Photoperiod sensing of the circadian clock is controlled by EARLY FLOWERING 3 and GIGANTEA

TY - JOUR

T1 - Photoperiod sensing of the circadian clock is controlled by EARLY FLOWERING 3 and GIGANTEA

AU - Anwer, Muhammad Usman

AU - Davis, Amanda M

AU - Davis, Seth Jon

AU - Quint, Marcel

N1 - © 2019 The Authors

PY - 2019/11/6

Y1 - 2019/11/6

N2 - ELF3 and GI are two important components of the Arabidopsis circadian clock. They are not on-ly essential for the oscillator function but are also pivotal in mediating light inputs to the oscillator. Lack of either results in a defective oscillator causing severely compromised output pathways, such as photoperiodic flowering and hypocotyl elongation. Although single loss of function mu-tants of ELF3 and GI have been well-studied, their genetic interaction remains unclear. We gen-erated an elf3 gi double mutant to study their genetic relationship in clock-controlled growth and phase transition phenotypes. We found that ELF3 and GI repress growth differentially during the night and the day, respectively. Circadian clock assays revealed that ELF3 and GI are essential Zeitnehmers that enable the oscillator to synchronize the endogenous cellular mechanisms to external environmental signals. In their absence, the circadian oscillator fails to synchronize to the light-dark cycles even under diurnal conditions. Consequently, clock-mediated photoperiod-responsive growth and development are completely lost in plants lacking both genes, suggesting that ELF3 and GI together convey photoperiod sensing to the central oscillator. Since ELF3 and GI are conserved across flowering plants and represent important breeding and domestication targets, our data highlight the possibility of developing photoperiod-insensitive crops by adjusting the allelic combination of these two key genes.

AB - ELF3 and GI are two important components of the Arabidopsis circadian clock. They are not on-ly essential for the oscillator function but are also pivotal in mediating light inputs to the oscillator. Lack of either results in a defective oscillator causing severely compromised output pathways, such as photoperiodic flowering and hypocotyl elongation. Although single loss of function mu-tants of ELF3 and GI have been well-studied, their genetic interaction remains unclear. We gen-erated an elf3 gi double mutant to study their genetic relationship in clock-controlled growth and phase transition phenotypes. We found that ELF3 and GI repress growth differentially during the night and the day, respectively. Circadian clock assays revealed that ELF3 and GI are essential Zeitnehmers that enable the oscillator to synchronize the endogenous cellular mechanisms to external environmental signals. In their absence, the circadian oscillator fails to synchronize to the light-dark cycles even under diurnal conditions. Consequently, clock-mediated photoperiod-responsive growth and development are completely lost in plants lacking both genes, suggesting that ELF3 and GI together convey photoperiod sensing to the central oscillator. Since ELF3 and GI are conserved across flowering plants and represent important breeding and domestication targets, our data highlight the possibility of developing photoperiod-insensitive crops by adjusting the allelic combination of these two key genes.

U2 - 10.1111/tpj.14604

DO - 10.1111/tpj.14604

M3 - Article

SN - 0960-7412

SP - 1

EP - 14

JO - The Plant journal

JF - The Plant journal

ER -