Characterization of Plant-Growth Promoting Archaea Associated with the
Rhizosphere of Salsola stocksii and Atriplex a
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
and Natrinema 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.