This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Yakoby, N.
Right arrow Articles by Prusky, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Yakoby, N.
Right arrow Articles by Prusky, D.
Agricola
Right arrow Articles by Yakoby, N.
Right arrow Articles by Prusky, D.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, March 2000, p. 1026-1030, Vol. 66, No. 3
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

pH Regulation of Pectate Lyase Secretion Modulates the Attack of Colletotrichum gloeosporioides on Avocado Fruitsdagger

Nir Yakoby,1,2 Ilana Kobiler,1 Amos Dinoor,2 and Dov Prusky1,*

Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan 50250,1 and Department of Plant Pathology and Microbiology, Faculty of Agricultural Food and Environmental Quality Sciences, Hebrew University of Jerusalem, Rehovot 76100,2 Israel

Received 30 June 1999/Accepted 24 December 1999

Growth of Colletotrichum gloeosporioides in pectolytic enzyme-inducing medium (PEIM) increased the pH of the medium from 3.8 to 6.5. Pectate lyase (PL) secretion was detected when the pH reached 5.8, and the level of secretion increased up to pH 6.5. PL gene (pel) transcript production began at pH 5.0 and increased up to pH 5.7. PL secretion was never detected when the pH of the inducing medium was lower than 5.8 or when C. gloeosporioides hyphae were transferred from PL-secreting conditions at pH 6.5 to pH 3.8. This behavior differed from that of polygalacturonase (PG), where pg transcripts and protein secretion were detected at pH 5.0 and continued up to 5.7. Under in vivo conditions, the pH of unripe pericarp of freshly harvested avocado (Persea americana cv. Fuerte) fruits, resistant to C. gloeosporioides attack, was 5.2, whereas in ripe fruits, when decay symptoms were expressed, the pericarp pH had increased to 6.3. Two avocado cultivars, Ardit and Ettinger, which are resistant to C. gloeosporioides attack, had pericarp pHs of less than 5.5, which did not increase during ripening. The present results suggest that host pH regulates the secretion of PL and may affect C. gloeosporioides pathogenicity. The mechanism found in avocado may have equivalents in other postharvest pathosystems and suggests new approaches for breeding against and controlling postharvest diseases.

* Corresponding author. Mailing address: Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel. Phone: 972-3-9683610. Fax: 972-3-9683622. E-mail: prusky33{at}netvision.net.il.

dagger Contribution 407-2000 from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel.

Applied and Environmental Microbiology, March 2000, p. 1026-1030, Vol. 66, No. 3
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Kramer-Haimovich, H., Servi, E., Katan, T., Rollins, J., Okon, Y., Prusky, D. (2006). Effect of Ammonia Production by Colletotrichum gloeosporioides on pelB Activation, Pectate Lyase Secretion, and Fruit Pathogenicity. Appl. Environ. Microbiol. 72: 1034-1039 [Abstract] [Full Text]  
  • ten Have, A., Dekkers, E., Kay, J., Phylip, L. H., van Kan, J. A. L. (2004). An aspartic proteinase gene family in the filamentous fungus Botrytis cinerea contains members with novel features. Microbiology 150: 2475-2489 [Abstract] [Full Text]  
  • Drori, N., Kramer-Haimovich, H., Rollins, J., Dinoor, A., Okon, Y., Pines, O., Prusky, D. (2003). External pH and Nitrogen Source Affect Secretion of Pectate Lyase by Colletotrichum gloeosporioides. Appl. Environ. Microbiol. 69: 3258-3262 [Abstract] [Full Text]  
  • Penalva, M. A., Arst, H. N. Jr. (2002). Regulation of Gene Expression by Ambient pH in Filamentous Fungi and Yeasts. Microbiol. Mol. Biol. Rev. 66: 426-446 [Abstract] [Full Text]  
  • Rollins, J. A., Dickman, M. B. (2001). pH Signaling in Sclerotinia sclerotiorum: Identification of a pacC/RIM1 Homolog. Appl. Environ. Microbiol. 67: 75-81 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»