Evolutionary history of the necrosis- and ethylene-inducing like protein superfamily across the Dothideomycetes (Ascomycota)

• Ano de defesa: 2021
• Autor(a) principal: Dal’Sasso, Thaís Carolina da Silva
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Fungos fitopatogênicos; Evolução; Genômica; Filogenia; Genômica comparativa; Corynespora cassiicola; Fitossanidade
• Link de acesso: https://locus.ufv.br//handle/123456789/28771

Necrosis- and Ethylene-inducing peptide 1-like proteins (NLPs) form a broadly distributed superfamily involded in the early phases of plant infection and may trigger host immune responses. The majority of NLPs acts as cytotoxic proteins, inducing cell- death in eudicot plants. Dothideomycetes is a large and diverse class within the phylum Ascomycota. Corynespora cassiicola (Pleosporales) is a widespread, polyphagous plant-pathogen that causes leaf diseases on many crops. We used comparative genomic approaches and molecular phylogenetic analyses to investigate the evolutionary history of NLP across the Dothideomycetes and within C. cassiicola. Initially, we described two genomes: C. cassiicola CC_29 and C. olivacea CBS 114450. We showed that the two genome annotations differed greatly. A robust phylogenomics indicated the non-monophyly for the genus Corynespora and we suggested that the classification of C. olivacea into that genus should be revised. Subsequently, we investigate the evolution of NLPs across the Dothideomycetes. We accessed genomic resources from 33 species (five orders) with different lifestyles. The imbalanced phylogenies of NLPs suggested NLP subfamilies underwent independent evolutionary paths in the Dothideomycetes, each of which showing different signatures of ancient gene duplications and biased successive gene losses that may be associated with changes in cytotoxic activity. Subsequently, we accessed genomic resources from 44 isolates of C. cassiicola and the expression profiles of NLP- encoding genes of C. cassiicola CC_29 at the early hours of host colonization. Three NLP effector-encoding genes were maintained in the genomes of C. cassiicola and have evolved under different selective constraints. Despite highly divergent, NLP effectors maintained conserved the residues necessary to trigger plant immune responses. Nevertheless, gene expression profiles suggested that only one NLP effector gene is highly expressed at the early hours of soybean colonization by C. cassiicola. Keywords: Effector. Evolution. Phylogenomics. Comparative genomics. Corynespora cassiicola.