The treasure inside barley seeds: microbial diversity and plant beneficial bacteria

Abstract

Background Bacteria associated with plants can enhance the plants’ growth and resistance against phytopathogens. Today, growers aim to reduce the use of mineral fertilizers and pesticides. Since phytopathogens cause severe yield losses in crop production systems, biological alternatives gain more attention. Plant and also seed endophytes have the potential to influence the plant, especially seed-borne bacteria may express their beneficiary impact at initial plant developmental stages. In the current study, we assessed the endophytic seed microbiome of seven genetically diverse barley accessions by 16S rRNA gene amplicon sequencing and verified the in vitro plant beneficial potential of isolated seed endophytes. Furthermore, we investigated the impact of the barley genotype and its seed microbiome on the rhizosphere microbiome at an early growth stage by 16S rRNA gene amplicon sequencing. Results The plant genotype displayed a significant impact on the microbiota in both barley seed and rhizosphere. Consequently, the microbial alpha- and beta-diversity of the endophytic seed microbiome was highly influenced by the genotype. Interestingly, no correlation was observed between the endophytic seed microbiome and the single nucleotide polymorphisms of the seven genotypes. Unclassified members of Enterobacteriaceae were by far most dominant. Other abundant genera in the seed microbiome belonged to Curtobacterium, Paenibacillus, Pantoea, Sanguibacter and Saccharibacillus. Endophytes isolated from barley seeds were affiliated to dominant genera of the core seed microbiome, based on their 16S rRNA gene sequence. Most of these endophytic isolates produced in vitro plant beneficial secondary metabolites known to induce plant resistance. Conclusion Although barley accessions representing high genetic diversity displayed a genotype-dependent endophytic seed microbiome, a core seed microbiome with high relative abundances was identified. Endophytic isolates were affiliated to members of the core seed microbiome and many of them showed plant beneficial properties. We propose therefore that new breeding strategies should consider genotypes with high abundance of beneficial microbes.

Bacterial Endophytes Contribute to Rice Seedling Establishment Under Submergence

“…The analysis of functional pathway abundance for significant Pfam terms among interesting groups showed an enrichment in Arborio under submergence (Supplementary Figure 2), confirming again the unique characteristic in comparison to Lamone and the samples in air. Indeed, microbial diversity of seeds is influenced by genotype, as recently shown in barley seeds (Bziuk et al, 2021).…”

Assembly of root-associated N2O-reducing communities of annual crops is governed by selection for nosZ clade I over clade II

“…In both soils, we observed an enrichment of nosZ I OTUs classified as Acidovorax and Rhizobium in barley root-associated communities. Species within these genera can produce compounds that promote the growth of barley in soil, although the abundance of Rhizobium species associated with barley roots has been shown to be dependent on plant genotype (Bziuk et al 2021 ). Furthermore, the enrichment of nosZ II OTUs classified as Bacteroidetes in root-associated samples corresponds with previous culture- and 16S rRNA gene-based surveys on root-associated and rhizosphere communities (Johansen et al 2009 , Bulgarelli et al 2015 , Ling et al 2022 ), and may be explained by the generally copiotrophic nature attributed to organisms within this phylum.…”

Effects of Lightning on Rhizosphere Soil Properties, Bacterial Communities, and Active Components of Camellia sinensis var. assamica

“…Lightning also significantly increased the bacterial observed species index and the Shannon and Simpson indices of the Pu-erh rhizosphere soil compared with control soil samples ( P < 0.05). The diversity of soil microorganisms is closely related to plant growth, stress tolerance, and health (Ishaq, 2017 ; Bziuk et al, 2021 ; Fadiji et al, 2021 ). An increase in soil bacterial diversity may help Pu-erh tea to better cope with a changing environment, diseases, and pests and may increase biomass or quality (Wang et al, 2021 ; Yang et al, 2021 ).…”