Encephalartos villosus and Vigna unguiculata L. (Walp) shared symbionts contribute to V. unguiculata plant nutrition and growth in nutrient-deficient ecosystems

Abstract

Cycads are ancient plants that establish symbiotic associations with plant growth-promoting (PGP) microbes. These ancient associations are rarely contrasted with more recent associations involving PGP microbes and legumes. This study investigated if V. unguiculata growing in Encephalartos villosus acidic, and nutrient-deficient rhizosphere and surrounding soils may share similar symbionts. In addition, the biomass accumulation and plant nutrition in V. unguiculata growing in these soils was investigated. Vigna unguiculata seeds were grown in E. villosus rhizosphere and surrounding soils for 45 days. Thereafter, growth characteristics and plant nutrition were calculated. Vigna unguiculata plants grown in E. villosus rhizosphere and surrounding soils were nodulated by Paenibacillus, Bacillus, Peribacillus, Brevibacillus, Alkalihalobacillus, and Lysinibacillus species that were also identified in E. villosus coralloid roots. There were no significant differences in the total plant biomass, however, V. unguiculata plants in rhizosphere and surrounding soils invested more resources in belowground biomass. The findings of this study show that V. unguiculata and E. villosus growing in similar soil conditions may share the same symbionts promoting plant nutrient assimilation and growth.

Eragrostis curvula cultivars improve bacterial diversity, extracellular enzyme activities, and nutrition in grassland ecosystem soils

“…The Agpal cultivar growing in Jameson Park, Kaydale, and Rensburg had varying influences on the soil characteristics and extracellular enzymes, which may suggest that both plant exudates and site played a role in the selection of bacterial communities, which consequently affected the enzyme activities and soil nutrition. According to [13], environmental filters such as soil properties and abiotic factors play a role in the selection of bacterial communities. In addition, [60] reported that soil properties associated with topographic position significantly influenced the microbial composition more than the plant species in a corn-based annual cropping system and perennial switchgrass cropping system across three topographic positions.…”

“…Root secretions differ between species and cultivars [18] and influence the selection of microbial communities in rhizosphere soils, resulting in rhizosphere microbial communities unique to the plant [19]. The uniquity of rhizosphere microbial communities and their respective plants aligns with the hologenome theory, which states that the genetic material of a plant and its associated microbial communities should be regarded as a single unit, a holobiont, [20] that influences ecological fitness and adaptation to different niches [13].…”

“…Soil microorganisms and their associated enzyme activities play a significant role in the geochemical cycling of elements and their subsequent conversion into organic compounds [12]. These microorganisms and their associated enzyme activities are influenced by environmental factors such as soil properties and other abiotic factors, as per the filter theory explained by Motsomane et al [13]. Soil microbial communities are influenced by plants through root secretions that provide microbes with energy, thus supporting rhizosphere colonisation [14][15][16][17].…”