Characterization of endophytic fungi from Acer ginnala Maxim. in an artificial plantation: media effect and tissue-dependent variation.

The community of endophytic fungi associated with Acer ginnala, a common tree in northeastern China, was investigated. Four media, PDA, Czapek's, WA and Sabouraud's, were used to inoculate explants from seeds, annual twigs and perennial twigs (xylem and bark). Media strongly affected the isolated species number, but not colonization frequency (CF) or isolation frequency (IF). To investigate media effect further, a Principal Component Analysis (PCA) was done. As a result, two components accounted for 86.502% of the total variance were extracted. These two components were named as PDA-determined factor (accounted for 45.139% of the total variance) and Czapek's-determined factor (accounted for 41.363% of the total variance), respectively. This result suggested that only two media, PDA and Czapek's, could be used instead of all four media in this study without affecting the isolation results significantly. In total, ten taxa were isolated in this study. Alternaria sp., Phomopsis sp., Neurospora sp. and Phoma sp. were dominant endophytes while Pleosporales Incertae Sedis sp., Cladosporium sp., Trichoderma sp. and Epicoccum sp. were rare taxa. Different tissues/organs had different endophyte assemblages. All tissue/organ pairs had low Bray-Curtis indices (<0.3) except for bark and annual twigs (0.63). Compared to perennial twigs, annual twigs had a lower taxon number, lower isolate number, lower endophyte dominance and diversity indices. Seeds had distinct assemblage, lower similarity and similar low diversity indices to annual twigs. These results suggested that tissue type determines the endophyte assemblage while age determines the diversity

Insect anal droplets contain diverse proteins related to gut homeostasis

Abstract Background Insects share similar fundamental molecular principles with mammals in innate immunity. For modulating normal gut microbiota, insects produce phenoloxidase (PO), which is absent in all vertebrates, and reactive nitrogen species (ROS) and antimicrobial proteins (AMPs). However, reports on insect gut phagocytosis are very few. Furthermore, most previous studies measure gene expression at the transcription level. In this study, we provided proteomic evidence on gut modulation of normal microorganisms by investigating the anal droplets from a weevil, Cryptorhynchus lapathi. Results The results showed that the anal droplets contained diverse proteins related to physical barriers, epithelium renewal, pattern recognition, phenoloxidase activation, oxidative defense and phagocytosis, but AMPs were not detected. According to annotations, Scarb1, integrin βν, Dscam, spondin or Thbs2s might mediate phagocytosis. As a possible integrin βν pathway, βν activates Rho by an unknown mechanism, and Rho induces accumulation of mDia, which then promotes actin polymerization. Conclusions Our results well demonstrated that insect anal droplets can be used as materials to investigate the defense of a host to gut microorganisms and supported to the hypothesis that gut phagocytosis occurs in insects

Media effect on species isolated from <i>A. ginnala.</i>

<p>Alt: <i>Alternaria</i> sp.; Pen: <i>Penicillium</i> sp.; Neu: <i>Neurospora</i> sp.; Cla: <i>Cladosporium</i> sp.; Phoma: <i>Phoma</i> sp.; Fus: <i>Fusarium</i> sp.; Phomo: <i>Phomopsis</i> sp.; Non: Pleosporales <i>Incertae Sedis</i> sp.; Tri: <i>Trichoderma</i> sp.; Epc: <i>Epicoccum</i> sp.</p

Relative frequency of fungal endophytes from <i>A. ginnala</i>.

<p>Relative frequency (RF) means isolate frequency of a given endophyte divided by the sum of isolate frequencies of all endophytes×100.</p

α diversity indices and bootstrapping comparison between tissues.

<p>Whole tree represented by Bark + Xylem + Seed + Annual twig while perennial twig by Bark +Xylem.</p

Clustal analysis of tissues.

<p>The dendrogram was drawn by PAST with Bray-Curtis’s similarity. The numbers on the branches were the support percentage from10000 bootstraps.</p

Principal Component Analysis on the effect of media.

<p>Alt: <i>Alternaria</i> sp.; Pen: <i>Penicillium</i> sp.; Neu: <i>Neurospora</i> sp.; Cla: <i>Cladosporium</i> sp.; Phoma: <i>Phoma</i> sp.; Fus: <i>Fusarium</i> sp.; Phomo: <i>Pomopsis</i> sp.; Non: Pleosporales <i>Incertae Sedis</i> sp.; Tri: <i>Trichoderma</i> sp.; Epc: <i>Epicoccum</i> sp. Loadings over 0.7 were in bold.</p>*<p>:percentage of variance.</p>#<p>:Cumulative percentage.</p

Colonization and isolation frequency of fungal endophytes from <i>A. ginnala.</i>

<p>Colonization and isolation frequency of fungal endophytes from <i>A. ginnala.</i></p

Principal component analysis of media effect on fungal endophytes isolation.

<p>A, loading plot; B, score plot. The legends see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046785#pone-0046785-g002" target="_blank">Figure 2</a>.</p