Plant Growth-Promoting Pseudomonas sp. TR47 Ameliorates Pepper (Capsicum annuum L. var. conoides Mill) Growth and Tolerance to Salt Stress.

Abstract

Pepper plants are susceptible to salt stress conditions, while rhizobacteria are considered auspicious factors for boosting plant growth. In this investigation, the Tamarix gallica L. rhizospheric bacterium TR47 was assessed for its capacity to promote growth under normal and saline conditions in the greenhouse. In addition, the genetic mechanisms were investigated through genome mining. Strain TR47 demonstrated numerous growth-promoting characteristics, such as the production of siderophores, phosphate and potassium solubilization, the ability to generate 1-aminocyclopropane-1-carboxylate deaminase as well as indole-3-acetic acid production. The inoculation of pepper seedlings by strain TR47 subjected to normal and salt conditions resulted in significantly increased germination rates compared to uninoculated seeds. Furthermore, the findings demonstrated that strain TR47 exhibited greater fresh and dry biomass values in comparison to the control group, specifically during salt stress conditions. All of these characteristics may enhance plant growth and development, contribute to salt tolerance, and stress mitigation. The genome sequence of TR47 that is most likely related to Pseudomonas plecoglossicida DSM 15088 ^T consists of a single circular chromosome that is about 5.55 megabase pairs in length and has a GC content of 61.8%. By doing a comprehensive analysis of the whole-genome sequence, genes linked to the promotion of plant development were identified. Our results open up exciting possibilities for the use of TR47 as a biostimulant that may enhance pepper plants under saline conditions, sparking interest in its potential future applications.