EFFECT OF 2, 4·DIACETYLPHLOROGLUCINOL PRODUCED BY Pseudomonas FLUORESCENS Q2-87 ON ULTRASTRUCTURE, PROTEINASE AND RIBONUCLEASE OF Pythium ultimum | ||||
| Journal of Agricultural Chemistry and Biotechnology | ||||
| Article 2, Volume 29, Issue 2, February 2004, Page 841-856 PDF (2.26 MB) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jacb.2004.242460 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| S. A. Youssef1; K. A. H. Tartoura1; J. M. Varqas2 | ||||
| 1Department of Agricultural Botany, Suez-Canal University, Ismailia, Egypt | ||||
| 2Department of Plant Pathology, Michigan State University, East Lansing, Mil USA 48824 | ||||
| Abstract | ||||
| Effects of exogenous application cf 2,4-diacetylphloroglucinol (2,4-DAPG) produced by the biocontrol agent Pseudotnones fluorescens Q2-87 on ultrastructure, activities of protease and ribonuclease (RNase) of Pyfhium ulfimum Trow were investigated during the time-course studied after application. Electron microscopic examination of treated Pyfhium cells relalive to the untreated ones revealed Ihat hypha I cell walls, plasma membranes, milochonoria and nuclei membranes showed disruption and degradation. Cytoplasm W(lS aggregated and cytoplasmic organelles were disorganized. Increased vacuolation was also a characteristic of the treated cells. In addition, many hyphal cells were devoid of all living components. Total soluble proteins, protease and RNase activ ties were assayed spectrophotometrically while native polyacrylamide gel of protease and RNase activities were analyzed by electrophoretically. Higher levels of protease. RNase and their specific activities and total soluble proteins were found in treated cells of Pythium compared to controls. The present results suggest that 2,4-DAPG causes disorganization, degradation and death later of P. ullimum by promoting elevated Ie leis of proteinase and RNase activities. It is concluded that 2, 4-DAPG exerted its mode of biocontrol agent action by increasing the concentration and lor activities of such hydrolytic enzymes that may affect its normal ultrastructure | ||||
| Keywords | ||||
| diacetylphloroglucinol; Protease; Pseudomonas fluorescens 02-87; Pythium ullimum; nbonuclease | ||||
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