Location: Grape Genetics Research Unit (GGRU)Title: Effects of sunlight on anthocyanin accumulation and associated co-expression gene networks in developing grape berries
|ZOU, LUMING - Chinese Academy Of Sciences|
|WU, BENHONG - Chinese Academy Of Sciences|
|LI, SHAOHUA - Chinese Academy Of Sciences|
|LIANG, ZHENCHANG - Chinese Academy Of Sciences|
Submitted to: Environmental and Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2019
Publication Date: 7/2/2019
Citation: Zou, L., Zhong, G., Wu, B., Yang, Y., Li, S., Liang, Z. 2019. Effects of sunlight on anthocyanin accumulation and associated co-expression gene networks in developing grape berries. Environmental and Experimental Botany. 166. https://doi.org/10.1016/j.envexpbot.2019.103811.
Interpretive Summary: Anthocyanins are purple natural pigments and play significant roles in human health. Anthocyanin levels in grape berry skin are one of the most important criteria to assess grape quality. Anthocyanin contents in grape berries highly depend on environmental factors. Among environmental factors, sunlight is a critical stimulus that regulates anthocyanin accumulation. Anthocyanin contents decrease when grapes are not exposed to sunlight and can be reduced even under shaded conditions in grapes. In some cultivars, such as V. vinifera ‘Jingxiu,’ anthocyanin biosynthesis is completely inhibited in the absence of sunlight. However, in sunlight-independent V. vinifera ‘Jingyan,’ anthocyanins accumulate in berries under dark conditions. The genetic mechanism for this difference is unknown. In this study, we investigated gene expression profiles of berry samples at different developmental stages from three different Vitis species under light-exposure and light-shade treatments. We found many genes differentially expressed and expression networks differentially regulated. This study is the first to construct a weighted gene co-expression network to examine the effects of sunlight on anthocyanin biosynthesis in grape berries. The data from the study serve as a valuable resource for further research on sunlight-dependent and sunlight-independent processes in grape berries.
Technical Abstract: Three Vitis species were used to investigate the effects of sunlight exposure on anthocyanin accumulation in five developmental stages. The berries of these three grapes were treated with exclusion of sunlight or recovery of sunlight during different developmental stages. Vitis labrusca cannot accumulate anthocyanins in its berries under dark conditions. V. acerifolia and V. cinerea can accumulate anthocyanins under dark conditions. Using high-throughput RNA sequencing, we produced transcriptomes for these samples. Then, we constructed a weighted gene co-expression network of these three Vitis species and defined 17 modules which were correlated to anthocyanin concentrations, developmental stages and species. Analysis of the anthocyanin correlated co-expression network module revealed that two novel bHLH genes might be involved in anthocyanin regulation in grapes. Moreover, the hormone transductions might enhance anthocyanin accumulation in V. acerifolia and V. cinerea under dark. Further functional analysis of anthocyanin negatively correlated modules revealed that anthocyanin accumulation might be inhibited by COP1-dependent protein degradation before veraison and under dark conditions in grape berries.