Salinity-resistant plant growth promoting rhizobacteria ameliorates sodium chloride stress on tomato plants

Abstract

Salinity is one of the major anthropogenic as well as environmental stresses that reduce plant growth. Results show that even after being adapted up to 6% sodium chloride (NaCl) concentration, all selected isolates were able to solubilize phosphate, and produce phytohormones, siderophores and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase enzyme. NT1 was found to exhibit the highest phosphate solubilization zones (25 mm), siderophore production (1000 mg ml (1 ) as well as ACC deaminase production (50 mMmg (1 h (1 ) potential under laboratory conditions. On the other hand, pot studies conducted on tomato plants under 2% NaCl stress proved that C4 and T15 were the best growth promoters. C4 showed 50% enhancement in root and shoot length as compared to NaCl added untreated plants as well as in absence of NaCl. C4 also enhanced salinity tolerance in plants with the lowest uptake of NaCl thereby reducing the salt stress on plants. C5 enhanced biomass production in tomato plants with increased uptake of the salts by plants, thereby reducing the salt concentration in the soil. The study thus shows that the selected isolates can be used for the plant growth promotion of plants under salinity stress.

Selection of Hyper Exopolysaccharide Producing and Cyst Forming Azotobacter Isolates for Better Survival under Stress Conditions

“…This effect may also be related to the production of EPS by Azotobacter isolate AzRDM2. Microbial EPS may both increase water holding capacity of soil and reduce water loss during desiccation (Tank and Saraf, 2010).…”

Effects of plant growth-promoting rhizobacterium (PGPR) and arbuscular mycorrhizal fungus (AMF) on antioxidant enzyme activities in salt-stressed bean (phaseolus vulgaris l.)

“…For example, Glick et al (1998) showed that under different stresses using PGPR such as Pseudomonas fluorescence can alleviate the adverse effects of stress on plant growth. It has been indicated that some PGPR are able to produce polysaccharide products, binding Na + in the root zone and hence alleviating the effects of salt stress on plant and enhancing microbial growth and activities (Tank & Saraf 2010). Many studies have demonstrated that inoculation with AM fungi improves growth of plants under salt stress (Sharifi et al 2007).…”

Rhizosphere and endophytic bacteria for induction of salt tolerance in gladiolus grown in sodic soils

“…The identification was carried out using 16S rDNA sequencing and comparing them by BLAST database. Similar process was adopted in characterization by many earlier workers (Sturz et al 2000;Kuklinsky-Sobral et al 2004;Tank & Saraf 2010). …”

“…The hydraulic conductivity in such soils used to be poor and show high impedance to root growth (Qadir & Schubert 2002). These changes in soil properties affect the rhizospheric populations, thereby affecting the productivity of the commercial crops (Tank & Saraf 2010). Gladiolus is one such commercial monocotyledonous cut flower being cultivated for years along the river basins of major rivers of many countries (Wilfret 1992).…”