Flooding tolerance of transgenic tomato plants expressing the bacterial enzyme ACC deaminase controlled by the 35S, rolD or PRB-1b promoter

Transgenic tomato plants Lycopersicon esculentum (Solanaceae) cv. Heinz 902 expressing the bacterial gene 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, under the transcriptional control of either two tandem 35S cauli flower mosaic virus promoters (constitutive expression), the rolD promoter from Agrobacterium rhizogenes (root specific expression) or the pathogenesi s related PRB-1b promoter from tobacco, were compared to non-transformed pl ants in their response to flooding stress. Characteristics that were studie d include shoot height, and fresh and dry weight; epinasty; ACC deaminase a ctivity; ethylene production; and leaf chlorophyll and protein content. All of the transgenic tomato plants expressing ACC deaminase showed some incre ased tolerance to flooding stress and were less subject to the deleterious effects of root hypoxia on plant growth than were non-transformed plants. P lants that included an ACC deaminase gene under the control of the rolD pro moter were protected to the greatest extent. (C) 2001 Editions scientifique s et medicales Elsevier SAS.