Journal Article

Expression of the MYB transcription factor gene BplMYB46 affects abiotic stress tolerance and secondary cell wall deposition in Betula platyphylla

Wang, Yucheng, Wang, Yanmin, Wang, Liuqiang, Zhang, Chunrui, Yang, Chuanping, Wang, Chao, Zhang, Yu, Hu, Ping, Jia, Yuanyuan, Zhang, Yiming, Guo, Huiyan

2017

Overview

Summary Plant MYB transcription factors control diverse biological processes, such as differentiation, development and abiotic stress responses. In this study, we characterized BplMYB46, an MYB gene from Betula platyphylla (birch) that is involved in both abiotic stress tolerance and secondary wall biosynthesis. BplMYB46 can act as a transcriptional activator in yeast and tobacco. We generated transgenic birch plants with overexpressing or silencing of BplMYB46 and subjected them to gain‐ or loss‐of‐function analysis. The results suggest that BplMYB46 improves salt and osmotic tolerance by affecting the expression of genes including SOD, POD and P5CS to increase both reactive oxygen species scavenging and proline levels. In addition, BplMYB46 appears to be involved in controlling stomatal aperture to reduce water loss. Overexpression of BplMYB46 increases lignin deposition, secondary cell wall thickness and the expression of genes in secondary cell wall formation. Further analysis indicated that BplMYB46 binds to MYBCORE and AC‐box motifs and may directly activate the expression of genes involved in abiotic stress responses and secondary cell wall biosynthesis whose promoters contain these motifs. The transgenic BplMYB46‐overexpressing birch plants, which have improved salt and osmotic stress tolerance, higher lignin and cellulose content and lower hemicellulose content than the control, have potential applications in the forestry industry.

• Publisher: John Wiley & Sons, Inc,John Wiley and Sons Inc
• Subject: Abiotic stress / Analysis / Apertures / Arabidopsis - genetics / Betula - genetics / Betula pendula subsp. mandshurica / Betula platyphylla / Biological activity / Biosynthesis / BplMYB46 / Cell cycle / Cell Death / Cell Nucleus / Cell Wall - chemistry / Cell Wall - metabolism / Cell walls / Cellulose / Cellulose - metabolism / Deoxyribonucleic acid / DNA / DNA binding proteins / Forestry / Function analysis / Gene expression / Gene Expression Regulation, Plant - genetics / Gene Knockdown Techniques / Gene Silencing / Genes / Genetic aspects / Genetic engineering / Genetic research / Genetic Vectors / Hemicellulose / Lignin / Lignin - metabolism / loss-of-function mutation / MYB gene / Onions - cytology / Onions - genetics / Osmotic Pressure / Osmotic stress / osmotolerance / peroxidase / Physiological aspects / Plant Proteins - genetics / Plant Stomata - genetics / Plant Stomata - metabolism / Plants / Plants, Genetically Modified - metabolism / Polysaccharides - metabolism / Proline / Protein Binding / Proteins / Reactive oxygen species / Reactive Oxygen Species - metabolism / Salinity / Salinity tolerance / Salt-Tolerance - genetics / Scanning electron microscopy / Scavenging / secondary wall deposition / Signal transduction / Sodium Chloride - metabolism / Stomata / stomatal movement / stress response / stress tolerance / Stress, Physiological - genetics / superoxide dismutase / Tobacco / transactivators / Transcription factors / Transcription Factors - genetics / Transcriptional Activation - genetics / Transgenic plants / Wall deposition / Wall thickness / Water / Water loss / Xylem - cytology / Xylem - genetics / Yeast / yeasts