Characterization of and during Callus and Root Induction in the Shrub Species .

Plant regeneration and the underlying molecular regulatory network are of great interest to developmental biology, and have potential applications in agriculture and biotechnology. Cell growth and re-differentiation during organogenesis require the activation and reprogramming of stem cells within the stem cell niche of the tissues. The WUSCHEL-related homeobox (WOX) factors play important roles in the maintenance and regulation of plant stem cells and are involved in many developmental processes. However, in woody species such as the little is known about the involvement of genes in organogenesis. Here we show that two , and , are implicated in callus proliferation and root regeneration, respectively. The expression of both, together with another member , are upregulated during later stage of callus formation. The is associated with callus proliferation, or cell division during the redifferentiation. The overexpression of this gene results in up-regulation of and another homeobox gene. The plays a role in root primordium initiation, as its overexpression leads to more rooty calli and more roots per callus. also possibly acts upstream of and transcriptionally. Our results provide further evidence regarding the functions of genes in organogenesis in a woody plant.