Rhizobium Inoculation Drives the Shifting of Rhizosphere Fungal Community in a Host Genotype Dependent Manner

Abstract

Rhizosphere microorganisms play important roles in plant health and nutrition, and interactions among plants and microorganisms are important for establishment of root microbiomes. As yet, plant-microbe and microbe-microbe interactions in the rhizosphere remain largely mysterious. In this study, rhizosphere fungal community structure was first studied in a field experiment with two soybean cultivars contrasting in nodulation grown in two rhizobium inoculation treatments. Following this, recombinant inbred lines (RILs) contrasting in markers across three QTLs for biological nitrogen fixation (BNF) were evaluated for effects of genotype and rhizobium inoculation to the rhizosphere fungal community as assessed using ITS1 amplicon sequencing. The soybean plants tested herein not only hosted rhizosphere fungal communities that were distinct from bulk soils, but also specifically recruited and enriched Cladosporium from bulk soils. The resulting rhizosphere fungal communities varied among soybean genotypes, as well as, between rhizobium inoculation treatments. Besides, Cladosporium were mostly enriched in the rhizospheres of soybean genotypes carrying two or three favorable BNF QTLs, suggesting a close association between soybean traits associated with nodulation and those affecting the rhizosphere fungal community. This inference was bolstered by the observation that introduction of exogenous rhizobia significantly altered rhizosphere fungal communities to the point that these communities could be distinguished based on the combination of soybean genotype and whether exogenous rhizobia was applied. Interestingly, grouping of host plants by BNF QTLs also distinguished fungal community responses to rhizobium inoculation. Taken together, these results reveal that complex crosskingdom interactions exist among host plants, symbiotic N 2 fixing bacteria and fungal communities in the soybean rhizosphere.

Rhizobium-Linked Nutritional and Phytochemical Changes Under Multitrophic Functional Contexts in Sustainable Food Systems

“…Organic carbon and nitrogen produced by the photosynthesis-nitrogen fixation machinery of legumes and rhizobia supports consumers at various trophic levels. Consumers are affected by compatible relationships between host plants and Rhizobium species (Dean et al, 2014;Naluyange et al, 2014Naluyange et al, , 2016Pulido et al, 2019;Karoney et al, 2020;Xu et al, 2020). Consumers are also affected by antagonisms arising from incompatible relationship between host plants and rhizobium species (Gourion et al, 2015;Clúa et al, 2018; Modi et al, 1985;Guerinot et al, 1990;Deshwal et al, 2003a Rhizobium Rioux et al, 1986;Dilworth et al, 1998;Deshwal et al, 2003a Benezech et al, 2020a).…”

Streptomyces sp. strain TOR3209: a rhizosphere bacterium promoting growth of tomato by affecting the rhizosphere microbial community

“…Although many studies have demonstrated that PGPR play a key role in affecting the biological characteristics of plants through changes in composition and structure of rhizobiome, most of the studies have focused on only one time point and one influencing factors, and the regulation of rhizomicrobiome by a certain microorganism in the entire life cycle of plant growth has been rarely studied 7 . Currently, non-cultivation methods with high-throughput sequencing technology have been widely applied in studies on rhizomicrobiome that overcome the limits of microbial culture and isolation technology.…”

“…In rhizosphere, the bacteria so called plant growth promoting rhizobacteria (PGPR) 5 could promote plant growth by various mechanisms, such as inhibiting phytopathogens, improving plant nutrient supply, producing phytohormones, and modifying physicochemical properties of soil 6 . On the other hand, PGPR also can affect the composition of microbial communities in the rhizosphere (rhizomicrobiome) of associated plants, which in turn affect the health of the entire soil microbiome 7,8 and affect the growth of plants. Zhang et al 9 identified a consortium of three PGPR strains (Bacillus cereus AR156, Bacillus subtilis SM21, and Serratia sp.…”

Integral Characterization of the 16S rRNA Gene of Non-sporulating Bacteria and Its Action Against Anticarsia gemmatalis Hübner (Lepidoptera: Erebidae)

“…The microbiota of vegetables includes fungi, protozoa and bacteria that can negatively influence their crop production. Beneficial relationships can also happen, such as the symbiosis of several species of microorganisms in the root of leguminous plants (Xu et al, 2020).…”