Abstract
The microbial community of complex association of plant is vital for the health of the plant. Plants able to form the microbiome of their rhizosphere as the new advanced research in plant-microbe interaction is revealed. Also, the recent research suggested the fact that the microbial communities help some desert plants in drought tolerance by microbial water production. This study focused on the characterization of rhizosphere bacteria of desert plant Calotropis procera to investigate the relationship between this plant and its rhizosphere microbial communities. The study was achieved via deep sequencing of the V3-V4 regions (∼415 bp) of bacterial 16S rRNA. A total of 2173 operational taxonomic units (OTUs) were assigned sequence tags across samples with at least 97% similarity. A total of 24 OUT is selected with cutoff 1000 abundance. The results showed that the most popular phyla are Acidobacteria (two genera), Actinobacteria (fourteen genera), Bacteroidetes (one genus), Proteobacteria (6 genera), and Firmicutes (nine genera). Highly abundant genera included Ammoniphilus, Bacillus, Iamia (which reported for a first time in soil), Microvirga, Nocardia, Streptomyces, Defluviicoccus, Mycobacterium, Nocardioides, Sphingomonas, Bryobacter, Ammoniphilus, Stenotrophobacter, Arthrobacter, Actinomadura, and Marmoricola. At the species level, high abundance of Nocardia cyriacigeorgica, Rhodospirillales bacterium WX36, and Arthrobacter crystallopoietes in C. procera rhizosphere. These results show that there are at least 20 unknown species (identified at genus or family levels) in C. procera rhizosphere which are not found in rhizosphere free plants.