Enhanced formation of flowers and seeds in salt-stressed Arabidopsis after genetic engineering of the accumulation of glycinebetaine

Abstract

Transformation with the codA gene for choline oxidase allows plants to synthesize glycinebetaine (GB) and enhances their ability to tolerate various kinds of stress. We examined the tolerance of transformed plants to salt stress at the reproductive stage, which is the stage at which plants are most sensitive to stress. Exposure of wild-type plants to salt treatment resulted in the abortion of floral buds and a decrease in the size and number of siliques. Microscopic examination of floral structures revealed that salt stress affected the development of all the flower organs. These effects were significantly reduced in transgenic plants. We postulated that the enhanced tolerance of the transgenic plants was a result of an accumulation of GB in the reproductive organs and in the shoot apices. We also observed an increase in the number of flowers produced in transgenic plants compared to wild-type plants, under both control and salt-stressed conditions.