Lentinula edodes, popularly called Shiitake or black mushroom, is one of the most widely cultivated edible mushrooms in the world. During fruit body development essential for sexual reproduction, L. edodes displays a dramatically morphological differentiation as well as other mushroom-forming basidiomycetous fungi. To aid in effective breeding, constructing a genetic map and gene expression studies have been performed in L. edodes. Although discriminatively expressed genes in morphological changes were identified, those molecular mechanisms are not well known. Compared with the analysis of transcriptomes, protein analyses are still limited. The proteomic analysis techniques have progressed within recent years. In this study, we analyzed intracellular protein changes during fruit body development in L. edodes using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and applied expressed sequence tags (ESTs) data to tandem mass spectrometry (MS/MS) data analysis.
The fruiting body formation stage was divided into three developmental stages: vegetatively growing mycelia, primordia and fruiting bodies. Nonetheless, primordia contained slightly various proteins, quite similar patterns of protein spots were obtained in primordia and fruiting bodies. In contrast, there found many unique protein spots in vegetatively growing mycelia. Next, specifically and abundantly expressed protein spots during fruiting body formation were subjected to the subsequent MS/MS analysis. As a result of computational searches against fungal EST databases, approximately90% of spots were found to be identical to the amino acid sequences deduced from ESTs in L. edodes. In addition, several protein modifications such as phosphorylation and glycosylation were successfully detected. The obtained data helps to understand the molecular mechanism of fruiting body development in L. edodes and may provide us a new insight into the improvement of yield efficiencies for cultivations of edible mushrooms.