Multi omics aided small RNA profiling of wheat rhizosphere and their potential targets in contrasting soils forRhizoctonia solani-AG8 suppression

Abstract

Next-generation sequencing helps describe microbial communities in rhizosphere environments, but understanding rhizosphere-plant interactions’ synergistic effects on plant traits and health outcomes remains challenging. This study analyses rhizosphere sRNAs’ ability to manipulate host gene targets in plants grown in suppressive (SP) and non-suppressive (NSP) soils with an integrated multi omics dataset. The results showed that rhizosphere sRNAs exhibited specific compositional features that may be important for rhizosphere-plant interaction. Small RNAs, less than 30 nt in size, were predominant in both samples, with a 5-prime bias towards cytosine enrichment, suggesting potential association with wheat specific argonauts. Mapping of sRNA reads to microbial metagenomes assembled draft genomes from SP and NSP soils showed sRNA loci were differentially expressed (DE) between the soils with contrasting disease suppressive capacities. In total, 96 and 132 non redundant rhizosphere sRNAs were abundant in SP and NSP rhizosphere communities, respectively. While 55 known bacterial sRNA loci were predicted from both SP and NSP metagenomes, 127 sRNAs originated from these loci were differentially expressed. Global wheat target prediction and functional analysis from DE rhizosphere sRNAs showed both soil type specific and common pathways. Upregulated NSP sRNAs target metabolic pathways, secondary metabolite biosynthesis, MAPK signalling, while SP sRNAs target glycerophospholipid metabolism, pathways such as polycomb repressive complex, starch/sucrose metabolism, and plant-pathogen interactions were targeted by both sets of sRNAs. This is the first study showing evidence for rhizosphere sRNAs and their corresponding plant transcripts in the context of biological disease suppression in agricultural soils.ImportanceSmall RNAs (sRNAs) have gained attention in host-microbe interactions due to their diverse roles in controlling biological processes. Studies have identified numerous sRNAs with novel functions across various organisms. Echoing growing evidence of sRNAs in different plant-microbe interaction, we show an evidence of rhizosphere sRNAs regulating wheat genes in soil disease suppression context. This understanding could significantly enhance our comprehension of gene regulation in biological functions, potentially paving the way for the development of microbiome-based methods to influence host traits. Understanding the microbiome community’s mechanisms in different environments offers opportunities to modify them for agriculture, including modifying farming practices, host genetics/immunity, and synthetic communities for disease suppression.