Multi-Trait Wheat Rhizobacteria from Calcareous Soil with Biocontrol Activity Promote Plant Growth and Mitigate Salinity Stress

Abstract

Plant growth promoting rhizobacteria (PGPR) can be functional microbial fertilizers and/or biological control agents, contributing to an eco-spirit and safe solution for chemical replacement. Therefore, we have isolated rhizospheric arylsulfatase (ARS)-producing bacteria, belonging to Pseudomonas and Bacillus genus, from durum wheat crop grown on calcareous soil. These isolates harbouring plant growth promoting (PGP) traits were further evaluated in vitro for additional PGP traits, including indole compounds production and biocontrol activity against phytopathogens, limiting the group of multi-trait strains to eight. The selected bacterial strains were further evaluated for PGP attributes associated with biofilm formation, compatibility, salt tolerance ability and effect on plant growth. In vitro studies demonstrated that the multi-trait isolates, Bacillus (1.SG.7, 5.SG.3) and Pseudomonas (2.SG.20, 2.C.19) strains, enhanced the lateral roots abundance and shoots biomass, mitigated salinity stress, suggesting the utility of beneficial ARS-producing bacteria as potential microbial fertilizers. Furthermore, in vitro studies demonstrated that compatible combinations of multi-trait isolates, Bacillus sp. 1.SG.7 in a mixture coupled with 5.SG.3, and 2.C.19 with 5.SG.3 belonging to Bacillus and Pseudomonas, respectively, may enhance plant growth as compared to single inoculants.

Climate-Resilient Microbial Biotechnology: A Perspective on Sustainable Agriculture

“…However, researchers isolated Pseudomonas and Bacillus bacteria from wheat grain varieties planted in calcareous soil. The isolated bacteria containing plant growth-promoting (PGP) components could be investigated in vitro for additional PGP characteristics, including indole synthetic chemistry and biological control of plant pathogens, that could help promote plant growth [88]. The current review suggests that multi-trait rhizobacteria, which are active components of the arylsulphatase-producing rhizobium group, can increase, encourage, and potentiate the natural positive microbe-host association in agro-ecosystems.…”

The elusive bio-stimulatory function of Cladophialophora chaetospira SK51 to alleviate Fusarium wilt of strawberry

“…Various agricultural strategies have been implemented to mitigate the impacts of environmental stresses on crop yield. These approaches include (1) developing and producing new cultivars that are tolerant to stresses through breeding programs and genetic engineering [7]; (2) altering planting and harvesting time management [8,9]; (3) optimizing water irrigation [10,11]; and (4) developing efficient bio-fertilizers and bio-pesticides to improve plant productivity and soil health [12][13][14]. Among these, harnessing plant-microbe interactions to develop efficient bio-fertilizers for specific conditions is recognized as a crucial approach to addressing agricultural challenges.…”