Identification of Chitin synthase and Chitinase genes in three ontogenetic stages from Thecaphora frezii, the causal agent of peanut smut disease

Abstract

Chitin is one of the major components of the fungal cell wall. Chitin synthases participate in its biosynthesis and chitinases in its degradation. Thecaphora frezii (T. frezii) is a phytopathogenic fungus that affects peanut crops. We identified the presence of eight Chitin Synthases and four Chitinases in T. frezii, which present identities greater than 60%, when compared with their fungal counterpart Ustilago maydis. “Signature sequences” QXXEY, EDRXL and QXRRW were identified in all Chitin synthases and the DxxDxDxE sequence was seen in three Chitinases. A variable level in the mRNA expression of different enzymes was found in the three ontogenetic stages (teliospore, basidiospore, and hyphae). The in vitro chitinase activity of the three structures was evaluated, observing activity only in the protein extract of hyphae and basidiospores. These findings contribute to better understanding of the pathogen (T. frezii) biology.