Effect of silver nanoparticles and Bacillus cereus LPR2 on the growth of Zea mays

Abstract

The effect of Plant Growth Promoting Rhizobacteria (Bacillus sp.) and silver nanoparticles on Zea mays was evaluated. The silver nanoparticles were synthesized from Tagetes erecta (Marigold) leaf and flower extracts, whereas PGPR isolated from spinach rhizosphere. The silver nanoparticles (AgNPs) were purified using ultra centrifugation and were characterized using UV–Vis spectroscopy at gradient wavelength and also by High Resolution Transmission Electron microscopy (HRTEM). The average particles size of AgNPs was recorded approximately 60 nm. Almost all potential isolates were able to produce Indole Acetic Acid (IAA), ammonia and Hydrogen cyanide (HCN), solubilized tricalcium phosphate and inhibited the growth of Macrophomina phaseolina in vitro but the isolate LPR2 was found the best among all. On the basis of 16S rRNA gene sequence, the isolate LPR2 was characterized as Bacillus cereus LPR2. The maize seeds bacterized with LPR2 and AgNPs individually showed a significant increase in germination (87.5%) followed by LPR2 + AgNPs (75%). But the maximum growth of root and shoot of maize plant was observed in seeds coated with LPR2 followed by AgNPs and a combination of both. Bacillus cereus LPR2 and silver nanoparticles enhanced the plant growth and LPR2 strongly inhibited the growth of deleterious fungal pathogen. Therefore, LPR2 and AgNPs could be utilized as bioinoculant and growth stimulator, respectively for maize.

WITHDRAWN: Optimization of Siderophore Production by Bacillus Subtilis DR2 and its Effect on Growth of Coriandrum Sativum

“…In order to evaluate the potential of selected isolate in coriander plant, a pot experiment was conducted in a growth chamber at the Department of Botany, Patna University. The coriander seeds purchased from local market (Bakarganj, Patna, Bihar, India) were surface sterilized by exposing to 2-3 % of NaOCl followed by 70 % ethanol solution for 3 min followed by rinsing with autoclaved DW, at least for three times 10 . Sterilized seeds were soaked in autoclaved DW for 24 h at room temperature inside closed petri dishes.…”

“…Sterilized seeds were soaked in autoclaved DW for 24 h at room temperature inside closed petri dishes. Further seeds were transferred in bacterial suspension (10 8 cfu ml -1 ) at 30 º C for 6 h and sown in the pot having sterile soil (by autoclaving at 15 lbs/121 °C for 3 h) to a depth of 5 mm as a test (inoculated seeds) and control (uninoculated seeds) 10 . Sterile water was used for maintaining moisture in the pots as per requirements and observed for seed germination, root length and shoot length with respect to control and after two weeks, plants were harvested, roots were washed free of soil and shoot and root lengths were measured.…”

“…Inoculation of crop plant with different strains of PGPR increased not only the yield but also the quality of various medicinal plants as well as spice crops 7,8 . Several PGPR have been isolated all over the world with only few being commercialized including the species of Bacillus, Pseudomonas, Azobacter, Enterobacter, Azosprillum, Klebsiella, Serratia and Variovorax 9,10 . Among them, Bacillus spp.…”

Nanotechnology in plants: recent advances and challenges

“…[112][113][114] Other uses of NPs as growth stimulators include the combined formulation with bioinoculants. 115,116 Sol-gel synthesized TiO 2 NPs (50-60 nm size) co-inoculation with plant growth-promoting rhizobacteria (Bacillus thuringiensis, Paenibacillus polymyxa or Alcaligenes faecalis) improved beneficial bacterial colonization of wheat roots. 115 In another example, Ag NPs (60 nm average size) were applied in combination with the plant growth-promoting bacteria Bacillus sp.…”

“…in maize plants, resulting in a significant increase in germination and growth of root and shoot for coated seeds. 116…”