Activity of extracellular compounds of Pseudomonas sp. against Xanthomonas axonopodis in vitro and bacterial leaf blight in eucalyptus

Abstract

Bacterial leaf blight caused by Xanthomonas axonopodis is a major problem in the production of eucalyptus seedlings. The pathogen causes leaf lesions that reduce the photosynthetic area and limit plant growth. The objective of this study was to evaluate the antibiotic activity of secondary metabolic compounds of a Pseudomonas sp. against X. axonopodis, following extraction with dichloromethane and fractionation by vacuum liquid chromatography. The antibiotic activity of an ethyl acetate phase (F3 fraction) was determined by agar diffusion tests and bioautography. The minimum inhibitory concentration of F3 fraction and the action of F3 on the cell morphology of X. axonopodis was determined by scanning electron microscopy. Electron microscopy revealed changes in exopolysaccharides and morphology of treated cells. When eucalyptus seedlings were sprayed with the F3 fraction before or after inoculation with X. axonopodis in a greenhouse experiment the number of leaf lesions was respectively 93.9% and 89.7% lower than in untreated control plants. High antibiotic activity of the F3 fraction against X. axonopodis and leaf blight suggests that it has potential to control the disease in eucalyptus seedlings.

Bioactive Organocopper Compound from Pseudomonas aeruginosa Inhibits the Growth of Xanthomonas citri subsp. citri

“…In this way, the substantial control of Xcc 306 observed in a preventive treatment was likely related to mechanisms other than antibiotic activity such as SAR. The preventive effect was also observed in other studies with different species of Xanthomonas and host plants ( Lopes et al, 2012 ; Spago et al, 2014 ; Vasconcellos et al, 2014 ). Phenazine can influence growth and induce SAR in plants ( Pierson and Pierson, 2010 ), and is produced by many bacterial species.…”

“…Previous studies have shown the antibiotic effect of Pseudomonas secondary metabolites against various bacterial species ( de Oliveira et al, 2011 ; Lopes et al, 2012 ; Cardozo et al, 2013 ; Spago et al, 2014 ). In the present study, we evaluated the effect of F3d, a semi-purified fraction, on plants infected by Xcc 306, evaluating antibiotic effectiveness in the initial infection process on the leaf and the antibiotic control of Xcc 306 infecting the mesophyll tissue inside the lesions, and we determined the active pure compound present in the F3d fraction (30% OAC).…”

Chromatographic Detection of Antibacterial Antibiotics from Pseudomonas fluorescens (TNAU PF1) and Their Effect on Bacterial Wilt Pathogen Ralstonia solanacearum (KK2)

“…Previous studies have presented the antibiotic effect of Pseudomonas secondary metabolites against various bacterial pathogens [24,25,26,27]. Few studies have related antibiotics of Pseudomonas in managing the bacterial plant pathogens of tomato, however, some authors have studied the control of other diseases such as Pseudomonas sp.…”

Identifying the Compounds of the Metabolic Elicitors of Pseudomonas fluorescens N 21.4 Responsible for Their Ability to Induce Plant Resistance

“…Our results have shown that metabolic elicitor fractions extracted from the strain P. fluorescens N 21.4 were able to enhance the synthesis of isoflavones in soybean seeds between 1.2 to 3.2 times more than controls, demonstrating its potential to elicit secondary defense metabolism ( Figure 4 , Figure 6 and Figure 7 ). This capacity of elicitation was increased while the purification and concentration of the fractions (from F.1 at 100 µg·mL −1 to Fp at 1–0.1 µg·mL −1 ) progressed [ 51 ].…”