Background: Endophytic bacteria are ubiquitous in all plant species contributing in host plant\'s nutrient uptake
and helping the host to improve its growth.
Moringa peregrina
which is a medicinal plant, growing in arid
region of Arabia, was assessed for the presence of endophytic bacterial strains.
Results: PCR amplification and sequencing of 16S rRNA of bacterial endophytes revealed the 5 endophytic
bacteria, in which 2 strains were from
Sphingomonas sp.; 2 strains from
Bacillus sp. and 1 from
Methylobacterium
genus. Among the endophytic bacterial strains, a strain of
Bacillus subtilis
LK14 has shown
significant prospects in phosphate solubilization (clearing zone of 56.71 mm after 5 d), ACC deaminase
(448.3 ± 2.91 nM α-ketobutyrate mg
-1 h
-1) and acid phosphatase activity (8.4 ± 1.2 nM mg
-1 min
-1). The
endophytic bacteria were also assessed for their potential to produce indole-3-acetic acid (IAA). Among
isolated strains, the initial spectrophotometry analysis showed significantly higher IAA production by
Bacillus
subtilis LK14. The diurnal production of IAA was quantified using multiple reactions monitoring method in
UPLC/MS–MS. The analysis showed that LK14 produced the highest (8.7 μM) IAA on 14th d of growth. Looking
at LK14 potentials, it was applied to
Solanum lycopersicum
, where it significantly increased the shoot and root
biomass and chlorophyll (a and b) contents as compared to control plants.
Conclusion: The study concludes that using endophytic bacterial strains can be bio-prospective for plant growth
promotion, which might be an ideal strategy for improving growth of crops in marginal lands.
