Integrated metabolic profiling and transcriptome analysis of pigment accumulation in Lonicera japonica flower petals during colour-transition

Abstract

Background Plants have remarkable diversity in petal colour through the biosynthesis and accumulation of various pigments. To better understand the mechanisms regulating petal pigmentation in Lonicera japonica, we used multiple approaches to investigate the changes in carotenoids, anthocyanins, endogenous hormones and gene expression dynamics during petal colour transitions, i.e., green bud petals (GB_Pe), white flower petals (WF_Pe) and yellow flower petals (YF_Pe). Results Metabolome analysis showed that YF_Pe contained a much higher content of carotenoids than GB_Pe and WF_Pe, with α-carotene, zeaxanthin, violaxanthin and γ-carotene identified as the major carotenoid compounds in YF_Pe. Comparative transcriptome analysis revealed that the key differentially expressed genes (DEGs) involved in carotenoid biosynthesis, such as phytoene synthase, phytoene desaturase and ζ-carotene desaturase, were significantly upregulated in YF_Pe. The results indicated that upregulated carotenoid concentrations and carotenoid biosynthesis-related genes predominantly promote colour transition. Meanwhile, two anthocyanins (pelargonidin and cyanidin) were significantly increased in YF_Pe, and the expression level of an anthocyanidin synthase gene was significantly upregulated, suggesting that anthocyanins may contribute to vivid yellow colour in YF_Pe. Furthermore, analyses of changes in indoleacetic acid, zeatin riboside, gibberellic acid, brassinosteroid (BR), methyl jasmonate and abscisic acid (ABA) levels indicated that colour transitions are regulated by endogenous hormones. The DEGs involved in the auxin, cytokinin, gibberellin, BR, jasmonic acid and ABA signalling pathways were enriched and associated with petal colour transitions. Conclusion Our results provide global insight into the pigment accumulation and the regulatory mechanisms underlying petal colour transitions during the flower development process in L. japonica.

Global Transcriptome Analysis Revealed the Molecular Regulation Mechanism of Pigment and Reactive Oxygen Species Metabolism During the Stigma Development of Carya cathayensis

“…From opening to mature, the stigma color presents successively green, light-purple red, dark-purple red, dark purple ( Figure 1A ). Chlorophylls, carotenoids, and anthocyanins are three chemically diverse groups of pigments and the core members in flower color formation ( Xue et al, 2020 ; Xia et al, 2021 ). Our present work showed that the stigma appeared green at the first stage (S1) when the chlorophyll content was higher than the other two pigments, gradually turning red and purple as the anthocyanin and carotenoid content increased (S2 to S3), and eventually getting dark purple due to the reduction of carotenoid content and sharp increase of anthocyanin content of from S3 to S4 ( Figures 1A–D ).…”

“…Flower color plays an essential function in plant ecology and evolution by attracting animal pollinators ( Grotewold, 2006 ), being a central feature of plant observation, and having a significant ornamental function ( Xue et al, 2020 ). Due to the importance of color formation in angiosperm, especially in the ornamental plant, the biosynthetic pathways of pigment in color formation have been widely reported ( Grotewold, 2006 ; Chen et al, 2016 ; Xia et al, 2021 ). Three chemically distinct groups of pigments, chlorophylls, carotenoids, and anthocyanins are widely distributed in plants and are the major pigments in flower color formation ( Xue et al, 2020 ; Xia et al, 2021 ).…”

“…Due to the importance of color formation in angiosperm, especially in the ornamental plant, the biosynthetic pathways of pigment in color formation have been widely reported ( Grotewold, 2006 ; Chen et al, 2016 ; Xia et al, 2021 ). Three chemically distinct groups of pigments, chlorophylls, carotenoids, and anthocyanins are widely distributed in plants and are the major pigments in flower color formation ( Xue et al, 2020 ; Xia et al, 2021 ).…”

Effects of Different Chemicals on Sexual Regulation in Persimmon (Diospyros kaki Thunb.) Flowers

“…Factors such as drought, temperature, salinity, and phytohormones extensively contribute to plant growth and development, inducing various morphological, physiological, and biochemical responses ( Utsumi et al, 2019 ; Li F. et al, 2020 ). Metabolomics data can connect genomic and phenotypic manifestations ( Xia et al, 2021 ). For plants, survival in different conditions requires substantial metabolic changes, which are reflected by extensive transcriptional level changes that occur during exposure to stress ( Janiak et al, 2018 ).…”

Integrated metabolomics and transcriptome analysis on flavonoid biosynthesis in flowers of safflower (Carthamus tinctorius L.) during colour-transition

“…Recently, analysis of the metabolomics combined with the transcriptome had widely used in revealing the mechanisms of many important physiological processes ( Scossa, Alseekh & Fernie, 2021 ; Xia et al, 2021 ; Zou et al, 2021 ). In research on Lonicera japonica Thunb, integrated metabolomics and transcriptome analysis of pigment accumulation in Lonicera japonica flower petals during colour transition revealed changes in key pigments and related biosynthesis genes associated with petal colour transitions ( Xia et al, 2021 ). Besides, in our previously research, through integrated metabolomics and transcriptome methods, we analyze the molecular mechanism of flavonoid biosynthesis under MeJA treatment in safflower ( Chen et al, 2020 ).…”