Objective To analyze the effects of PagWOX11/12a gene on the growth and development of poplar for further research on the regulation mechanism of this gene in woody plants.

Method Bioinformatics methods and software were used to construct phylogenetic evolutionary tree, sequence alignment and biochemical characterization analysis. Tissue-specific expression patterns were analyzed by qRT-PCR. The phenotype of poplar after specifically suppressed the expression of PagWOX11/12a was analyzed by using transgenic plant 35S::PagWOX11/12a-SRDX (DR).

Result PagWOX11/12a gene could encode a protein with 255 amino acids, which was expressed in different tissues of 84K. The phenotypic analysis of DR transgenic plants showed that inhibiting the expression of this gene could reduce the length of phloem cells, pith cells and xylem fiber cells, inhibit internode elongation, and significantly reduced plant height compared with non-transgenic 84K.

Conclusion PagWOX11/12a gene participates in regulating the height growth of poplar by affecting the elongation of internodes. This study provides a reference for further revealing the regulatory mechanism of PagWOX11/12a gene involved in the growth and development of poplar.