Freezing tolerant tobacco, transformed to accumulate osmoprotectants

Abiotic stresses are the major environmental challenges for plant growth and crop productivity. To cope with them various adaptation strategies have been developed by plants, including accumulation of osmoprotectants. Tobacco commercial cultivar was transformed to accumulate proline, fructan or glycine betaine. We used constructs harboring arabidopsis- or vigna-derived genes (AtP5Cs, VacP5Cs) for Delta(1)-pyroline-5-carboxylate synthetase production, SacB gene coding for levansucrase from Bacillus subtilis or the codA gene coding for choline oxidase from Arthrobacter globiformis. The reactions to sub-zero temperatures and osmotic stress were followed in several subsequent progenies. Stable transgenic lines have been selected. They survive freezing stress at controlled and field conditions. This is, we believe, the first report for freezing tolerance in proline and fructan transformed plants. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.