|FONSECA-GARCIA, CITLALI - GUANAJUATO CAMPUS OF CINVESTAV|
|GARRIDO, ETZEL - GUANAJUATO CAMPUS OF CINVESTAV|
|VISEL, AXEL - JOINT GENOME INSTITUTE|
|TRINGE, SUSANNAH - JOINT GENOME INSTITUTE|
|PARTIDA-MARTINEZ, LAILA - GUANAJUATO CAMPUS OF CINVESTAV|
Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2016
Publication Date: 2/12/2016
Citation: Fonseca-Garcia, C., Coleman-Derr, D.A., Garrido, E., Visel, A., Tringe, S., Partida-Martinez, L. 2016. The Cacti microbiome: interplay between habitat-filtering and host-specificity. Frontiers in Microbiology. 7:1-16.
Interpretive Summary: Cactacea represents one of the most species-rich families of succulent plants native to arid and semi-arid ecosystems. Yet, the association cacti establish with microorganisms and the rules governing microbial assemblies remain poorly understood.We analyzed the composition, diversity and factors influencing above and below-ground prokaryotic and fungal communities associated with two sympatric and native Cacti species: Myrtillocactus geometrizans and Opuntia robusta.Phylogenetic profiling showed that the composition and assembly of microbial communities associated with Cacti was primarily influenced by the sample type. Remarkably, prokaryotic diversity was higher in the phyllosphere than in the rhizosphere of cacti, while soils exhibited the highest microbial diversity and the stem endosphere the lowest. Comparative analyses revealed that M. geometrizans, O. robusta and A. salmiana, a third sympatric CAM species, shared the same microbial symbionts in most communities, suggesting that the habitat was a strong selective force. Influence of the host genotype was mostly secondary, but played a larger role in the aerial endophytic fungal communities. These results suggest that fungi establish specific interactions with their host plant in the stem endosphere, while the rest of the microbiome may play similar functional roles across CAM plants in semi-arid environments.
Technical Abstract: The main focus of this research was to generate an holistic baseline of the associations Cacti establish with prokaryotes and fungi in the bulk and proximal soil (the soils), the rhizosphere and the phyllosphere (the episphere), as well as in the root and stem endosphere (the endosphere) through phylogenetic profiling using the 16s rRNA gene (V4) for prokaryotes and the nuclear ribosomal internal transcribed spacer region (ITS2) for Fungi. In order to also evaluate the impact of host genotype, geographic site and seasonality in the composition of microbial communities associated with Cacti, we selected two sympatric species belonging to the main subfamilies of Cactacea: Opuntia robusta (Opuntioidea) and Myrtillocactus geometrizans (Cactoideae). These species naturally occur in Central Mexico and experience two contrasting seasons based on the yearly precipitation patterns. Finally and based on our previous investigations (Desgarennes et al., 2014; Coleman-Derr et al., 2015 in press), we compare microbial communities associated with Cacti with those of Agave salmiana, a third sympatric CAM plant species, to estimate the impact of host genotype on microbial communities and infer core microbial partners of CAM plants in arid and semi-arid environments.