Impact of PGPR inoculation on growth and antioxidant status of wheat under saline conditions

Abstract

Two plant growth-promoting rhizobacterial (PGPR) strains, Bacillus subtilis SU47 and Arthrobacter sp. SU18, were found to tolerate 8% NaCl. Wheat co-inoculated with these two PGPR strains, and grown under different salinity regimes (2-6 dS m(-1) ), showed an increase in dry biomass, total soluble sugars and proline content. Wheat sodium content was reduced under co-inoculated conditions but not after single inoculation with either strain or in the control. The activity of antioxidant enzymes in wheat leaves decreased under salinity stress after PGPR co-inoculation, suggesting these PGPR species could be used for amelioration of stress in wheat plants. Activity of three antioxidant enzymes in wheat grown with both PGPR strains was reduced, most notably that of catalase activity at a salinity of 6 dS m(-1) , when compared with the control. The results indicate that co-inoculation with B. subtilis and Arthrobacter sp. could alleviate the adverse effects of soil salinity on wheat growth.

The Role of Soil Beneficial Bacteria in Wheat Production: A Review

“…In a follow-up study, Upadhyay et al investigated the effects of two salt-tolerant PGPR (B. subtilis and Arthobacter sp.) on wheat plants under different salinity regimes and the results obtained demonstrated alleviation of the salinity stress effects on plants treated with bacteria [97]. Similar outcome has been reported by Nia et al for Azospirillum strains on wheat plants [144].…”

“…PGPRs have been demonstrated to enhance wheat stress tolerance via osmolyte accumulation as reported in Refs. [95][96][97]. Ali et al used P. putida AKMP7 resulting in significant increase in proline levels in heat-stressed wheat plants [98].…”

“…Combined inoculation with N 2 -fixing and phosphate solubilizing bacteria were more effective than a single microorganism for providing a more balanced nutrition for plants [19,174]. There are numerous examples in wheat whereby synergistic effects of multiple PGPRs are observed [97,175,176]. Among those, notable is the combined inoculation of mixtures and biofilmed bio-inoculants (Anabaena torulosa + Pseudomonas striata and/or Anabaena torulosa + Azotobacter chroococcum) were superior over single inoculation and chemical fertilizer control in term of plant growth and nutrient uptake [177].…”

Effects of exogenously applied plant growth regulators in combination with PGPR on the physiology and root growth of chickpea (Cicer arietinum) and their role in drought tolerance

“…Khan et al (2017) reported that the combined application of PGPR lead to significant decrease in CAT, POD and SOD activities in the leaves of chickpea grown under stress conditont. Reduction in antioxidant enzymes activity by PGPR or PGR had been reported previously (Upadhyay et al 2012;Mahsa Hosseini et al 2015).…”

Influence of Exopolysaccharide-Producing Bacteria and SiO2 Nanoparticles on Proline Content and Antioxidant Enzyme Activities of Tomato Seedlings (Solanum lycopersicum L.) under Salinity Stress

“…+ silicon nanoparticles) treatment at the salinity levels of 0.3, 4, and 6 dS m -1 , S.E.N and S.E.B.N treatments at the salinity level of 8 dS m -1 could also significantly decrease the catalase activity compared to the control sample. These findings are in line with Upadhyay et al [51], who reported that bacteria could affect soil particle distribution around the roots by producing EPS and improving water availability to the considered plants and lead to decreasing the catalase activity despite saline conditions. The results of Baniaghil et al [52] indicated a significant increase in the activity of catalase enzymes in corn under salt stress and the positive effect of bacterial inoculation on reduced oxidative damage caused by salt stress, which confirms the results of the present study.…”