Iron accumulation and enhanced growth in transgenic lettuce plants expressing the iron- binding protein ferritin

Abstract

We have produced transgenic lettuce plants accumulating the iron storage protein ferritin. The integration of the ferritin gene and expression levels in leaves were examined by Southern- and Western-blot analysis, respectively. It was shown that transgenic lettuce plants contained iron levels ranging from 1.2 to 1.7 times that of the control plants, however, the manganese content in transgenic lettuce plants was similar to that in the control. Enhanced growth of transgenic lettuces was observed at the early developmental stages, resulting in weights 27–42% greater than those of control plants. Transgenic lettuce had photosynthesis rates superior to those of the controls, and grew larger and faster compared with the controls during the period of 3 months from germination. These results demonstrate the possibility of producing lettuce plants with high yield, high iron content and rapid growth rate.