Self- and nonself recognition during hyphal interactions in Rosellinia necatrix

Hyphal interactions of 10 Rosellinia necatrix isolates were analyzed. Most incompatible pairings produced broad melanized barrage lines, with a few exceptions. The variation in barrage lines revealed using light microscopy might result from distinct frequencies of different hyphal interaction types. In incompatible pairings, hyphal anastomosis was rarely observed. Activated-charcoal treatment of oatmeal agar media prevented both incompatible and compatible reactions. FUN-1 staining showed vacuole dysfunction at hyphal interaction sites, and the localization of a Lifeact-GFP mutant revealed that actin dynamics was prominent in compatible pairings. These results suggested that self/nonself recognition commonly proceeded to vacuole dysfunction and that actin dynamics played a critical role in the restoration of vacuole integrity.