The effect of different treatment durations with indole-3-acetic acid (IAA)-producing endophytic Bacillus spp. on tomato 'Aicha' under saline conditions

Abstract

This study aimed to investigate the effect of indole-3-acetic acid (IAA)-producing endophytes from saline environments on survival and growth of tomato under salt stress, using different treatment times. Twenty-five endophytic bacteria were isolated from halophytes (Atriplex halimus L., Tamarix aphylla L.) issued from saline regions (Algeria). Five strains were selected based on tolerance to NaCl. A polyphasic taxonomic study was conducted. The selected strains were assigned to the Bacillus cereus group. Quantification of IAA production was done by high-performance liquid chromatography (HPLC). An in vitro test of growth promotion/protection of tomato Aicha was conducted under saline conditions (50 mM, 75 mM, 100 mM, and 125 mM), for different durations of seed biopriming (1h, 3h, and 12h). Endophytes led to a significant amelioration of salt stress in tomato Aicha at all salinity levels, depending on treatment times, indicating the necessity of optimizing this crucial factor.