Cucurbita pepo</i> L.).

Similar Datasets

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