The complete ORF of MaAC encoded a predicted Compound C in vivo protein this website of 2,169 amino acids (aa) with a molecular mass of 542.0 kDa. An analysis using SignalP
suggested that the N-terminal sequence of MaAC had no signal peptide. The predicted protein had a high similarity to the adenylate cyclase gene (ACY) of Metarhizium anisopliae (98% identity, EFY97222.1), the adenylate cyclase gene of Cordyceps militaris (98% identity, EGX90508.1), MAC1 of M. oryzae (96% identity, AAC34139.1) and SAC1 of S. sclerotiorum (95% identity, ABF71879.1). A fungal phylogenetic tree was established using MEGA 4.0 (Figure 1). MaAC was most similar to the sequence of the entomopathogenic fungus M. anisopliae, belonging to the Sordariomycetes. All species were members of the subdivision Pezizomycotina
in the division Ascomycota. Figure Selleckchem GW4869 1 Neighbor-joining tree inferred from MaAC protein sequence alignment. Numbers on the nodes represent the results of bootstrap analyses (1,000 replicates), using the neighbor-joining method. Fungal species: M. acridum (JQ358775), Metarhizium anisopliae (EFY97222.1), Cordyceps militaris (EGX90508.1), Gibberella zeae (XP_381410.1), Gibberella intermedia (AAY79378.1), Colletotrichum lagenarium (BAD04045.1), Magnaporthe oryzae (AAC34139.1), Grosmannia clavigera (EFW99531.1), Chaetomium globosum (XP_001221049.1), Neurospora crassa (BAA00755.1), Neurospora tetrasperma (EGZ77248.1), Blumeria graminis (CAC19663.1), Sclerotinia sclerotiorum (ABF71879.1), Botryotinia fuckeliana (CAB77164.1), Paracoccidioides
brasiliensis (AAS01025.1), Ajellomyces dermatitidis (XP_002624019.1), Coccidioides posadasii (EFW21958.1), Penicillium marneffei (XP_002146654.1), Aspergillus niger (XP_001394156.2), Spathaspora passalidarum (EGW29847.1), Aspergillus fumigates (CAC81748.1), Aspergillus clavatus (XP_001268121.1), Spathaspora passalidarum (EGW29847.1). Knocked-down MaAC transcription by RNAi We conducted an RNA interference (RNAi) strategy to study the function of MaAC. Phosphinothricin-resistant transformants of M. acridum were generated by transformation with the vector pK2-Pb-MaAC-RNAi Ketotifen (Figure 2A). To investigate the efficiency of RNAi, the wild type and RNAi mutants of MaAC were analyzed by quantitative RT-PCR. Compared to the wild type, MaAC transcription in the RNAi mutants was downregulated by 66.0%, 43.5%, 23.1%, 36.2% and 38.8%, respectively (Figure 2B). These results demonstrated that the transcription of MaAC was efficiently knocked down. Figure 2 Construction and quantitative RT-PCR analysis of the AC-RNAi mutant. A. Maps of pPK2-Pb-MaAC-RNAi, the silencing vector for MaAC. PgpdA: promoter of gpd from A. nidulans; bar: herbicide resistance gene; TtrpC: terminator of trpC from A. nidulans; AC: partial sequence of the adenylate cyclase element gene in M. acridum. B. Relative expression of MaAC in the wild type (calibrated as 100%) and three RNAi strains. Error bars denote standard deviations of three trials.