|Huynh, Le Nguyen|
Submitted to: Mid Atlantic Plant Molecular Biology Society Conference
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2003
Publication Date: 8/7/2003
Citation: VANTOAI, T.T., LIU, F., MOY, L., HUYNH, L., BANOWETZ, G., QUACKENBUSH, J. 2003. INSIGHTS INTO FLOODING TOLERANCE OF SAG12:IPT ARABIDOPSIS PLANTS THROUGH TRANSCIPTOME ANALYSES. Mid Atlantic Plant Molecular Biology Society Conference. p. 22. Interpretive Summary:
Technical Abstract: Isopentenyl transferase, the rate limiting enzyme in the cytokinin biosynthesis pathway, is encoded by the ipt gene isolated from Agrobacterium tumefaciens. Transgenic Arabidopsis plants that express ipt under the control of the senescence-specific SAG12 promoter show normal growth but exhibit a 7- to 10- day delay in plant senescence. The SAG12:ipt plants remain greener and produce more biomass and seeds than wild-type (WT) plants under waterlogging and submergence stress. In this study, the temporal patterns of ipt expression and cytokinin accumulation were determined at specific time points during the 0 to 5 day flooding period. Whole genome expression profiling using DNA microarrays representing 27,000+ genes encoded in the Arabidopsis nuclear, chloroplast and mitochondrial genomes was conducted at the same time points. Under non-stressed conditions, the SAG12:ipt plants produce similar level of cytokinin as WT plants, but after 5 d of waterlogging, the transgenic plants accumulated tenfold more ipt transcripts and two to threefold more cytokinin. After 5 d of complete submergence, ipt transcript accumulation increased twofold in transgenic plants although no difference in cytokinin accumulation was detected between WT and transgenic plants.