@article{JRC38141, address = {OXFORD (ENGLAND)}, year = {2008}, author = {Schmidt-Heydt M and Richter W and Michulec M and Buttinger G and Geisen R}, abstract = {Based on the sequence of ochratoxin A polyketide synthase gene (otapks PV) a conventional PCR to detect and identify P. verrucosum in wheat has been developed. This PCR is specific for P. verrucosum. It only shows cross reactivity with P. nordicum, the other ochratoxin A producing Penicillium species. This PCR system could be used to detect P. verrucosum in contaminated wheat, if the cell number was above 10³ cfu/ml. In a further approach a Real Time PCR system has been applied to determine the growth kinetics of P. verrucosum in wheat. The data obtained by Real Time PCR correlated well with the data obtained by the plate count technique. For this purpose the DNA was isolated directly from contaminated wheat without further enrichment step. Again at cell numbers hogher than about 10³ cfu/ml the Real Time PCR gave detectable results. In a reverse transcriptase Real Time PCR, the expression of the otapksPV gene in wheat was detected. Expression starts about 22 days after inoculation and storage at room temperature. Reasonable amounts of ochratoxin A however could only be detected starting at day 30. The early induction of the ochratoxin A biosynthesis genes in wheat was confirmed by microarray analysis. A full induction of the ochratoxin A related genes could be detected at day 22, whereas non-contaminated wheat showed no microarray signal at all. }, title = {Comprehensive Molecular System to study Presence, Growth and Ochratoxin A Biosynthesis of Penicillium verrucosum in Wheat}, type = {}, url = {http://www.informaworld.com}, volume = {25}, number = {8}, journal = {FOOD ADDITIVES AND CONTAMINANTS}, pages = {989-996}, issn = {0265-203X}, publisher = {TAYLOR & FRANCIS LTD}, doi = {10.1080/02652030801961305}