In particular, to test if their function is affected after phosphorylation by phytochrome, and to understand how they modulate phytochrome signaling. Clone and characterize novel mutants affected in phytochrome signaling Despite much recent progress in the characterization of phytochromes we still know relatively little about signaling components acting downstream. Five phytochrome signaling intermediates have been cloned during the past 2 years but based on the complexity of the light response and the number of genetic loci affected in those processes many remained to be identified. These mutants will be further studied here in Geneva. Crosses to relevant mutants have shown that they are not affected in previously identified genes.
Adult plants are difficult to distinguish from wild-types.
I. This is likely to represent a newly identified locus because no published far-red insensitive mutant maps there. Panel A shows the morphology of 6 days old Arabidopsis seedlings grown either in the dark or in the light. Panel B shows the phenotype of Col, phyA and rsf1 seedlings grown in far-red light. All these phenotypes are very similar to those of a weak phyB mutant. Crosses to phyB- plants have ruled out the possibility of dsr1 being a weak phyB allele.