XVI International Botanical Congess

Trehalose phosphate synthase gene which product is a key enzyme in trehalose biosynthesis was isolated from osmophillic yeast Zygosaccharomyces rouxii and subcloned into pHG644 binary vector for tobacco nuclear transformation under the control of CaMV 35S promoter and pSBL-TPS for chloroplast transformation. Several nuclear transformants and one chloroplast transformant were obtained. Both chloroplast and nuclear transformants overexpressing TPS resulted in severe retarded plant growth, and nuclear transformant did not produce mature seed even if it flowered. Plants grown from T1 seed of chloroplast transformant showed resistance to osmotic stress compared to control on growth media containing PEG.