Transcriptional regulatory network of the light signaling pathways

Abstract

The developmental program by which plants respond is tightly controlled by a complex cascade in which photoreceptors perceive and transduce the light signals that drive signaling processes and direct the transcriptional reprogramming, yielding specific cellular responses. The molecular mechanisms involved in the transcriptional regulation include light-regulated nuclear localization (the phytochromes and UVR8) and nuclear accumulation (the cryptochrome, cry2) of photoreceptors. This regulatory cascade also includes master regulatory transcription factors (TFs) that bridge photoreceptor activation with chromatin remodeling and regulate the expression of numerous light-responsive genes. Light signaling-related TFs often function as signal convergence points in concert with TFs in other signaling pathways to integrate complex endogenous and environmental cues that help the plant adapt to the surrounding environment. Increasing evidence suggests that chromatin modifications play a critical role in regulating lightresponsive gene expression and provide an additional layer of light signaling regulation. Here, we provide an overview of our current knowledge of the transcriptional regulatory network involved in the light response, particularly the roles of TFs and chromatin in regulating light-responsive gene expression.

COLD-REGULATED GENE27 Integrates Signals from Light and the Circadian Clock to Promote Hypocotyl Growth in Arabidopsis

“…Light signals of various wavelengths are perceived by several photoreceptor families, including phytochromes (red and far-red light), cryptochromes (blue light), phototropins (blue light), and UV-B RESISTANCE LOCUS8 (UVR8, for UV light; Gallagher et al, 1988;Sharrock and Quail, 1989;Lin et al, 1995;Guo et al, 1998;Rizzini et al, 2011;Christie et al, 2012). These photoreceptors are responsible for transducing diverse light information to downstream light signaling components to initiate a variety of cellular and physiological processes (Chen et al, 2014;Ma et al, 2016;Pedmale et al, 2016;Paik and Huq, 2019;Xu, 2019;Jing and Lin, 2020;Yadav et al, 2020;Yu and Liu, 2020). CONSTITUTIVELY PHOTOMORPHOGENIC/DE-ETIOLATED/FUSCA (COP/DET/ FUS) proteins, acting directly downstream of photoreceptors, are biologically active in the nucleus and maintain skotomorphogenesis in the dark (Lau and Deng, 2012;Hoecker, 2017;Podolec and Ulm, 2018;Han et al, 2020).…”

Transcriptional Regulation of Photomorphogenesis in Brassica Napus Under Different Light Quality

“…Previous studies showed that PHYA, as a type I phytochrome, accumulates abundantly in the dark, and it is degraded or repressed under both red and farred light exposure. PHYB belongs to Type II phytochrome, and it is stable in the light [1,5]. In this study, two PHYA transcripts were accumulated in dark, and were signi cantly decreased in all light conditions ( Fig.…”

“…Transcriptional reprograming, including signal transduction and activation or inhibition of downstream pathways (phytohormone and plant growth), plays a vital role in photomorphogenesis [1,5]. In order to investigate the transcriptional regulation in response to different light quality, we performed transcriptome analysis of seedling under dark and four light quality.…”

The role of light in regulating seed dormancy and germination

“…UVRESISTANCE LOCUS8 (UVR8) senses UV-B (280-320 nm) light (Rizzini et al 2011). These photoreceptors mediate light signals that remodel the global transcriptional program by selectively interacting with transcription factors or E3 ubiquitin ligases, which regulate the stability of transcriptional regulators (Chen and Chory 2011;Leivar and Monte 2014;Shi et al 2018;Legris et al 2019;Jing and Lin 2020).…”

“…The light signaling pathway has been extensively reviewed (Lau and Deng 2012;Huang et al 2014;Liang et al 2019;Jing and Lin 2020). Here we emphasize some of the key factors in this pathway involved in controlling seed dormancy and germination.…”