The Arabidopsis thaliana late-flowering mutation gigantea (GI) alters the circadian period and abiotic stress resistance. Now, C. Robertson McClung and colleagues report the fine mapping and cloning of the causal polymorphism in the Brassica rapa GI locus using recombinant inbred lines and show that it is responsible for variation in cold and salt tolerance (Proc. Natl. Acad. Sci. USA 112, 905–910, 2015). Null alleles for this gene were then identified among B. rapa TILLING mutants, and the authors show that these plants were arrhythmic or had abnormally long circadian periods in response to high temperature, as in Arabidopsis. The B. rapa alleles from the two parental strains could both rescue the photoperiodic flowering defect of the Arabidopsis gi null mutant. However, only one of the two B. rapa alleles was able to rescue the mutant phenotypes of increased freezing tolerance, decreased nitrogen accumulation and increased salt resistance. These results indicate that the effect of GI on flowering time is independent from its role in abiotic stress resistance and that these functions can be separated at the genetic level, which may have practical implications for targeted breeding programs in Brassica crops.