Proceedings of the XLV Italian Society of Agricultural Genetics - SIGA Annual Congress

Salsomaggiore Terme, Italy - 26/29 September, 2001

ISBN 88-900622-1-5

Poster Abstract

A NESTED-PCR TO DETECT CP GENE AND NPTII GENE IN INDUSTRIALLY PROCESSED TRANSGENIC TOMATO

LUMIA V., TOMASSOLI L., ILARDI V., BARBA M.

Istituto Sperimentale per la Patologia Vegetale, Via C.G. Bertero 22, 00156 Roma, Italy

virologia@ispave.it

transgenic tomato, industrial processing, transgene detection, nested-PCR

Labelling regulations (EC/258/97) have stimulated activities aimed at developing new and appropriate methodologies to detect the presence of Genetically Modified Organisms (GMOs) in foodstuffs. Because each transgenic crop contains its own genetic modifications, specific tests must be developed for their identification.

In our laboratory, UC82B tomato variety was genetically modified for cucumber mosaic virus (CMV) resistance using the coat protein (CP) gene and neomycin phosphotransferase (NPTII) gene as selectable marker. To monitor the presence of both transgenes in fresh and industrially processed fruits, a specific molecular test was developed.

Genomic DNA was extracted from fresh and canned tomato using a very simple, cheap and safe method that allowed to obtain a good template for PCR assay. Standard PCR allowed to detect NPTII and CP genes in fresh fruit samples only. Genomic extracts from canned tomato, routinely processed with long heat treatments, could be expected to contain traces of detectable DNA. Only nested PCR, using specific primers, was able to amplify NPTII (amplicon of 214 bp) and CP (amplicon of 276 bp) genes in industrially processed tomato.

The possibility of detecting exogenous genes during every steps of the alimentary chain is an important prerequisite to guarantee the respect of legislation regulating the agricultural use and, eventually, the commercialisation of transgenic crops and to reassure consumers.