ACC deaminase containing endophytic bacteria ameliorate salt stress in Pisum sativum through reduced oxidative damage and induction of antioxidative defense systems

• Published in: Environmental science and pollution research international 2021-08, Vol.28 (30), p.40971-40991
• Main Authors: Sofy, Mahmoud R., Aboseidah, Akram A., Heneidak, Samia A., Ahmed, Hoda R.
• Format: Article
• Language: English
• Subjects: 1-Aminocyclopropane-1-carboxylate oxidase; 1-Aminocyclopropane-1-carboxylate synthase; Abiotic stress; Accumulation; Acetic acid; Antioxidants; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Carbon-Carbon Lyases; Carboxylic acids; Carotenoids; Catalase; Earth and Environmental Science; Ecotoxicology; Endophytes; Environment; Environmental Chemistry; Environmental Health; Environmental science; Gene expression; Gibberellic acid; Glutathione; Glutathione reductase; Indoleacetic acid; Irrigated lands; Malondialdehyde; Osmoregulation; Oxidative Stress; Peas; Peroxidase; Photosynthesis; Photosynthetic pigments; Pigments; Pisum sativum; Plant tissues; Potassium; Proline; Pseudomonas fluorescens; Reductases; Research Article; Saline water; Salinity tolerance; Salt; Salt Stress; Salt tolerance; Sodium chloride; Superoxide dismutase; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-021-13585-3

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 paper focuses on the role of isolated bacteria, such as 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 GA 3 , MSI, and photosynthetic pigments. The use of endophytic bacteria significantly decreased Na + 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.