oxidizing enzyme (TrpOxE), which catalyzes the first step in Nitrilase (NIT) and myrosinase are important enzymes for tryptophan-dependent auxin biosynthesis in Brassicaceae, and auxin biosynthesis in Brassicaceae, which is increased during clubroot disease. Therefore, NIT and myrosinase levels during nitrilase were enhanced after treatment with jasmonic acid (JA) and methyl jasmonate. Similarly, the amount of myrosi-club development and possible regulation mechanisms were nase mRNA was increased by JA. During clubroot disease the investigated. In addition, the occurrence of different nitrilase isoforms in Chinese cabbage has been shown. Nitrilase activity endogenous concentration of JA increased in infected roots -5 weeks after inoculation. From our results it can be was enhanced in infected roots during later stages of club development (35-42 days after inoculation). However, no concluded that: (1) de novo indole-3-acetic acid (IAA) biosyndifferences in nitrilase mRNA levels between infected and thesis plays a role for symptom development of clubroot healthy roots were found during symptom development. My-disease in Brassicaceae during later developmental stages; and(2) JA which increased during club development, may be rosinase expression was increased in clubbed roots at slightly involved in the up-regulation of three enzymes important for earlier time points (28 days after inoculation) and also at later time points during infection. The activities of tryptophan IAA synthesis.