The effects of plant growth promoting rhizobacteria on the morphological and physiological characteristics of Haloxylon aphyllum under dust stress

Increasing concerns about the phenomenon of global warming caused by greenhouse gases have led to increased attention to the sequestration of atmospheric carbon dioxide in arid and semi-arid ecosystems. However, in the desert areas, stresses, especially dust stress, have made biological restoration operations difficult. In this research, the effect of plant growth promoting rhizobacteria on the vegetative and physiological characteristics of Haloxylon aphyllm under the influence of dust (control and 1.5 g/m2/month) was investigated. In the conditions of dust application, the Zhihengliuela halotolerans strain compared to Bacillus pumilus increased total chlorophyll (236%) and decreased ascorbic acid (75%), soluble sugar (53%), and catalase enzyme activity (65%), respectively. Under dust conditions, the B. pumilus strain performed better in terms of total phenol (52%), proline (66%), peroxidase enzyme activity (79%), and total dry biomass (108%) than the Z. halotolerans strain. The results also showed that both bacteria were able to reduce ascorbic acid, total phenol content, proline, soluble sugar, catalase and peroxidase in Haloxylon aphyllum, which showed that the use of plant growth promoting rhizobacteria can reduce free radicals and thereby prevent damage to the plant. The results of this research showed that plant growth promoting bacteria isolated from saline pasture plants can increase the seedling quality index under dust stress conditions and can help in the afforestation of Haloxylon aphyllum and the promotion of carbon dioxide sequestration in climate change conditions in arid and semi-arid ecosystems.