Sucrose Enhances Anthocyanin Accumulation in Torenia by Promoting Expression of Anthocyanin Biosynthesis Genes

Aung Htay Naing,Kyeung Il Park,Chang Kil Kim,Mi Young Chung,Junping Xu

doi:10.3390/horticulturae7080219

Abstract

We examined the effects of different sucrose concentrations (3%, 5%, and 7%) on anthocyanin accumulation and plant growth in wild type (WT) and transgenic (T2) torenia cultivar “Kauai Rose” overexpressing the anthocyanin regulatory transcription factors B-Peru + mPAP1 or RsMYB1. Sucrose increased anthocyanin production in both WT and transgenic plants, with higher anthocyanin production in transgenic plants compared to WT plants. Higher sucrose concentrations increased production of anthocyanin in transgenic and WT plants, with increased anthocyanin production associated with increased expression of anthocyanin biosynthesis genes. Higher sucrose concentrations reduced growth of WT and transgenic plants. Our results indicate that sucrose enhances anthocyanin production in torenia by regulating anthocyanin biosynthesis genes.

Highlights

Anthocyanins are responsible for pigmentation of vegetative and reproductive organs of many plant species
Accumulation of anthocyanin was observed in transgenic and wild type (WT) plants cultured in MS medium containing different concentrations of sucrose (3%, 5%, or 7%)
These results indicate sucrose is involved in the regulation of anthocyanin synthesis in a concentration-dependent manner and its effects vary between torenia plant lines

Summary

Introduction

Anthocyanins are responsible for pigmentation (ranging in colors from red to purple) of vegetative (leaf, stem, and roots) and reproductive (flower and fruit) organs of many plant species. Increased anthocyanin production in response to sugar has been demonstrated in flowers, fruits, and vegetative tissues [5,6,7,8,9,10,11,12,13,14,15,16]. Exogenous sucrose and accumulation of endogenous sugar have been shown to increase expression of early and late anthocyanin biosynthesis genes (EBGs and LBGs), including chalcone synthase (CHS), dihydroflavonol reductase (DFR), and anthocyanidin synthase (ANS), in grape, petunia, and radish [5,6,15,16]. Sucrose has been shown to increase levels of MYB75/PAP1, a transcription factor (TF)

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Conclusion