Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/18/1998
Publication Date: N/A
Technical Abstract: The Waxy gene product, granule bound starch synthase (GBSS), is required for amylose biosynthesis. Mutations in Waxy genes result in elimination of amylose in many plant species. Our objective was to simulate a dominant loss of function mutation in hexaploid oat (Avena sativa L.) by antisense suppressing expression of the three homoeologous Waxy genes. An antisense transformation vector was constructed by placing a partial oat Waxy cDNA i reverse orientation behind the seed-specific maize adhl promoter and first intron. The nptII gene was used as a selectable marker. After microprojectile bombardment, 302 paromomycin-resistant cultures were recovered from which 82 produced fertile plants. Five T1 seeds from each transgenic line were stained with a KI/I2 solution. No seeds lacking amylose were found but some seeds from 17 lines stained lighter indicating decreased amylose levels compared with wild-type seeds. Using colorimeric and concanavalin A amylose assays we identified reduced amylose in six lines that will be further characterized.