Establishment of a synthetic bacterial community and its genetic association with tropical maize

Abstract

In order to obtain a sustainable agriculture, totally or partially reducing the use of mineral fertilizers, several studies have been conducted addressing the association of plants-microorganisms with the purpose of promoting plant development. In this context, plant growth promoting bacteria (PGPB) have been isolated from the rhizospheric or endophytic region of plants and used as inoculants. However, the recent panorama of the inoculants use in Brazil has shown some inconsistency comparing in vitro and in vivo assays, sometime resulting in negative effects at the field level. The advancement of molecular sequencing technologies of DNA and RNA has demonstrated that inoculant efficiency is closely associated with microbe-microbe interactions, in which the microbiome itself buffers the effect of invasion and stability of inoculating agents in the environment. Thus, the aim of this project is to create a synthetic bacterial community, using key plant growth promotion bacterial strains, as the mainframe to modulate the taxonomy and functionality of the indigenous ecosystem microbiota, therefore creating mechanisms to favor the survival of the microbial inoculants and its association with plant, in order to improve the plant sanity. For this, a joint approach will be carried out on ecological theories, reductionist methodologies of microbial community, metagenomics and metatranscriptomics sequencing technologies. Moreover, the genetic control of SNPs (single nucleotide polymorphisms) to maize - synthetic bacterial community - PGPB will be investigated. A total of 384 tropical maize linages will be evaluated under greenhouse condition with and without inoculation. The phenotyping will be sampled by traditional and images (high resolution) methodologies. To identification of SNPs in linkage disequilibrium and characters related with plant growth promotion, molecular and phenotypic data will be evaluated by Genome-wide association studies (GWAS) (AU)