Identification and In Silico Analysis of Lectins in Gray Oyster Culinary-Medicinal Mushroom Pleurotus ostreatus (Agaricomycetes) Based on the Transcriptomes.

Lectins, one of the most important bioactive compounds, are nonimmunoglobulin proteins that can bind carbohydrates specifically. However, few reports have been published on Pleurotus ostreatus lectin at the molecular level. Hence, in this study, seven lectins were identified based on transcriptomes in four developmental stages, i.e., mycelium, primordium, young fruiting body, and mature fruiting body. The expression profiles of the lectin genes were verified by quantitative real-time PCR. Lectin2-lectin6 had the highest expression in mycelium, while lectin1 was rich in mature fruiting body, and lectin7 was in primordium. We inferred that lectin2-lectin6 may take part in cell flocculation, lectin7 was the critical gene for primordium formation, and lectinl may be involved in fruiting body maturation, respectively. By in silico analysis, all lectins were divided into three distinct groups. Lectin1-Lectin5 were about 38.5-40.7 kDa as extracellular protein and belonged to the PCL-like lectins. Lectin6 (15.4 kDa) was predicted in nucleus and belonged to fungal fruit body lectins. Lectin7 (38.5 kDa) was a member of legume-like lectins and located in the plasma membrane. This study will help us understand how lectins mediate mushroom development.