Shifts in host metabolism during early stages of foliar infection and symptom development are examined.Verticillium dahliaeKleb. invaded and colonized chrysanthemum leaf tissue before symptom expression. Similar numbers of fungal propagules were recovered from non-symptomatic and symptomatic parts of a leaf lobe. No changes in relative water content, tissue permeability, RNA, and protein levels and only a slight decrease in chlorophyll level were detected within infected leaf tissue before the appearance of visible wilt. These data are discussed in relation to the possible role of senescence in theVerticilliumwilt syndrome in chrysanthemum.