Identification of WUSCHEL-related homeobox gene and truncated small peptides in transformation efficiency improvement in Eucalyptus

Abstract

Background The WUSCHEL-related Homeobox (WOX) genes, which encode plant-specific homeobox (HB) transcription factors, play crucial roles in regulating plant growth and development. However, the functions of WOX genes are little known in Eucalyptus, one of the fastest-growing tree resources with considerable widespread cultivation worldwide. Results A total of nine WOX genes named EgWOX1-EgWOX9 were retrieved and designated from Eucalyptus grandis. From the three divided clades marked as Modern/WUS, Intermediate and Ancient, the largest group Modern/WUS (6 EgWOXs) contains a specific domain with 8 amino acids: TLQLFPLR. The collinearity, cis-regulatory elements, protein-protein interaction network and gene expression analysis reveal that the WUS proteins in E. grandis involve in regulating meristems development and regeneration. Furthermore, by externally adding of truncated peptides isolated from WUS specific domain, the transformation efficiency in E. urophylla × E. grandis DH32-29 was significant enhanced. The transcriptomics data further reveals that the use of small peptides activates metabolism pathways such as starch and sucrose metabolism, phenylpropanoid biosynthesis and flavonoid biosynthesis. Conclusions Peptides isolated from WUS protein can be utilized to enhance the transformation efficiency in Eucalyptus, thereby contributing to the high-efficiency breeding of Eucalyptus.

The Evolution of the WUSCHEL-Related Homeobox Gene Family in Dendrobium Species and Its Role in Sex Organ Development in D. chrysotoxum

“…Supported by the conserved motifs and intron patterns, the highly conserved gene structure guarantees the conserved function of each clade or subclade. WOX genes in the same subfamily tend to have similar numbers of introns and exons, and they also share similarities in gene structure (Figure 3) [50,51]. The gene of the ancient clade has a more conserved gene structure than the other two clades' genes, consistent with the WOX genes of Arabidopsis, Poplar, and Sorghum [37].…”

Identification and Expression Profile Analysis of WOX Family Genes in the Formation of Eucalyptus Adventitious Root

“…The root development of woody plants is a very complex process. Hence, it is crucial to understand the molecular mechanisms underlying primordial, lateral, and adventitious roots to improve the efficiency of the root regeneration system in histoculture and to conduct an in-depth study of plant regeneration [4]. Numerous studies have revealed that the WOX gene family plays an important regulatory role in the critical period of plant rooting [5,6,[9][10][11][12][13]17].…”

“…Members of the WOX family and endogenous cytokines and growth hormones play a key role in regulating the formation and maintenance of healing tissue. WOX11 is a key gene involved in growth hormone response and cell fate transition, and the expression of WOX11 transforms regeneration-competent cells into adventitious root founder cells [4,32]. The OsADA2-OsGCN5 complex was identified as a WOX11-interacting partner and was shown to activate the expression of downstream genes to maintain the cell division rate [33].…”

“…The WUSCHEL-related homeobox (WOX) is a family of plant-specific transcription factors, and the prototypical members of the plant-specific WUSCHEL-related homeobox (WOX) protein family, all of which contain the conserved structural domains of the homology box (HB) and are part of the HB superfamily [3]. The structural domains of the WOX gene family have a helix-loop-helix-turn-helix (HTH) structure, which contains 60-66 amino acids essential for specific functions in plants [4]. Based on the phylogenetic analysis of WOX proteins, the WOX family is classified into three clades: the ancient clade, the intermediate clade, and the modern/WUS clade [4].…”

“…The structural domains of the WOX gene family have a helix-loop-helix-turn-helix (HTH) structure, which contains 60-66 amino acids essential for specific functions in plants [4]. Based on the phylogenetic analysis of WOX proteins, the WOX family is classified into three clades: the ancient clade, the intermediate clade, and the modern/WUS clade [4]. Previous studies have demonstrated that WOX genes play an important role in plant growth and development.…”