The Arabidopsis sugar-insensitive2 (sis2) mutant displays a novel combination of altered sugar and phytohormone responses
Sommerlad, Lydia Christine
Gibson, Susan I.
Master of Arts
Sugars are thought to affect many plant developmental processes; however, little is known about the mechanisms involved. Ultimately, gaining an understanding of these mechanisms may help improve crop yield. As a first step, this work characterized the Arabidopsis sugar-insensitive2 ( sis2) mutant. Previous work shows that sis2, unlike wild type, develops a substantial shoot system on high concentrations of glucose, sucrose, and sorbitol; in addition, the sis2 mutant germinates on paclobutrazol, a gibberellin biosynthesis inhibitor. This thesis demonstrates that sis2 exhibits resistance to the effects of gibberellin and brassinosteroid biosynthesis inhibitors during germination, but not during later developmental stages. In addition, sis2 is resistant to the combined inhibitory effects of glucose and paclobutrazol on germination. These results suggest a novel connection between phytohormone and sugar response pathways.