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: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
Project description:Metarhizium anisopliae P016 was isolated from frass material collected within wild galleries of Odontotaenius disjunctus (bessbug beetles) in the USA. Metarhizium anisopliae P287 was isolated from Odontotaenius disjunctus carcass found in the wild (USA). Both were cultured on ISP2-agar for seven days at 30C. Cultures were extracted with ethyl acetate. Reserpine was used as an internal standard.
Project description:Although most known mycoviruses are asymptomatic or reduce the virulence of their host fungi, those that confer hypervirulence to entomopathogenic fungus still need to be explored. Here, we discovered and studied a novel mycovirus in Metarhizium flavoviride, isolated from Laodelphax striatellus. Based on molecular analysis, we tentatively designated the mycovirus as Metarhizium flavoviride partitivirus 1 (MfPV1), a novel species in genus Gammapartitivirus, family Partitiviridae. MfPV1 has two double-stranded (ds) RNAs as its genome, 1,775 and 1,575 bp in size respectively, encapsidated in isometric particles. When we transfected commercial strains of M. anisopliae and M. pingshaense with MfPV1, conidiation was significantly enhanced (t-test; P-value < 0. 01), and the significantly higher mortality rates of the larvae of Plutella xylostella and Spodoptera frugiperda, two important lepidopteran pests were found in virus-transfected strains (ANOVA; P-value < 0.05). Transcriptomic analysis showed that transcript levels of pathogenesis-related genes in MfPV1-infected M. anisopliae were obviously altered, suggesting increased production of metarhizium adhesin-like protein, hydrolyzed protein and destruxin synthetase. Further studies are required to elucidate the mechanism whereby MfPV1 enhances the expression of pathogenesis-related genes and virulence of Metarhizium to lepidopteran pests. This study presents experimental evidence that the transfection of other entomopathogenic fungal species with a mycovirus can confer significant hypervirulence and provides a good example that mycoviruses could be used as synergistic agent to enhance the biocontrol activity of entomopathogenic fungi.
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: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.
2009-06-25 | GSE14846 | GEO
Project description:RNA-seq of Metarhizium anisopliae
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.