Characterization and expression pattern of homeobox transcription factors in fruiting body development of straw mushroom Volvariella volvacea

Abstract

A number of homeobox transcription factors (TFs) play critical role in regulating developmental processes of fungi. However, studies on TFs in fruiting body development of mushroom forming species, Volvariella volvacea, are still at initial stage. Here, we report homeobox TFs in the whole-genomic sequence of V. volvacea and expression analysis of the homeobox TFs during a series of developmental stages. Homeobox TFs were identified using InterPro terms and Fungal Transcription Factor Database (FTFD) from the genome of V. volvacea and quantitative real-time PCR were used for gene expression analysis. Based on phylogenetic analysis, the homeobox TFs of V. volvacea were divided into two groups and showed close relationships with the TFs of other Basidiomycetes. Eight differentially expressed homeobox TFs were selected by digital gene expression analysis from 47 putative homeobox TFs, including five up-regulated genes in primordia and three down-regulated genes in fruiting elongation stage of V. volvacea. VvHox1, VvHox2, and VvHox3 might be participating in fruiting body elongation. It can be assumed that VvHox3 might be involved in volva development. Moreover, five TFs (VvHox4-VvHox8) might be contributing in primordia formation. Results indicated that differentially expressed homeobox TFs are significant candidates for fruiting body development study in V. volvacea.

Keywords: Chinese mushroom; Differential expression genes; Genome; Homeodomain.