Isolation and identification of endophytic bacteria from Mentha longifolia and their application for the enhancement of wheat growth under salt conditions

Abstract

Various plant growth promoting endophytic bacteria (PGPE) have been shown in numerous publications to help their host plants in adapting to a variety of biotic and abiotic challenges, this is advantageous when attempting to strengthen protection towards biotic and abiotic stressors and increase plants productivity. pesticides and fertilizers made of chemicals have been replaced by endophytic bacteria. The purpose of this work was to isolate endophytic bacteria from Mentha longifolia and screen the bacterial processes involved in promoting plant growth. Three of the ten isolates were selected for further analysis based on attributes such as nitrogen fixation, phosphate-solubilizing activities, production of indole-3-acetic acid and ammonia, and salt tolerance. The 16S rRNA gene sequencing analysis revealed that these isolates belong to Streptomyces mutabilis, Priestia megaterium, and Bacillus pumilus. The plant-promoting properties were evaluated and their effects on the early stage and vegetative growth of wheat (Triticum aestivum L.) were observed using the paper towel method and pot test. When compared to the non-inoculated control, the PGPE treatment frequently showed a significant increase in the germination percentage, root and shoot length, and other growth parameters of wheat. These effects were noticeable on plant growth under salt stress. Based on these findings, it is possible to use B. pumilus, P. megaterium, and S. mutabilis as biofertilizers to help T. aestivum cope with salt stress.