Two WUSCHEL‐related HOMEOBOX genes, PeWOX11a and PeWOX11b, are involved in adventitious root formation of poplar

Abstract

The plant-specific WUSCHEL-related HOMEOBOX (WOX) transcription factors play important roles in key developmental processes, but knowledge regarding functional characterization of WOX genes in poplar remains limited. To reveal genes and signaling pathways associated with adventitious rooting in poplar, here we isolated and characterized two WOX genes through the rapid amplification of cDNA ends (RACE), sequence aligning, expression profiling, protoplast transfection and poplar transformation. Detailed information about the sequence similarity, structural features, evolutionary relationships, expression patterns and subcellular localization of the two genes were revealed. Overexpression of either PeWOX11a or PeWOX11b not only increased the number of adventitious roots on the cuttings but also induced ectopic roots in the aerial parts of transgenic poplars. Meanwhile, their overexpression in transgenic poplars affected axillary bud and leaf development. These results suggest that PeWOX11a and PeWOX11b were involved in multiple developmental processes of poplar, especially in adventitious root formation. Our results provide new insights into the molecular mechanisms underlying adventitious root formation of poplar.

Control of adventitious root formation: insights into synergistic and antagonistic hormonal interactions

“…The Populus (cultivar ‘Nanline895’) genome contains two WOX11 paralogs: PeWOX11a and PeWOX11b . Xu et al () found that constitutive overexpression of PeWOX11 in transgenic lines not only enhanced the rate of rooting, but also increased numbers of ARs per cutting. In conclusion, the closely related homologs of AtWOX11 in rice and Populus are required for proper AR formation, suggesting that WOX11 likely mediates a conserved evolutionary mechanism of adventitious rooting in monocots and dicots, including woody species (Zhao et al , Xu et al ).…”

Comprehensive analysis of dynamic gene expression and investigation of the roles of hydrogen peroxide during adventitious rooting in poplar

“…Subsequently, a transcription factor in the AP2 family was also found to play a role during AR formation [28]. Several WUSCHEL-related HOMEOBOX (WOX) transcription factors have also been reported to regulate key developmental processes in AR formation in poplar [29,30]. However, there is still insufficient understanding of poplar AR formation compared with that of AR formation in herbaceous model plants.…”

Selection of Reliable Reference Genes for Gene Expression Analysis under Abiotic Stresses in the Desert Biomass Willow, Salix psammophila

“…An ideal RG should be stable expressed in different tissue types, development stages and under different experimental conditions. Then, housekeeping genes involved in basic cellular processes are used as representative of the traditional internal RGs in many studies, such as ACT ( Actin ), TUB ( Tubulin ), 18S ( 18S ribosomal RNA ), UBC ( Ubiquitin-conjugating enzyme ), EF1 α ( Elongation factor-1 alpha ) ( Fiume and Fletcher, 2012 ; Mousavi et al, 2013 ; Sakuraba et al, 2014 ; Tian H. et al, 2015 ; Xu et al, 2015 ; Liu et al, 2016 ). However, many studies also show that housekeeping genes have been not stably expressed under any tissues and all experimental conditions ( Schmittgen and Zakrajsek, 2000 ; Jain et al, 2006 ; Hong et al, 2008 ; Wang et al, 2014 ; Xu et al, 2016 ).…”