Growth promotion and protection against salt stress by Pseudomonas putida Rs-198 on cotton

The strain Rs-198 isolated from alkaline soil was investigated and identified as Pseudomonas putida on the basis of its physiological and biochemical properties as well as its 16S rDNA sequence analysis. The effects of the strain Rs-198 on cotton seedling growth under salt stress were studied. The results indicated that Rs-198 could protect against salt stress and promote cotton seedling growth. After treatment with Rs-198, the germination rate and healthy stand of cotton were increased by 23.8% and 30.7%, respectively. Individual plant height, fresh weight and dry weight of cotton seedling were increased by 12.8%, 30.7% and 10.0%, respectively as compared to the control (CK). In the fields, Rs-198 also exhibited the ability to increase the cotton's germination rate and healthy stand, which were 16.0% and 22.4% higher than that of CK. Further analysis showed that Rs-198 could increase the absorption of the Mg2+, K+ and Ca2+ and decrease the uptake of the Na+ from the soil and also improve the production of endogenous indole acetic acid (IAA) content and reduce the abscisic acid (ABA) content of cotton seedling under salt stress.