摘要
Wood is produced by the accumulation of secondary xylem via proliferation and differentiation of the cambium cells in woody plants. Identifying the regulators involved in this process remains a challenging task. In this study, we isolated Pag SAG101 a,the homolog of Arabidopsis thaliana SAG101, from a hybrid poplar(Populus alba × Populus glandulosa)clone 84 K and investigated its role in secondary xylem development. Pag SAG101 a was expressed predominantly in lignified stems and localized in thenucleus. Compared with non-transgenic 84 K plants,transgenic plants overexpressing Pag SAG101 a displayed increased plant height, internode number,stem diameter, xylem width, and secondary cell wall thickness, while opposite phenotypes were observed for Pag SAG101 a knock-out plants.Transcriptome analyses revealed that differentially expressed genes were enriched for those controlling cambium cell division activity and subsequent secondary cell wall deposition during xylem formation.In addition, the tandem CCCH zinc finger protein Pag C3 H17, which positively regulates secondary xylem width and secondary wall thickening in poplar, could bind to the promoter of Pag SAG101 a and mediate the regulation of xylem differentiation.Our results support that Pag SAG101 a, downstream of Pag C3 H17, functions in wood development.
基金
supported by the Fundamental Research Funds of CAF(CAFYBB2017ZY001)
the Ten-thousand Talents Program of China to Meng-Zhu Lu。
