Differential roles of nuclear and cytosolic GI in regulating plant circadian system

ABSTRACT: GIGANTEA (GI) is an important modulator of plant circadian system. Recent studies have reported that protein GI is localized in both nucleus and cytosol, and nuclear and cytosolic GI exert differential effect on plant circadian clock. We first generated GI-null mutants and transgenic Arabidopsis plants that expressed GI fused to green fluorescent protein gene (GIpro::GI-GFP) and GI-GFP with a nuclear localization signal (GIpro::GI-GFP-NLS) or with a nuclear export signal (GIpro::GI-GFP-NES) under the control of native promoter in GI-null mutants. To investigate differential roles of nuclear and cytosolic GI in regulating plant circadian clock, we performed genome-wide gene expression profiling for wild-type plants and the GI-transgenic plants at morning and evening, and analyzed complementation patterns of gi-2 lesion by nuclear and cytosolic GI. As a result, we identified four complementation patterns representing genes affected by only nuclear GI (GIN) or cytosolic GI (GIC), those by either GIN or GIC, and those by the action of both GIN and GIC. Furthermore, we compared the transgenic plants expressing GIpro::GI-GFP with WT and the other GI-transgenic plants to confirm whether abnormally expressed genes by the gi-2 mutation can be complemented by restoring protein GI. Wild-type plants (Col), GI-null mutants (gi-2), and the other transgenic gi-2 plants expressing GIpro::GI-GFP (called GI plants), GIpro::GI-GFP-NLS (called GI-NLS plants), and GIpro::GI-GFP-NES (called GI-NES plants) were grown for seven days under conditions of 16 h light and 8 h dark (LD) and harvested at 1h (ZT1) and 16 hr (ZT16) after the light is turned on, representing morning and evening, respectively. mRNA levels were measured from three biological replicates of Col, gi-2, GI-NLS, GI-NES, and GI.

ORGANISM(S): Arabidopsis thaliana

SUBMITTER: Seungmin Han 

PROVIDER: E-GEOD-47169 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress