الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Approximately 6% of the world’ s total land area and 20% of the irrigated land are affected by salt stress. Egypt is one such country affected by salt-stress problems. This research focuses on isolation and purification of endophytic bacteria from Chickpea plants, then identify them. In this study, six species of endophytic bacteria have been isolated and identified them according to their ability of the production Indole 3-acetic acid (IAA), Root colonization, Phosphate solubilization, Nitrogen fixation, and else. Three species (Bacillus subtilis, Pseudomonas fluorescens and Bacillus cereus) showed the best results and were identified genetically using 16S rRNA sequencing. This research also focuses on the role of isolated bacteria, Bacillus subtilis and Pseudomonas fluorescens, in alleviating the harmful effects of salt stress. The results show that the irrigation of plants with different concentrations of saline water (0, 75, and 150 mM NaCl) leads to significantly decreased growth criteria, photosynthetic pigments (i.e., chl a, chl b, and carotenoids), and membrane stability index (MSI) values. Moreover, malondialdehyde (MDA), glutathione content, endogenous proline, the antioxidant defense system, 1- aminocyclopropane-1-carboxylic acid (ACC) content, ACC synthase (ACS), ACC oxidase (ACO), and Na+ content were significantly increased under NaCl-stress exposure. On the contrary, treatment with endophytic bacteria significantly increased the resistance of pea plants to salt stress by increasing the enzymatic antioxidant defenses (i.e., superoxide dismutase, catalase, peroxidase, and glutathione reductase), non-enzymatic antioxidant defenses (i.e., glutathione), osmolyte substances such as proline, and antioxidant enzyme gene expression. As a result, endophytic bacteria’ s use was significantly higher compared to control values for indole-3-acetic acid (IAA), gibberellic acid GA3 , MSI, and photosynthetic pigments. The use of endophytic bacteria significantly decreased Na+ ﴾ Summary ﴿ 92 accumulation while, at the same time, promoting K+ uptake. In conclusion, the induction of endophytic bacterium-induced salt tolerance in pea plants depends primarily on the effect of endophytic bacteria on osmoregulation, the antioxidant capacity, and ion uptake adjustment by limiting the uptake of Na+ and, alternatively, increasing the accumulation of K+ in plant tissue.