Biochemical and Expression Analyses Revealed the Involvement of Proanthocyanidins and/or Their Derivatives in Fiber Pigmentation of Gossypium stocksii

• Published in: International journal of molecular sciences 2022-01, Vol.23 (2), p.1008
• Main Authors: Sun, Yujie, Zhang, Diandian, Zheng, Hongli, Wu, Yuqing, Mei, Jun, Ke, Liping, Yu, Dongliang, Sun, Yuqiang
• Format: Article
• Language: English
• Subjects: Accumulation; Anthocyanidin reductase; Biosynthesis; Biosynthetic Pathways; Cellulose; Cloning, Molecular; Coloration; Cotton; Cotton fibers; Elongation; Fibers; Flavonoids; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Plant; Genes; Genomes; Gossypium; Gossypium - genetics; Gossypium - growth & development; Gossypium - metabolism; Molecular modelling; Oxidoreductases - genetics; Pigmentation; Plant Proteins - genetics; Proanthocyanidins; Proanthocyanidins - genetics; Proanthocyanidins - metabolism; Reductases; Transcription factors; Transcription Factors - genetics; Transcriptomics; Up-Regulation
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23021008

The wild cotton species produces a brown fiber that provides a valuable resource for the color improvement of naturally colored cotton (NCC) fiber. However, the biochemical basis and molecular mechanism of its fiber pigmentation remain unclear. Herein, we analyzed the dynamics of proanthocyanidins (PAs) accumulation in developing the fiber of , which suggested a similar role of PAs and/or their derivatives in the fiber coloration of . In addition, comparative transcriptomics analyses revealed that the PA biosynthetic genes were expressed at higher levels and for a longer period in developing fibers of than (white fiber), and the transcription factors, such as TT8, possibly played crucial regulatory roles in regulating the PA branch genes. Moreover, we found that the anthocyanidin reductase (ANR) was expressed at a higher level than the leucoanthocyanidin reductases (LARs) and significantly upregulated during fiber elongation, suggesting a major role of ANR in PA synthesis in fiber. In summary, this work revealed the accumulation of PAs and the expression enhancement of PA biosynthetic genes in developing fibers of . We believe this work will help our understanding of the molecular mechanisms of cotton fiber coloration and further promote the future breeding of novel NCCs.