Transgenic strawberry plants expressing a thaumatin II gene demonstrate enhanced resistance to Botrytis cinerea

A thaumatin 11 cDNA (thau II) driven by the CaMV 35S promoter was introduced into strawberry (Fragaria x ananassa) via Agrobacterium-mediated transformation. Following transformation, 19 regenerated plant lines were obtained, of which, 14 were found to possess thau II and neomycin phosphotransferase (npt H) genes, while five plants possessed only the npt H gene. In I I transformants, protein bands that reacted with a thaumatin 11 antibody were observed, while 3 plants had no detectable thaumatin II. Three transgenic lines accumulating the highest levels of thaumatin 11 protein and three control plants with npt H and uidA genes or only the npt H gene and non-transgenic plants cv. Firework were tested for resistance against gray mold (Botrytis cinerea) by infection with a conidial suspension. All transgenic lines tested expressing the thaurnatin 11 protein showed a significantly higher level of resistance compared to the control plants, as measured by necrotic lesions and sporulation of the pathogen. (c) 2005 Elsevier B.V. All rights reserved.