MUTANTS IN ARABIDOPSIS-THALIANA ALTERED IN EPICUTICULAR WAX AND LEAF MORPHOLOGY

We report eight new mutants in Arabidopsis thaliana possessing altered leaf morphology and epicuticular wax. These were isolated from a T-DN A-mutagenized population using a visual screen for altered leaf reflec tance, i.e. increased glaucousness or glossiness. The mutants were pla ced into three distinct classes based on alterations in overall plant morphology: knobhead (knb), bicentifolia (bcf), and wax. The four knb mutants formed cailus-like growths in the axillary region of the roset te leaves and apical meristem, the two bcf mutants produced hundreds o f narrow leaves, and the two wax mutants had leaves and stems that wer e more glossy than wild type and organs that fused during early develo pment. Leaves of knb and bcf were more glaucous and abnormally shaped than wild type. Epicuticular wax crystals over knb and bcf leaf surfac es (where none were present on wild type) likely contributed to their more glaucous appearance. In contrast, the glossy appearance of the wa x mutants was associated with a reduced epicuticular wax load on both leaves and stems. One representative from each phenotypic class was se lected for detailed analyses of epicuticular wax chemistry. All three lines, knb1, bcf1, and wax1, had dramatic alterations in the total amo unts and relative proportions of their leaf epicuticular wax constitue nts.