Title of article :
Nicotiana plumbaginifolia Leaf Extracts as an Efficient Antibacterial and a Biocontrol Agent Versus Tomato Pathogenic Bacteria
Author/Authors :
Javaheri, Golrokh Department of Microbiology - Islamic Azad University Falavarjan Branch, Isfahan, Iran , Doudi, Monir Department of Microbiology - Islamic Azad University Falavarjan Branch, Isfahan, Iran , Rahimzadeh Torabi, Ladan Department of Microbiology - Islamic Azad University Falavarjan Branch, Isfahan, Iran , Pazandeh, Mohammad Hossein Department of Pharmacology and Toxicology - School of Pharmacy - Hamadan University of Medical Sciences, Hamadan, Iran
Abstract :
Antibacterial agents derived from plants are known as suitable alternatives for synthetic pesticides because of their health
and the lack of any side effects on plants. This study aims to assess in vitro effect of water, ethanol and methanol extracts
of tobacco (Nicotiana plumbaginifolia Viv.) leaves on plant pathogenic bacteria and their effect on the control of bacterial
infection in tomato plant in the farm conditions. Also, effective compounds of the selected extract were characterized.
Water, ethanol and methanol extracts were prepared from the leaves of N. plumbaginifolia by soaking method.
Antibacterial effects of three extracts were determined by agar well diffusion method in 100, 400 and 800 mg/ml
concentrations on plant pathogenic bacteria including Xantomonas campestris PTCC1473, Pseudomonas aeruginosa
PTCC1181, Pseudomonas syringae PTCC1290, Enterobacter aerogenes PTCC1221, Clavibacter michiganensis
PTCC1399, Ralstonia solanacearum PTCC1600 and Gluconacetobacter PTCC1734. Then the effect of the extract was
analyzed on the protection of infection and some characteristics of the tomato fruit in farm conditions. For this purpose,
the tomato bushes were inoculated with the bacterium that were highly sensitive to the extracts and in order to evaluate the
effect of the extract on the tomato fruit characteristics, factors including pH, ascorbic acid content, lycopene content,
texture stiffness and antioxidant activity of tomatoes were assessed post treatment. Effective compounds of the extract
with the maximum antibacterial effect were measured using GC/MS method. Water, ethanol and methanol extracts of N.
plumbaginifolia in the minimum concentration (MIC) of 400 mg/ml were effective on the most of studied bacteria and had
the most effect on P. aeruginosa PTCC1181 with the growth inhibition zone of 22.51 mm (water extract), 19.39 mm
(ethanol extract) and 20.94 mm (methanol extract). The concentration of 800 mg/ml of the extracts was detected as
minimum bactericidal concentration (MBC). The results showed that the methanol extract of N. plumbaginifolia had the
most effect on the studied bacteria without changes in plant growth indicators. GC/MS analysis of the extract approved the
existence of several organic acids and antimicrobial compounds including benzoic acid, hydroxymethylfurfural, nicotine,
nonanoic acid, neophytadiene and plant esters. The methanol extract of N. plumbaginifolia leaves had the greatest impact
on P. aeruginosa PTCC1181 as one of the pathogens of tomato, and this extract also controlled the growth of bacteria on
the tomato plant in farm condition and this plant extract is recommended as an antimicrobial agent to control the bacterial
disease of tomato.
Keywords :
Nicotiana plumbaginifolia , Antibacterial , Biocontrol agent , Plant pathogenic bacteria , Effective compounds
Journal title :
Journal of Medicinal Plants and By-products