Youssef, S., Tartoura', K., Nair, M., Varqas, J. (2004). EFFECT OF 2,4-DIACETYLPHLOROGLUCINOL PRODUCED BY Pseudomonas fluorescens Q2··87 ON P-1,3 GLUCANASE AND CELLULASE OF Pythium ultimum. Journal of Agricultural Chemistry and Biotechnology, 29(2), 825-840. doi: 10.21608/jacb.2004.242458
S. A. Youssef; K. A.أH. Tartoura'; M. Nair; J. M. Varqas. "EFFECT OF 2,4-DIACETYLPHLOROGLUCINOL PRODUCED BY Pseudomonas fluorescens Q2··87 ON P-1,3 GLUCANASE AND CELLULASE OF Pythium ultimum". Journal of Agricultural Chemistry and Biotechnology, 29, 2, 2004, 825-840. doi: 10.21608/jacb.2004.242458
Youssef, S., Tartoura', K., Nair, M., Varqas, J. (2004). 'EFFECT OF 2,4-DIACETYLPHLOROGLUCINOL PRODUCED BY Pseudomonas fluorescens Q2··87 ON P-1,3 GLUCANASE AND CELLULASE OF Pythium ultimum', Journal of Agricultural Chemistry and Biotechnology, 29(2), pp. 825-840. doi: 10.21608/jacb.2004.242458
Youssef, S., Tartoura', K., Nair, M., Varqas, J. EFFECT OF 2,4-DIACETYLPHLOROGLUCINOL PRODUCED BY Pseudomonas fluorescens Q2··87 ON P-1,3 GLUCANASE AND CELLULASE OF Pythium ultimum. Journal of Agricultural Chemistry and Biotechnology, 2004; 29(2): 825-840. doi: 10.21608/jacb.2004.242458
EFFECT OF 2,4-DIACETYLPHLOROGLUCINOL PRODUCED BY Pseudomonas fluorescens Q2··87 ON P-1,3 GLUCANASE AND CELLULASE OF Pythium ultimum
1Botany Department, Faculty of Agriculture, Suez Canal University, Ismailia, Egypt.
2Horticulture Department, Michigan S.ate University, E, Lansing, MI 48824.
3Plant Pathology Department, Michig~n State University, E. Lansing, MI48824
Abstract
In our previous study we demons' rated that the biocontrol agent, Pseudomonas fiuorescens 02-87 producing the- antibiotic 2,4-diacetylphloroglucinol (2,4·DAPG), has the ability to antagonize the phytopathogenic Pyfhium spp, by degradation of hyphal cell walls and inhibition of growth. Thin-layer chromatography (TLC)' as well as high performance liquid chromatography (HPLC) techniques were used to confirm the production of 2,4·DAPG from the biocontrol agent P. fiuorescens 02·87. Activities of polysaccharide degrading Enzymes, ~·1 ,3 and p ·1,4 glucanase (cellulase), and their relation to Pyfhium ultimum Trow cell wall degradation in relation to exogenous application of 2,4·DAPG were investigated during the first 72 h after treatment. Higher levels of ~ -qlucanases in treated P. ultimum comparing to that in control were detected. Glucanase activity reached its highest peak at 12 h; however, cellulase activity reached its highest peak at 24 h after application. Native polyacrylamide gel electrophoresis also confirmed the activities of such hydrolytic enzyme in treated Pyihium mycelia. Conclusior that bacterial cell-wall degrading enzymes origin are excluded since 2,4·DAPG isolation procedure resulted in 2,4- DAPG-free from such enzymes. The preser t results suggest that exogenous application of 2,4·DAPG to Pythium resulted in higher levels of such cell-wall degrading enzymes that participated in hyphal degradation of the oomycete Pythium