WUS and PIN1-related genes undergo dynamic expressional change during organ regeneration in response to wounding in Zoysia japonica.

Zoysia japonica is a grass specie used for golf courses and stadium lawns because of its eminent organ regeneration ability after cutting. However, the molecular mechanisms of the organ regeneration remain elusive. In plants, the shoot apical meristem (SAM) plays a critical role in organ regeneration process. Studies on shoot apical meristem (SAM) in Arabidopsis revealed PIN-FORMED 1 (PIN1) and WUSCHEL (WUS) as crucial components regulating the maintenance and proliferation of SAM via modulating the phytohormones auxin (IAA) and cytokinin (CTK), respectively. In this study, transcriptome analysis of the early wounding stage of Z. japonica cultivar "Zenith" was performed, and global expression pattern of genes related to the PIN1 and WUS network was analyzed. According to the Gene Ontology (GO) database classification, genes related to cell proliferation were identified in differentially expressed unigenes (DEGs) with dramatic changes. Meanwhile, there were 18 IAA and CTK-related GO terms. The Kyoto Encyclopedia of Genes and Genomes (KEGG) database classification showed that "plant hormone signal transduction" was gradually become the most abundant enrichment pathways within 6 h. Twenty-four Z. japonica genes with homology to Arabidopsis genes that are involved in PIN1 and WUS network were examined for expression. Among them, 21 genes showed dynamic changes whereas three genes did not. Those results suggesting that the key genes involved in the regeneration exhibited difference in both plants. Finally, we proposed a simple molecular mechanism of the Z. japonica organ regeneration regulated by PIN1 and WUS after wounding.