Journal Article

Metabolome and transcriptome analyses reveal chlorophyll and anthocyanin metabolism pathway associated with cucumber fruit skin color

Jiang, Biao, Cao, Zhenqiang, Liang, Zhaojun, Peng, Qingwu, Chen, Lin, Wang, Min, Sun, Piaoyun, He, Xiaoming, Liu, Wenrui, Lin, Yu’e, Yan, Jinqiang

2020

Overview

Background Fruit skin color play important role in commercial value of cucumber, which is mainly determined by the content and composition of chlorophyll and anthocyanins. Therefore, understanding the related genes and metabolomics involved in composition of fruit skin color is essential for cucumber quality and commodity value. Results The results showed that chlorophyll a, chlorophyll b and carotenoid content in fruit skin were higher in Lv (dark green skin) than Bai (light green skin) on fruit skin. Cytological observation showed more chloroplast existed in fruit skin cells of Lv. A total of 162 significantly different metabolites were found between the fruit skin of the two genotypes by metabolome analysis, including 40 flavones, 9 flavanones, 8 flavonols, 6 anthocyanins, and other compounds. Crucial anthocyanins and flavonols for fruit skin color, were detected significantly decreased in fruit skin of Bai compared with Lv. By RNA-seq assay, 4516 differentially expressed genes (DEGs) were identified between two cultivars. Further analyses suggested that low expression level of chlorophyll biosynthetic genes, such as chlM , por and NOL caused less chlorophylls or chloroplast in fruit skin of Bai. Meanwhile, a predicted regulatory network of anthocyanin biosynthesis was established to illustrate involving many DEGs, especially 4CL , CHS and UFGT . Conclusions This study uncovered significant differences between two cucumber genotypes with different fruit color using metabolome and RNA-seq analysis. We lay a foundation to understand molecular regulation mechanism on formation of cucumber skin color, by exploring valuable genes, which is helpful for cucumber breeding and improvement on fruit skin color.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Agriculture / Analysis / Anthocyanin / Anthocyanins / Anthocyanins - genetics / Anthocyanins - metabolism / Biomedical and Life Sciences / Biosynthesis / Carotenoids / Chlorophyll / Chlorophyll A - genetics / Chlorophyll A - metabolism / Chloroplasts / Color / Composition / cucumbers / Cucumis sativus - genetics / Cucumis sativus - metabolism / Cucumis sativus L / Cultivars / Enzymes / flavanones / Flavones / Flavonoids / Flavonols / Fruit - genetics / Fruit - metabolism / fruit color / fruit composition / Fruits / Gene expression / gene expression regulation / Genes / Genetic research / Genetics and crop biotechnology / Genomes / Genotypes / Life Sciences / Metabolism / Metabolites / Metabolome / Metabolomics / Physiological aspects / Pigments / Plant breeding / Plant Sciences / Principal components analysis / Research Article / Ribonucleic acid / RNA / RNA sequencing / RNA-Seq / sequence analysis / Skin / Transcription factors / Transcriptome / Tree Biology / Vegetables