Submitted to: Association for Women in Science of Central Ohio
Publication Type: Abstract Only
Publication Acceptance Date: 10/12/1997
Publication Date: N/A
Technical Abstract: Flooding is one of the most serious environmental stresses that affects plant growth and productivity. The advancement of plant molecular biology allows the possibility of improving flooding tolerance in plants by genetic engineering techniques. In this study, Arabidopsis thaliana plants were transformed with the ipt gene encoding isopentenyl transferase, a rate- limiting enzyme in the cytokinin biosynthesis pathway. The chimeric gene containing the senescence specific SAG12 promoter and the ipt gene was introduced into Arabidopsis thaliana (Columbia ecotype) plants through vacuum infiltration mediated by the Agrobacterium strain GV3101. The highest transformation efficiency was obtained at 58 KPa vacuum suction. At the same suction, an increase in the duration of the infiltration from 0 to 10 min doubled the transformation efficiency. Five of the transgenic lines obtained were chosen for flooding tolerance determination. The PCR and Southern hybridization analysis confirmed that all 5 transgenic lines carr the ipt gene. The segregation of kanamycin resistance in the T2 generation indicated that these lines contained from one to multiple copies of the transgene gene. Four of the five lines grew as well as or better than wild type plants under control non-flooded condition. The transgenic lines 1, 3 and 4 were more tolerant to both root and submergence flooding than wild type plants. The results indicate that endogenously produced cytokinin can regulate senescence caused by flooding stress, thereby, increases plant tolerance to flooding. This study provides a novel mechanism to improve flooding tolerance in plants.