Studies on the response of carrot cells to a Sclerotinia sclerotiorum elicitor: induction of the expression of an extracellular glycoprotein mRNA.

A heat-released elicitor (HRE) obtained from Sclerotinia sclerotiorum mycelium induced a transient increase in the activity of phenylalanine-ammonia lyase (PAL) in a carrot cell culture. Differential display reactions carried out on total RNA extracted from cells exposed for 7 h to the HRE revealed a complex cell response involving the induction and repression of several mRNAs. One of these elicitor-induced mRNAs encodes a 42.6-kDa protein. Northern (RNA) blot analysis and reverse-transcription polymerase chain reaction studies showed that noninduced cells have a basal expression of the 42.6-kDa protein mRNA that was stimulated five- to 10-fold by treatment with the elicitor.