EAF1 regulates vegetative-phase change and flowering time in Arabidopsis

We have identified a new locus that regulates vegetative phase change and f lowering time in Arabidopsis. An early-flowering mutant, eaf1 (early flower ing 1) was isolated and characterized, eaf1 plants flowered earlier than th e wild type under either short-day or long-day conditions, and showed a red uction in the juvenile and adult vegetative phases. When grown under short- day conditions, eafl plants were slightly pale green and had elongated peti oles, phenotypes that are observed in mutants altered in either phytochrome or the gibberellin (GA) response. eaf1 seed showed increased resistance to the GA biosynthesis inhibitor paclobutrazol, suggesting that GA metabolism and/or response had been altered. Comparison of eafl to other early-flower ing mutants revealed that eafl shifts to the adult phase early and flowers early, similarly to the phyB (phytochrome B) and spy (spindly) mutants. eaf 1 maps to chromosome 2, but defines a locus distinct from phyB, clf (curly leaf), and elf3 (early-flowering 3). These results demonstrate that eafl de fines a new locus involved in an autonomous pathway and may affect CA regul ation of flowering.