Calmodulin M phylogeny, mating type and alkaloid gene profiles reveal a high diversity of asexual Epichloë species in Argentina

MC CARGO, P.; CHARLTON N.; FLOREA S.,; SCHARDL, C.L.; IANNONE, L.J.

Melbourne

Congreso; 9th ISFEG and 1 ISPM; 2015

AGRIBIO-La Trobe University

Asexual epichloae have been detected in XX host species from Argentina. Phylogenetic analyses of sequences of nuclear genes allowed describing four species, the Epichloë typhina x E. festucae hybrids, Epichloë pampeana associated to Bromus auleticus and E. tembladerae associated to most of the host species studie; E. cabralii (E. typhina x E. amarillans - E. baconii ancestor) in Phleum alpinum and the non hybrid E. typhina subsp. poae var. aonikenkana in some populations of the Bromus setifolius species complex. Here we study the diversity of endophytes from XX hosts from Argentina performing phylogenetic studies of calmodulin M (calM) and indole di-terpene biosynthesis (idtG ) gene sequences. We also screened of the presence of some alkaloid biosynthesis gene (perA, lolC, dmaW, and idt and mating type genes. With the exception of E. typhina subsp. poae var aonikenkana, all of the isolates presented two copies for calM gene. Although calM phylogenetic trees were not totally resolved, eight lineages could be established through the combination of the clades established in the phylogeny of each copy: the previously described species, while the other four were new E. typhina x E. festucae hybrids: two of them (named A and B) were associated with Bromus auleticus, lineage C was associated with Festuca superba, Poa lanigera and Bromus brachyanthera and lineage D was associated with B. brachyanthera, all of them. In addition E. typhina subsp. poae var. aonikenkana was discovered infecting Festuca hieronymi. All of the lineages presented perA gen but lolC was only detected in E. cabralii, E. pampeana and lineage A. EAS gene dmaW was only detected in lineage B and IDT genes were not detected in E. pampeana, E. cabralii and lineaged A whereas E. tembladerae, E. typhina subsp. poae var aonikenkana, lineage B and lineage C presented IDT genes. IDT genes-profile revealed a high diversity due to variability in gene presence among the different lineages showing intraspecific variability in E. tembladerae.Mating type genes and IDT genes phylogeny suggested two or three independent origins for the E. typhina x E. festucae hybrids. Epichloë pampeana and genotype A had mating type AB indicating that both ancestors presented different mating type, whereas E. tembladerae and lineages B, C and D presented mating type AA suggesting that the E. typhina subsp. poae and E. festucae strains involved in the hybridization event were both mating type A. All of the mating type AA lineages were IDT+ with only one copy of each IDT gene. However they differed in the ancestral origin of the IDT genes, whereas E. tembladerae has E. festucae?s IDT genes, genotypes B, C and D had E. typhina?s derived genes.