Only Cas1 from isolate CCP was expressed in RRIM 600 and FDR 5788 cultivars (Fig. 5). No Cas3 or 4 transcripts were detected post-inoculation at any time point for any of the endophytic isolates. The Cas1 expression profile in RRIM 600 was as expected based on previous analyses (Déon et al. 2012), with a transient peak of expression
at 2 dpi. In FDR 5788, no GSK126 peak of expression was observed and the Cas1 relative expression remained similarly low at all time points. Fig. 5 Real-time PCR analysis of Cas gene expression 1, 2, 5 and 9 days post-inoculation onto the (a) RRIM 600 cultivar and (b) FDR 5788 cultivar. Data presented are means ± the standard error of three independent replicates. Values followed by the same letter were not significantly different BYL719 purchase according to Tukey’s HSD test (P < 0.05) Discussion Diversity of the fungal endophytes in Hevea brasiliensis There are still only a few studies investigating endophytic fungi in Hevea brasiliensis. The largest analysis was
performed on wild Luminespib rubber trees from Peru and compared the diversity of endophytic fungi in leaves and sapwood (Gazis and Chaverri 2010). A second study was conducted on cultivated rubber trees from rubber plantations in Bahia, Brazil with the objective of identifying antagonists to Microcyclus ulei, another fungal pathogen of the rubber tree (Rocha et al. 2011). In our study, as in the study by Rocha et al., all of the isolates identified were Ascomycetes. Gazis and Chaverri (2010) found that Ascomycetes were dominant (97 % of the isolates), but Zygomycota and Basidiomycota were also represented (2 % and 1 %, respectively), in agreement with the hypothesis that biodiversity is more important in the wild than in plantations. However, the identity and prevalence of the various isolated species varied among these three studies. In our study, the dominant genera were Colletotrichum (49 %), Phomopsis (15 %) and Nigrospora (13 %). Among these genera, only Colletotrichum and
Phomopsis were found in all three studies. In the populations isolated from wild rubber trees from Peru (Gazis and Chaverri 2010), Pestalotiopsis, Trichoderma and Penicillium genera predominated (23 %, 22 % TCL and 18 % of all isolates). Surprisingly, none of these genera were isolated in the course of this study or by Rocha et al. (2011). This could be explained by the difference in geographical origin or cultivation history of the rubber trees. Gazis and Chaverri (2010) sampled wild rubber trees from the most biodiverse and undisturbed area of the world (Gazis and Chaverri 2010), while our study and Rocha et al. (2011) sampled rubber trees from plantations where biodiversity is clearly less important than in the forest. It should be underlined that Rocha et al.