AUTHOR=Shao Dongnan , Zhu Qian-hao , Liang Qian , Wang Xuefeng , Li Yanjun , Sun Yuqiang , Zhang Xinyu , Liu Feng , Xue Fei , Sun Jie 

TITLE=Transcriptome Analysis Reveals Differences in Anthocyanin Accumulation in Cotton (Gossypium hirsutum L.) Induced by Red and Blue Light

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.788828

DOI=10.3389/fpls.2022.788828

ISSN=1664-462X

ABSTRACT=Many factors affect anthocyanin biosynthesis and accumulation, among which illumination is an important environmental factor. In the process of photoinduced anthocyanin biosynthesis, the difference of light quality is the key factor affecting the synthesis and accumulation of anthocyanins. In this study, we found that the red color of the Upland cotton accession Huiyuan with the R1 mutation turned to normal green color under light-emitting diodes (LEDs), which inspired us to investigate the effect of red and blue lights on the biosynthesis and accumulation of anthocyanins. We found that both red and blue lights elevated accumulation of anthocyanins. Comparative transcriptomic analyses, including GO, KEGG and GSEA, revealed that genes differentially expressed under different light conditions were enriched with the pathways of circadian rhythm, phenylpropanoid biosynthesis, anthocyanin biosynthesis, and flavone and flavonol biosynthesis. Not surprisingly, all the major structural genes related to biosynthesis of anthocyanins, including the key regulatory MYB transcription factor (GhPAP1D) and anthocyanin transporter (GhGSTF12), were induced by both red and blue light treatments. However, the genes (LARs and MATEs) related to biosynthesis of proanthocyanidins were more significantly up-regulated under red light radiation compared with blue light, and the accumulation of anthocyanins under red light was not as high as that under blue light, suggesting a role of light quality in directing of substrates towards biosynthesis of proanthocyanidins and anthocyanins. In addition, we demonstrated a potential role of GhHY5, a key regulator in plant circadian rhythms, in regulation of anthocyanin accumulation, which could be achieved via interaction with GhPAP1D. Together, these results indicate different effect of red and blue lights on biosynthesis and accumulation of anthocyanins and a potential module including GhHY5 and GhPAP1D in regulation of anthocyanin accumulation in cotton.