Dynamic rearrangement of F-actin organization triggered by host-specific plant signal is linked to morphogenesis of Aphanomyces cochlioides zoospores
Article first published online: 15 APR 2008
Copyright © 2008 Wiley-Liss, Inc.
Cell Motility and the Cytoskeleton
Volume 65, Issue 7, pages 553–562, July 2008
How to Cite
Islam, Md. T. (2008), Dynamic rearrangement of F-actin organization triggered by host-specific plant signal is linked to morphogenesis of Aphanomyces cochlioides zoospores. Cell Motil. Cytoskeleton, 65: 553–562. doi: 10.1002/cm.20281
- Issue published online: 16 JUN 2008
- Article first published online: 15 APR 2008
- Manuscript Accepted: 12 MAR 2008
- Manuscript Revised: 18 FEB 2008
- Manuscript Received: 4 OCT 2007
- Japan Society for the Promotion of Science (JSPS), Japan
- host-specific plant signal;
- actin polymerization;
Cochliophilin A (5-hydroxy-6,7-methylenedioxyflavone), a root releasing host-specific plant signal triggers chemotaxis and subsequent morphological changes in pathogenic Aphanomyces cochlioides zoospores before host penetration. The present study illustrates time-course changing patterns of cytoskeletal filamentous actin (F-actin) organization in the zoospores of A. cochlioides during rapid morphological changes (encystment and germination) after exposure to cochliophilin A. Confocal laser scanning microscopic analysis revealed that F-actin microfilaments remained concentrated at ventral groove and diffusely distributed in peripheral cytoplasm of the zoospore. These microfilaments dramatically rearranged and changed into granular F-actin plaques interconnected with fine arrays during encystment. A large patch of actin arrays accumulated at one pole of the cystospores just before germination. Then the actin plaques moved to the emerging germ tube where a distinct cap of microfilaments was seen at the tip of the emerging hypha. Zoospores treated with an inhibitor of F-actin polymerization, latrunculin B or motility halting and regeneration inducing compound nicotinamide, displayed different patterns of F-actin in both zoospores and cystospores than those obtained by the induction of cochliophilin A. Collectively, these results indicate that the host-specific plant signal cochliophilin A triggers a dynamic polymerization/depolymerization of F-actin in pathogenic A. cochlioides zoospores during early events of plant-peronosporomycete interactions. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc.