Indole acetic acid and ACC deaminase fromendophytic bacteria improves the growth of Solanum lycopersicum

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.

Ameliorative effect and potential mechanism of Ermiao san on adjuvant-induced arthritis in rats

Purpose: To investigate the effect and mechanism of action of Ermiao san (EMS), a traditional Chinese herbal formula, on inflammation development and production of inflammatory mediators in adjuvantinduced arthritis (AIA). Methods: AIA was induced by injection of 0.1 ml Freund’s complete adjuvant (FCA, 10 mg/ml) in the left hind footpad of the rats. AIA rats were intragastricly treated with 0.5, 1, 2 g/kg EMS or 0.1 g/kg methotrexate from day 7 to 28 after FCA challenge. Foot volume and histological score were measured. Osteoclast number was calculated by tartrate-resistant acid phosphatase (TRAP) staining assay. Levels of prostaglandin (PG) E2, tumor necrosis factor (TNF) -α and interleukin (IL)-1β in serum were determined by enzyme-linked immunosorbent assay (ELISA) while the level of nitric oxide (NO) in serum was analyzed by Griess reaction method. Results: Foot volume, histological score, osteoclast number and serum levels of TNF-α, IL-1β, PGE2 and NO were all increased in AIA group rats on day 28 after FCA challenge (all p < 0.01) compared with control. EMS (1 and 2 g/kg) significantly decreased the foot volume of AIA rats by 10 % (p < 0.05) and 19 % (p < 0.01), respectively, compared with AIA group. Furthermore, 1 and 2 g/kg EMS significantly reduced histological score by about 28 % (p < 0.05) and 46 % (p < 0.01), respectively, as well as osteoclast number by 12 % (p < 0.05) and 15 % (p < 0.05), respectively, compared with AIA group. In addition, 1 and 2 g/kg EMS significantly decreased the serum levels of TNF-α about 23 % (p < 0.05) and 43 % (p < 0.01), IL-1β by15 % (p < 0.05) and 26 % (p < 0.01), NO 13 % (p < 0.05) and 26 % (p < 0.01) as well as PGE2 by 11 % (p < 0.05) and 15 % (p < 0.01), respectively, compared with AIA group. Conclusion: These results suggest that EMS probably alleviates arthritis development and joint destruction by decreasing the production of inflammatory mediators in AIA rats.