Native bacteria promote plant growth under drought stress condition without impacting the rhizomicrobiome

Abstract

Inoculation of plants with beneficial plant growth-promoting bacteria (PGPB) emerges a valuable strategy for ecosystem recovery. However, drought conditions might compromise plant-microbe interactions especially in semiarid regions. This study highlights the effect of native PGPB after 1 year inoculation on autochthonous shrubs growth and rhizosphere microbial community composition and activity under drought stress conditions. We inoculated three plant species of semiarid Mediterranean zones, Thymus vulgaris, Santolina chamaecyparissus and Lavandula dentata with a Bacillus thuringiensis strain IAM 12077 and evaluated the impact on plant biomass, plant nutrient contents, arbuscular mycorrhiza fungi (AMF) colonization, soil rhizosphere microbial activity and both the bacterial and fungal communities. Inoculation with strain IAM 12077 improved the ability of all three plants species to uptake nutrients from the soil, promoted L. dentata shoot growth (>65.8%), and doubled the AMF root colonization of S. chamaecyparissus. Inoculation did not change the rhizosphere microbial community. Moreover, changes in rhizosphere microbial activity were mainly plant species-specific and strongly associated with plant nutrients. In conclusion, the strain IAM 12077 induced positive effects on plant growth and nutrient acquisition with no impact on the rhizosphere microbiome, indicating a rhizosphere microbial community resilient to native bacteria inoculation.

Legacy of land use history determines reprogramming of plant physiology by soil microbiome

“…The role of microbial rhizosphere communities in plant growth and health is widely investigated, with most studies focusing on the effects of beneficial bacteria [18,31,49,50]. However, understanding of how agricultural land practices manipulate rhizosphere community's assembly and thus influence plant productivity is needed [51].…”

“…The performance of the rhizosphere community, e.g., nutrient acquisition, growth hormone productions, and defense against diseases, is a major determinant of the plant phenotype [25,26]. Detailed investigations of the interactions between plants and microorganisms have revealed that plants can respond to rhizosphere microbes in different ways [27][28][29][30][31]. According to a recent study, root exudatemediated changes in the rhizosphere community of peanut (Arachis hypogaea) seedlings strongly influence the physiology and further development of peanut plants [32].…”

Diversity and plant growth-promoting functions of diazotrophic/N-scavenging bacteria isolated from the soils and rhizospheres of two species of Solanum

“…Among the different tools available to increase productivity in agriculture, the use of plant growth-promoting bacteria (PGPB) has demonstrated great potential to achieve the goal of sustainability. PGPB can directly contribute to plant nutrition and can alleviate the detrimental effects caused by biotic and abiotic stresses to which field crops are subjected; PGPB can also indirectly improve soil fertility and quality by at least partially substituting for the use of chemical inputs [1][2][3][4]. Nevertheless, despite the large number of studies reporting the advantages of the use of PGPB as inoculants within commercial agricultural crops, their use as a regular agricultural practice on nonleguminous crop species is still underexplored in comparison with the amount of agricultural lands annually cultivated worldwide [5].…”

The Influence Of Treatment Variation Of Plant Promoting Bacteria In Cultivation On The Quality Of Chinese Cabbage (Brassica rapa L. Ssp.pekinensis)

“…The PGPR strain can protect from the attacks of Ralstonia solanacearum on tomatoes and Colletotrichum gloeosporioides on cayenne pepper and cucumber. Research [16], on the inoculation of plants with beneficial plant growth promoting bacteria (PGPB), raises a valuable strategy for restoring ecosystems. This study highlights the effects of native PGPB after 1 year inoculation on native shrub growth and rhizosphere composition and activity of microbial communities under drought stress conditions.…”