Effects of Agrobacterium tumefaciens-mediated transformation and tissue culture on storage lipids in Brassica napus

The variation obtained in storage fatty acids induced by the procedures of tissue culture and transformation with Agrobacterium tumefaciens was invest igated and compared in rapeseed, Brassica napus, cv. Hanna. An increased va riation in the fatty acid profiles was noted after tissue culture and trans formation compared with plants derived directly from seeds. In the second g eneration of rapeseed transformants, T-2, the content of oleic acid ranged from 39-72%, 12-31% for linoleic acid and 7-16% for linolenic acid. This co uld be compared with the oleic acid content in the T-2 generation of tissue culture-derived plants which ranged between 47-76% and in seed-derived mat erial where oleic acid ranged between 55-69%. In the T-3 generation the ran ges in transgenic seeds were decreased but still larger than in the seed de rived plants. The range in transgenic plants was 49-64% for oleic acid, 20- 28% for linoleic acid and 9-18% for linolenic acid. The most extreme indivi duals, both highest and lowest in the common fatty acids, were found in the group of transformed plants independent of generation. The total lipid con tent was also affected by the two treatments and seeds with the lowest and highest lipid content were both found among the transformed plants. In conc lusion, care should be taken to use proper controls when performing transfo rmation experiments in order to distinguish variation in the fatty acid pro files induced by the transformation procedure and tissue culture treatments from the changes due to transgenic expression.