Efficient rhizobacteria promote growth and alleviate NaCl-induced stress in the plant species Sulla carnosa

Abstract

The present work aims to characterize native bacteria from the saline rhizosphere of Sulla carnosa and to identify promising rhizobacteria isolates able to ameliorate the salt tolerance of this species. Bacteria were screened in vitro for salt tolerance capacity and plant growth promoting characteristics (PGP). Selected NaCl-tolerant bacteria showing a high PGP potential were further characterized for plant promotion effects on the growth of S. carnosa under salt stress (200 mM NaCl). Three putative salt-tolerant strains that showed multiple PGP-traits identified as Acinetobacter sp. (Br3), Pseudomonas putida (Br18) and Curtobacterium sp. (Br20) were selected for inoculation study. In a greenhouse experiment, NaCl significantly disturbed physiological parameters in non-inoculated S. carnosa. In these plants, NaCl reduced growth, increased foliar proline and malondialdehyde concomitant to Na + shoot concentrations. However, bacterial inoculation with selected PGP isolates ameliorated significantly plant growth and alleviated salt-induced physiological disturbances. Hence, as compared to non-inoculated plants, inoculation provided a significant increase in dry biomass and increased photosynthetic efficiency and chlorophyll leaf content under saline condition. Additional analysis showed that microbial inoculation also enhanced total soluble sugars content and antioxidant enzymes activities thereby preventing reactive oxygen species (ROS)-induced oxidative damage in plants. These results suggest that the inoculation of NaCl-stressed plants with selected salt-tolerant PGPR inocula exert beneficial effects on plant growth by alleviating salt-induced toxicity stress on plant growth and development.

Characterization of Plant Growth-Promoting Traits and Inoculation Effects on Triticum durum of Actinomycetes Isolates under Salt Stress Conditions

“…Several microorganisms have been reported as promoters of plant growth under saline stress [12,16,54]. Halotolerant/halophilic PGP bacteria are physiologically adapted to environmental changes and increase plant tolerance to salinity thanks to several PGP traits [52]. In the present work, we proposed the use of actinomycetes isolates to induce salt stress tolerance in wheat.…”

“…Plant inoculation with halotolerant bacteria is one the most sustainable way to cope with the numerous deleterious effects of salinity [50][51][52][53]. Several microorganisms have been reported as promoters of plant growth under saline stress [12,16,54].…”

Halo-tolerant plant growth promoting rhizobacteria for improving productivity and remediation of saline soils

“…(Br3), Pseudomonas putida (Br18) and Curtobacterium sp. (Br20) in Sulla carnosa , enhanced chlorophyll content, photosynthetic activity, total soluble sugars and antioxidant activities under saline stress [61] . With varying salt concentrations, transcription of genes responsible for osmoprotectants synthesis may express differentially in some HT-PGPR.…”

Alleviation of Salinity-Induced Oxidative Stress, Improvement in Growth, Physiology and Mineral Nutrition of Canola (Brassica napus L.) through Calcium-Fortified Composted Animal Manure

“…Among abiotic stresses, soil salinity due to accumulation of soluble salts (mainly NaCl) in arable soils is a key hazard to sustainable crop production especially in arid and semi-arid regions. Higher levels of Na + salts alter physico-chemical properties of the soils such as decreased soil porosity, water movement, and soil aeration which negatively affect uptake of essential plant nutrients and access to water by plants [3,4]. Such salt-affected soils are generally distributed throughout the world, comprising 20% of the world's cultivated land [5] and 50% of croplands are being exacerbated by varying degrees of salt accumulation [6].…”