Effect of increased polyamine biosynthesis on stress responses in transgenic tobacco by introduction of human S-adenosylmethionine gene

Introduction of a human S-adenosylmethionine decarboxylase (samdc; EC 4.1.1.50) gene under the control of a constitutive promoter (CaMV35S) in tobacco (Nicotiana tabacum var. xanthi) led to increased polyamine biosynthesis. Transgenic lines with increasing spermidine and putrescine titres, especially in the conjugated forms, exhibited tolerance to salinity and drought as well as to fungal wilts caused by Verticillium dahliae and Fusarium oxysporum. This is the first report where tolerance to both abiotic and biotic stresses has been observed in transgenic plants following transfer of a polyamine biosynthesis gene. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.