Integrative Analysis of Metabolome and Transcriptome Reveals the Mechanism of Color Formation in Liriope spicata Fruit.

Sichen Gan,Shoukuo Zhu,Jieyu Qian,Gang Zheng,Lijun Liang

doi:10.3390/metabo12020144

Sichen Gan, Shoukuo Zhu + Show 3 more

Open Access

https://doi.org/10.3390/metabo12020144

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Journal: Metabolites	Publication Date: Feb 4, 2022
Citations: 5	License type: CC BY 4.0

Affiliation: Zhejiang A & F University

Abstract

Liriope spicata is an important ornamental ground cover plant, with a fruit color that turns from green to black during the development and ripening stages. However, the material basis and regulatory mechanism of the color variation remains unclear. In this study, a total of 31 anthocyanins and 2 flavonols were identified from the skin of L. spicata fruit via integrative analysis on the metabolome and transcriptome of three developmental stages. The pigments of black/mature fruits are composed of five common anthocyanin compounds, of which Peonidin 3–O–rutinoside and Delphinidin 3–O–glucoside are the most differential metabolites for color conversion. Using dual-omics joint analysis, the mechanism of color formation was obtained as follows. The expression of structural genes including 4CL, F3H, F3′H, F3′5′H and UFGT were activated due to the upregulation of transcription factor genes MYB and bHLH. As a result, a large amount of precursor substances for the synthesis of flavonoids accumulated. After glycosylation, stable pigments were generated which promoted the accumulation of anthocyanins and the formation of black skin.

Highlights

Anthocyanins belong to flavonoid compounds, generally sourced from secondary metabolites
The increased ratio of Cyanidin/Pelargonidin in Zea mays has been reported to be the key reason for the purple tint in red grains [2]
This study expounded on the material basis and molecular regulation mechanisms for the color formation of L. spicata fruit

Summary

Introduction

Anthocyanins belong to flavonoid compounds, generally sourced from secondary metabolites. Their basic structure contains two aromatic rings and one heterocyclic ring. Anthocyanins generally present different colors due to their functional groups, for example, Pelargonidin displays orange and Cyanidin and Peonidin show red/pink, while Delphinidin, Malvidin and Petunidin demonstrate blue/purple [1]. The color of the plant organ is not formed from single pigment, but from a variety of anthocyanin compounds. Various anthocyanins, which accumulate in the epidermic cells in different proportions, generally influence the final color of the organ. The increased ratio of Cyanidin/Pelargonidin in Zea mays has been reported to be the key reason for the purple tint in red grains [2]

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