Maize Endophytic Plant Growth-Promoting Bacteria Can Alleviate Plant Saline and Alkaline Stress.

Soil salinization is currently one of the main abiotic stresses that restrict plant growth. Plant endophytic bacteria can alleviate abiotic stress. The aim of the current study was to isolate, characterize, and assess the plant growth-promoting and saline and alkaline stress-alleviating traits of () isolates from maize. One endophytic bacterial isolate, named , was selected from the roots of maize grown in saline-alkali soil. The genome sequence analysis of the bacteria with a length of 5.8 Mbp includes about 700 genes that promote growth and 16 antioxidant activity genes that alleviate saline and alkaline stress. can grow below 400 mM NaHCO on the LB culture medium; The isolate displayed multiple plant growth-stimulating features, such as nitrogen fixation, produced indole-3-acetic acid (IAA), and siderophore production. This isolate had a positive effect on the resistance to salt of maize in addition to the growth. significantly promoted seed germination by enhancing seed vigor in maize whether under normal growth or NaHCO stress conditions. The seeds with NaHCO treatment exhibited higher reactive oxygen species (ROS) levels than the maize in inoculant on maize. can colonize the roots of maize. The inoculant plant increased chlorophyll in leaves, stimulated root and leaf growth, increased the number of lateral roots and root dry weight, increased the length and width of the blades, and dry weight of the blades. The application of inoculants can significantly reduce the content of malondialdehyde (MDA) and increase the activity of plant antioxidant enzymes (Catalase (CAT), Superoxide Dismutase (SOD), and Peroxidase (POD)), which may thereby improve maize resistance to saline and alkaline stress. Conclusion: isolate belongs to plant growth-promoting bacteria by having high nitrogen concentration, indoleacetic acid (IAA), and siderophore, and reducing the content of ROS through the antioxidant system to alleviate salt alkali stress. This study presents the potential application of as a biological inoculant to promote plant growth and mitigate the saline and alkaline effects of maize and other crops.