Lecanicillium saksenae CGMCC5329 is a useful biological control agent against plant-parasitic nematodes. The complete mitogenome sequence of L. saksenae is reported for the first time. The mitochondrial genome is 25 919 bp long with 14 typical protein-coding genes, an intronic ORF coding for a putative ribosomal protein (rps3), 2 ribosomal RNA genes and a set of 26 transfer RNA genes. The phylogeny based on 12 protein-coding genes (except the loss of other two genes in Acremonium implicatum) suggests the close phylogenetic relationship between L. saksenae and L. muscarium. Comparative analysis reveals that mitogenome of L. saksenae is 1420 bp larger than L. muscarium, mainly due to the intergenic region between cox2 and trnR. The trnC between cob and cox1 is conserved in the mitogenomes of three nematophagous fungus of Pochonia chlamydosporia, A. implicatum and L. saksenae, but absent in L. muscarium. This study may provide valuable information for further research on mitochondrial evolution of nematophagous fungus and Lecanicillium species.
An effective selection marker is necessary for genetic engineering and functional genomics research in the post-genomic era. Isaria javanica is an important entomopathogenic fungus with a broad host range and prospective biocontrol potentials. Given that no antibiotic marker is available currently in this fungus, developing an effective selection marker is necessary. In this study, by applying overlap PCR and split-marker deletion strategy, combining PEG-mediated protoplasm transformation method, the uridine auxotrophy gene (ura3) in the I. javanica genome was knocked out. Then, using this transformation system, the pH response transcription factor gene (IjpacC) was disrupted successfully. Loss of IjpacC gene results in an obvious decrease in conidial production, but little impact on mycelial growth. The virulence of the ΔIjpacC mutant on caterpillars is similar to that of the wild-type strain. RT-qPCR detection shows that expression level of an acidic-expressed S53 gene (IF1G_06234) in ΔIjpacC mutant is more significantly upregulated than in the wild-type strain during the fungal infection on caterpillars. Our results indicate that a markerless transformation system based upon complementation of uridine auxotrophy is successfully developed in I. javanica, which is useful for exploring gene function and for genetic engineering to enhance biological control potential of the fungus.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.