PIFs- and COP1-HY5-mediated temperature signaling in higher plants

Abstract

Plants have to cope with the surrounding changing environmental stimuli to optimize their physiological and developmental response throughout their entire life cycle. Light and temperature are two critical environmental cues that fluctuate greatly during day-night cycles and seasonal changes. These two external signals coordinately control the plant growth and development. Distinct spectrum of light signals are perceived by a group of wavelength-specific photoreceptors in plants. PIFs and COP1-HY5 are two predominant signaling hubs that control the expression of a large number of light-responsive genes and subsequent light-mediated development in plants. In parallel, plants also transmit low or warm temperature signals to these two regulatory modules that precisely modulate the responsiveness of low or warm temperatures. The core component of circadian clock ELF3 integrates signals from light and warm temperatures to regulate physiological and developmental processes in plants. In this review, we summarize and discuss recent advances and progresses on PIFs-, COP1-HY5- and ELF3-mediated light, low or warm temperature signaling, and highlight emerging insights regarding the interactions between light and low or warm temperature signal transduction pathways in the control of plant growth.

The Role of Light Quality in Regulating Early Seedling Development

“…In addition, the regulation of ubiquitin−mediated protein degradation by PHYs is an important component of the PHY signaling machinery [ 33 ]. The COP1−SPA E3 ligase complex is a regulator that plays a central role downstream of various photoreceptors [ 45 , 46 , 47 ]. It targets several positive regulators of photomorphogenesis, such as HY5 (Elongated−Hypocotyl 5), leading to its destabilization and degradation in the dark through the 26S proteasome pathway [ 45 , 48 ].…”

Light signaling-mediated growth plasticity in Arabidopsis grown under high-temperature conditions

“…HY5 directly represses PIF4 transcription, and the degradation of HY5 results in the accumulation of PIF4 mRNA (Delker et al, 2014 ). HY5 also competes with PIF4 to occupy the PIF4 DNA-binding sites, adding another layer of antagonism to these two transcription factors (Bian et al, 2022 ; Gangappa and Kumar, 2017 ). In addition to its interactions with COP1, SPA1 also exerts some Ser/Thr kinase activity (Lee et al, 2020 ; Paik et al, 2019 ; Wang et al, 2021a ).…”

“…Over the past decade, many well-designed studies have illustrated how plants sense and signal high temperatures to regulate their growth and development. Interestingly, plant photoreceptors and light-signaling components play crucial roles in plant thermomorphogenesis, with several elegant review papers summarizing the interactions between light and temperature (Bian et al, 2022 ; Ding and Yang, 2022 ; Jin and Zhu, 2019 ; Li et al, 2022 ; Qi et al, 2022 ). Given this, we have avoided potential content overlap with these reviews by focusing on a discussion of the various interactions between light and temperature and their roles in the regulation of individual plant organ growth.…”

PIF transcription factors-versatile plant epigenome landscapers

“…One of the most critical PB component are the PIFs, a family of basic helix-loop-helix (bHLH) TFs which acts a transcriptional activators or repressors (Ni et al, 1998;Huq and Quail, 2002;Huq et al, 2004;Oh et al, 2004;Castillon et al, 2007;Leivar et al, 2008;Shen et al, 2008;Leivar and Quail, 2011;Leivar and Monte, 2014). The Arabidopsis genome encodes eight PIFs (PIF1-PIF8), which integrate phyB's environmental input into GRNs underlying light and temperature responses (Leivar and Quail, 2011;Jeong and Choi, 2013;Leivar and Monte, 2014;Pham et al, 2018;Bian et al, 2022;Han et al, 2023). PIF1/3/4/5 control the transition from skotomorphogenesis (SM) to photomorphogenesis (PM) by repressing light-responsive gene expression in the dark until light exposure initiates their phytochrome-mediated phosphorylation, ubiquitination and subsequent proteasomal degradation (Leivar and Quail, 2011;Leivar and Monte, 2014;Pham et al, 2018).…”