• Journal of Plant Biotechnology
• /
• v.29 no.1
• /
• pp.7-13
• /
• 2002

Superoxide dismutase (SOD) plays an important role in cellular defense against oxidative stress in plants. We have developed transgenic tomato plants overexpressing a cassava SOD in fruits. Three transgenic tomato plants (one from cv. Pink forcer and two from cv. Koko) using a new vector system, ASOp :: . mSOD1/pBI101, harboring ascorbate oxidase promoter (ASOp) expressing dominantly in cucumber fruits, CuZnSOD cDNA (mSOD1) isolated from cultured cells of cassava, and nptll gene as a selectable marker were successfully developed. SOD specific activity (units/mg protein) in transgenic fruits of both cultivars was increased with maturation of the fruits. SOD specific activity of well-mature fruits in transgenic Pink forcer and Koko showed approximately 1.6 and 2.2 times higher than control fruits, respectively. The strength of SOD isoenzyme bands well reflected the SOD activity during the fruit maturation. These results suggested that SOD gene was properly introduced into tomato fruits in a fruit-dominant expression manner by ASO promoter.