Project description:The presence of genetic groups of the entomopathogenic fungus Metarhizium anisopliae in soil is shaped by its adaptability to specific soil and habitat types, and by soil insect populations. Although the entomopathogenic life style of this fungus is well studied, its saprophytic life style has received little consideration. While a set of functionally related genes can be commonly expressed for the adaptability of this fungus to different environments (insect cuticle, insect blood and root exudates), a different subset of genes is also expected for each environment. In order to increase the knowledge of the potential use of M. anisopliae as a rhizosphere competent organism, in this study we evaluated the genetic expression of this fungus while growing on plant root exudates in laboratory conditions during a time course.
Project description:The presence of genetic groups of the entomopathogenic fungus Metarhizium anisopliae in soil is shaped by its adaptability to specific soil and habitat types, and by soil insect populations. Although the entomopathogenic life style of this fungus is well studied, its saprophytic life style has received little consideration. While a set of functionally related genes can be commonly expressed for the adaptability of this fungus to different environments (insect cuticle, insect blood and root exudates), a different subset of genes is also expected for each environment. In order to increase the knowledge of the potential use of M. anisopliae as a rhizosphere competent organism, in this study we evaluated the genetic expression of this fungus while growing on plant root exudates in laboratory conditions during a time course. One fungal strain: Metarhizium anisopliae ARSEF 2575; Five time conditions: 0h, 1h, 4h, 8h, 12h; Five-condition experiment: Time0h vs. Time1h, Time1h vs. Time4h, Time4h vs. Time8h, Time8h vs. Time12h and Time12h vs. Time0h. Two Biological replicates: independently grown and harvested. Three replicates per array. Dye-swap was performed on replicate 2.
Project description:The entomopathogen Metarhizium anisopliae contains strains with wide host ranges and specialist strains adapted to particular hosts. Patterns of gene duplication, divergence and deletion in three generalist and three specialist strains were investigated by heterologous hybridization of genomic DNA to genes from the generalist strain ARSEF 2575. Many sequences from 2575 that are highly conserved in fungi showed rapid evolution and loss in specialist Metarhizium genomes. Some poorly hybridizing genes in specialists were functionally coordinated, including several involved in toxin biosyntheses and sugar metabolism in root exudates, indicative of reductive evolution. This suggests that specialists are loosing genes required to live in alternative hosts or as saprophytes. Several components of mobile genetic elements were also highly divergent or lost in specialists. Exceptionally, the genome of the specialist strain ARSEF 443 contained extra insertion elements that might play a role in generating evolutionary novelty. Three microarray slides were used in comparison (cDNAs are replicated in triplicate on each slide). 324 strainâ??s DNA was co-hybridized with strain ARSEF 2575 DNA in dye swapping replicate experiments and the relative hybridization efficiency (fluorescence ratio) of their DNA for strain ARSEF 2575 genes was compared. This array harbors PCR amplified fragments from the unique cDNA clones from M. anisopliae var. anisopliae ARSEF 2575 and a few genes from M. anisopliae var. acridum ARSEF 324 absent from the libraries of ARSEF 2575. In total, 1730 amplified clones were printed in triplicates on the slides. Additional background control was provided by 30 randomly distributed spots of 3Ã?SSC buffer. Printing, hybridization, and scanning of slides was as described before (Freimoser et al., 2005).
Project description:Conidial germination marks the beginning of the fungal life cycle, and understanding the genes associated with conidial germination provides insights into fungal pathogenicity and host interactions. Here, we use comparative transcriptomics to demonstrate the transcriptional similarities and differences during conidial germination and initial colony establishment in a plant pathogenic and an endophytic fungus, Fusarium graminearum and M. anisopliae, respectively. We compared the transcriptomes of F. graminearum and M. anisopliae across four stages of conidial germination: fresh conidia, polar growth, hyphal extension, and either first hyphal branching (on medium) or appressorium formation (on barley). F. graminearum exhibited a higher upregulation of CAZyme, specialized metabolite and effector genes compared to M. anisopliae during interaction with the host, particularly in the appressorium stage, reflecting its pathogenic nature. The appressorium structures formed when M. anisopliae conidia germinated on the host. The transcriptome analysis revealed that the fungus produced reduced transcript levels of CAZyme and specialized metabolite genes reflecting a less aggressive host penetration approach. The candidate genes associated with IAA synthesis were upregulated in M. anisopliae during the appressorium stage, supporting its endophytic lifestyle and suggests that the fungus uses a phytohormone based strategy to interact with plant hosts. Collectively, our findings expand the transcriptome resources and provide valuable insights into the gene networks involved in conidial germination and initiation of infection in pathogenic versus endophytic fungus.
Project description:The entomopathogen Metarhizium anisopliae contains strains with wide host ranges and specialist strains adapted to particular hosts. Patterns of gene duplication, divergence and deletion in three generalist and three specialist strains were investigated by heterologous hybridization of genomic DNA to genes from the generalist strain ARSEF 2575. Many sequences from 2575 that are highly conserved in fungi showed rapid evolution and loss in specialist Metarhizium genomes. Some poorly hybridizing genes in specialists were functionally coordinated, including several involved in toxin biosyntheses and sugar metabolism in root exudates, indicative of reductive evolution. This suggests that specialists are loosing genes required to live in alternative hosts or as saprophytes. Several components of mobile genetic elements were also highly divergent or lost in specialists. Exceptionally, the genome of the specialist strain ARSEF 443 contained extra insertion elements that might play a role in generating evolutionary novelty.
Project description:We used RNA-Seq to compare transcriptional responses of M. anisopliae and M. acridum to infection of the optically clear hind wings of adult locusts and cockroaches. It was calculated that >82% of predicted M. anisopliae genes and >88% of predicted M. acridum genes were expressed during pre-penetration growth. Germination and growth by M. anisopliae and M. acridum on either insect triggered high level expression of genes associated with translation and post-translational modifications. Between 6 to 10% of the genes that were highly expressed by M. anisopliae and M. acridum on host cuticles encoded cell wall proteins. Consistent with early host recognition events being key to establishing specificity, M. acridum but not M. anisopliae transcribed different Pth11-like GPCRs on locust and cockroach cuticles, thus differential activation of different signaling pathways.
Project description:We used RNA-Seq to compare transcriptional responses of M. anisopliae and M. acridum to infection of the optically clear hind wings of adult locusts and cockroaches. It was calculated that >82% of predicted M. anisopliae genes and >88% of predicted M. acridum genes were expressed during pre-penetration growth. Germination and growth by M. anisopliae and M. acridum on either insect triggered high level expression of genes associated with translation and post-translational modifications. Between 6 to 10% of the genes that were highly expressed by M. anisopliae and M. acridum on host cuticles encoded cell wall proteins. Consistent with early host recognition events being key to establishing specificity, M. acridum but not M. anisopliae transcribed different Pth11-like GPCRs on locust and cockroach cuticles, thus differential activation of different signaling pathways. Examination of gene differential expressions by two different Metarhizium speceis on two different insects cuticles