DoRWA3 from Dendrobium officinale Plays an Essential Role in Acetylation of Polysaccharides

• Published in: International journal of molecular sciences 2020-08, Vol.21 (17), p.6250
• Main Authors: Si, Can, Teixeira da Silva, Jaime A, He, Chunmei, Yu, Zhenming, Zhao, Conghui, Wang, Haobin, Zhang, Mingze, Duan, Jun
• Format: Article
• Language: English
• Subjects: Abscisic acid; Abscisic Acid - pharmacology; acetyl groups; Acetylation; Acetyltransferase; Bioinformatics; Biological activity; Biological properties; Cloning, Molecular; Deacetylation; Dendrobium - drug effects; Dendrobium - growth & development; Dendrobium officinale; Endoplasmic reticulum; Endoplasmic Reticulum - metabolism; Gene Expression Regulation, Plant - drug effects; Genes; Genomes; Genotype & phenotype; Germination; Germination - drug effects; Herbal medicine; Molecular weight; Organs; Phylogeny; Physical properties; Plant Leaves - drug effects; Plant Leaves - growth & development; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - drug effects; Plant Roots - physiology; Polysaccharides; Polysaccharides - metabolism; Proteins; REDUCED WALL ACETYLATION; Seeds; Sequence Analysis, DNA; Transcription; Transgenic plants
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21176250

The acetylation or deacetylation of polysaccharides can influence their physical properties and biological activities. One main constituent of the edible medicinal orchid, , is water-soluble polysaccharides (WSPs) with substituted -acetyl groups. Both -acetyl groups and WSPs show a similar trend in different organs, but the genes coding for enzymes that transfer acetyl groups to WSPs have not been identified. In this study, we report that REDUCED WALL ACETYLATION (RWA) proteins may act as acetyltransferases. Three genes were identified, cloned, and sequenced. They were sensitive to abscisic acid (ABA), but there were no differences in germination rate and root length between wild type and transgenic lines under ABA stress. Three DoRWA proteins were localized in the endoplasmic reticulum. had relatively stronger transcript levels in organs where acetyl groups accumulated than and , was co-expressed with polysaccharides synthetic genes, so it was considered as a candidate acetyltransferase gene. The level of acetylation of polysaccharides increased significantly in the seeds, leaves and stems of three transgenic lines compared to wild type plants. These results indicate that DoRWA3 can transfer acetyl groups to polysaccharides and is a candidate protein to improve the biological activity of other edible and medicinal plants.