Abstract
Halophilic microorganisms play a
crucial role in plant health and growth in salinity affected lands. The
objective of this study was to evaluate the haloarchaeal diversity from
the rhizosphere of halophytes and plant growth promoting abilities of
these strains. The whole genome sequences of two haloarchaeal strains,Halorubrum lacusprofundi HL1RP11 and Halobacterium
noricense NRS2HaP9, were analyzed, and genes related to plant growth
promoting traits were identified. Phylogenetic analysis showed that
archaeal strains of Halococcus, Halorubrum, Halobacterium andNatrinema were dominant in the rhizosphere of halophytes. More
than 60% of the strains were positive for phosphate solubilization and
IAA production. About 50% of strains were positive for nitrogen
fixation, while 33% were siderophore producers. More than 40% of
haloarchaeal strains showed the heavy metal resistance for Nickel,
Cadmium, Chromium and Zinc at a concentration of 5 mM. Genes involved in
plant growth promotion were identified through annotation. Gene clusters
related to secondary metabolites including phenazine, siderophore
production and terpene were also identified in this study. Our results
suggested that these haloarchaeal strains can be used as an eco-friendly
biofertilizer to improve growth and productivity in hypersaline
environment.
Keywords: Halophilic archaea; plant growth promoting traits;
osmoregulation; halophytes; Halorubrum