Bacillus safensis strain YA8 linked with Opuntia ficus-indica leaves: Molecular identification, and impact on Cucumis sativus growth under salt stress Entophytic bacteria improves Plant growth in salt stress

Abstract

The aim of this study was to identify the bacterial endophytic strain linked to the leaves of the Opuntia ficus-indica plant that grows close to the Makkah Desert in the Kingdom of Saudi Arabia. Bacterial endophytes can considerably penetrate plant leaves. For the sake of plant survival, living in demanding (salinity and drought) ecosystems seems to be especially crucial. Several endophytic bacteria were isolated from leaves of Opuntia ficus-indica. For phylogenetic analysis the 16s rRNA region was sequenced. To study phylogeny, the ten species were divided into three different operational taxonomic groups and classified as OTUs. Four isolates were examined, all having plant growth-promoting abilities among them. Bacillus safensis strain YA8 was assigned as one of the isolates that stood out for their ability to stimulate plant growth by producing the IAA enzyme. Bacillus safensis strains indicate effective activity against S. aureus (9 mm), S. scabiei (12 mm), and E. carotovora (19 mm) zone inhibition. The study found that the creation of IAA has increased the length of the roots and shoots and helped in biomass production as well as total chlorophyll contents in different NaCl concentrations (100 mM, 150 mM, and 200 mM). Although Opuntia ficus-indica plants have an unusually wide variety of endophytic associations, the bacillus genera alone, which are frequently reported as endophytes in plant leaves, predominated in the bacterial community. This study demonstrates that a variety of endophytic bacteria are present in Opuntia ficus-indica leaf tissue. These bacterial endophytes' potential contributions to plant hosts' ability to withstand harsh situations are examined.