Population metagenomics analysis of primary rainforest soil microbiome in South East Asia reveals a host-specific core and patterns of selection

Andrey Vaulin, Jia Jun Ngiam, Jarkko Salojärvi

Nanyang Technological University 50 Nanyang Avenue, Singapore 639798

Soil microbiome is an essential component in plant-soil feedback loop and associated with plant adaptation to different environments and their pathogen resistance. Furthermore, microbiome could possibly be one of the major contributing factors towards plant biodiversity, for example by facilitating the dominance of different plant species in primary versus secondary forest types. For these reasons, understanding the soil microbiome and its connection with the host plants is important for ecology and agriculture. 

Here we sampled and sequenced the rhizosphere and the corresponding bulk soil of two Dipterocarp species, Shorea curtisii and S. leprosula , known to harbor ectomycorrhizal assocations, and one legume species ( Koompassia malaccensis ) with arbuscular mycorrhizal as well as putative root nodule symbiosis associations. Population metagenomics analyses illustrated the high extent of genomic variation in the plant rhizosphere but still revealed a common core that depends on the species and the locally available microbiome in the bulk soil. The analyses further showed the eco-evolutionary dynamics and selection patterns imposed by plants on the soil meta-population structure, suggesting differing recruitment strategies. This work aims to facilitate understanding of the microbial component of plant-soil interactions.