Focusing on the nuclear and subnuclear dynamics of light and circadian signalling

Abstract

Circadian clocks provide organisms the ability to synchronize their internal physiological responses with the external environment. This process, termed entrainment, occurs through the perception of internal and external stimuli. As with other organisms, in plants, the perception of light is a critical for the entrainment and sustainment of circadian rhythms. Red, blue, far-red, and UV-B light are perceived by the oscillator through the activity of photoreceptors. Four classes of photoreceptors signal to the oscillator: phytochromes, cryptochromes, UVR8, and LOV-KELCH domain proteins.In most cases, these photoreceptors localize to the nucleus in response to light and can associate to subnuclear structures to initiate downstream signalling. In this review, we will highlight the recent advances made in understanding the mechanisms facilitating the nuclear and subnuclear localization of photoreceptors and the role these subnuclear bodies have in photoreceptor signalling, including to the oscillator.We will also highlight recent progress that has been made in understanding the regulation of the nuclear and subnuclear localization of components of the plant circadian clock.

Then and now

“…Photoreceptors for red, far‐red, blue, and UV‐B light facilitate the input of light into the circadian clock, which synchronizes physiological processes in plants with the external environment. Ronald and Davis () highlight the recent advances made in understanding the mechanisms controlling the nuclear and sub‐nuclear localization of photoreceptors and the role of sub‐nuclear bodies in photoreceptor signalling.…”

GmLCLs negatively regulate ABA perception and signalling genes in soybean leaf dehydration response

“…The circadian clock, as an internal time‐keeping mechanism, synchronizes an organism with daily changes of environmental cues (Golden, 2020; Johnson & Hastings, 1986; McClung, 2011; Ronald & Davis, 2019; Young & Kay, 2001). The core oscillators drive circadian rhythms, which regulate virtually all aspects of physiology including gene expression, metabolism, hormone secretion and other physiological processes (Atamian & Harmer, 2016; Creux & Harmer, 2019; Rubin et al, 2017; Webb, Seki, Satake, & Caldana, 2019).…”

Functional characterization of mungbean CONSTANS-LIKE genes reveals a key role for CONSTANS-LIKE 2 in the control of flowering time in A. thaliana under short-day conditions

“…Several functional pathways have been identi ed that regulate the switch from vegetative to reproductive development. These include the photoperiodic, vernalization, ambient temperature, plant hormone, and autonomous owering pathways [1,[4][5][6][7][8][9][10]. Within these pathways, a number of genes have been identi ed as involved in owering time regulation, including CONSTANS-LIKE (COL) genes, phosphatidyl ethanolamine-binding protein (PEBP) genes and several members of MADS-Box gene family [1][2][11][12][13][14][15][16][17][18][19].…”