WUSCHEL controls genotype-dependent shoot regeneration capacity in potato

Abstract

Plant cells can reprogram their fate. The combinatorial actions of auxin and cytokinin dedifferentiate somatic cells to regenerate organs, which can develop into individual plants. As transgenic plants can be generated from genetically modified somatic cells through these processes, cell fate transition is an unavoidable step in crop genetic engineering. However, regeneration capacity closely depends on the genotype, and the molecular events underlying these variances remain elusive. In the present study, we demonstrated that WUSCHEL (WUS) —a homeodomain transcription factor—determines regeneration capacity in different potato (Solanum tuberosum) genotypes. Comparative analysis of shoot regeneration efficiency and expression of genes related to cell fate transition revealed that WUS expression coincided with regeneration rate in different potato genotypes. Moreover, in a high-efficiency genotype, WUS silencing suppressed shoot regeneration. Meanwhile, in a low-efficiency genotype, regeneration could be enhanced through the supplementation of a different type of cytokinin that promoted WUS expression. Computational modeling of cytokinin receptor-ligand interactions suggested that the docking pose of cytokinins mediated by hydrogen bonding with the core residues may be pivotal for WUS expression and shoot regeneration in potatoes. Furthermore, our whole genome sequencing analysis revealed core sequence variations in the WUS promoters that differentiate low- and high-efficiency genotypes. The present study revealed that cytokinin responses, particularly WUS expression, determine shoot regeneration efficiency in different potato genotypes.

A Model of the Full-Length Cytokinin Receptor: New Insights and Prospects

“…AlphaFold 2 has already been used to construct models of potato StHK2-4 CK receptors. However, SM rather than full-length receptors were obtained, as the focus of the above study was on the active site and interaction with ligands [58]. The AlphaFold Protein Structure Database (https:// alphafold.ebi.ac.uk/download, accessed on 17 October 2023) [59] contains files of predicted structures for the proteomes of 16 model organisms, including plants such as A. thaliana, Oryza sativa, and Zea mays.…”

Overexpression of HbGRF4 or HbGRF4-HbGIF1 Chimera Improves the Efficiency of Somatic Embryogenesis in Hevea brasiliensis

“…Substantial improvements in somatic embryogenesis and de novo organogenesis have been achieved in a number of plant species by overexpressing several plant developmental regulators, including WUSCHEL (WUS), BABY BOOM (BBM), and GROWTH-REGULATING FACTOR-GRF-INTERACTING FACTOR (GRF-GIF) [ 26 , 27 , 28 , 29 ]. Overexpression of WUS and BBM promotes the regeneration of various transformation-recalcitrant plant genotypes, but constitutive expression of these two genes induced pleiotropic negative phenotypes, like sterility and severe dwarfism.…”