Photoperiodic Signaling and Senescence, an Ancient Solution to a Modern Problem?

Abstract

The length of the day (photoperiod) is a robust seasonal signal originated by earth orbital and translational movements, a resilient external cue to the global climate change, and a predictable hint to initiate or complete different developmental programs. In eukaryotic algae, the gene expression network that controls the cellular response to photoperiod also regulates other basic physiological functions such as starch synthesis or redox homeostasis. Land plants, evolving in a novel and demanding environment, imbued these external signals within the regulatory networks controlling organogenesis and developmental programs. Unlike algae that largely have to deal with cellular physical cues, within the course of evolution land plants had to transfer this external information from the receiving organs to the target tissues, and mobile signals such as hormones were recruited and incorporated in the regulomes. Control of senescence by photoperiod, as suggested in this perspective, would be an accurate way to feed seasonal information into a newly developed function (senescence) using an ancient route (photoperiodic signaling). This way, the plant would assure that two coordinated aspects of development such as flowering and organ senescence were sequentially controlled. As in the case of senescence, there is growing evidence to support the idea that harnessing the reliability of photoperiod regulation over other, more labile signaling pathways could be used as a robust breeding tool to enhance plants against the harmful effects of climate change.

Regulation of floral senescence in Arabidopsis by coordinated action of CONSTANS and jasmonate signaling

“…In previous studies, CO was identified as being differentially expressed in the shoot apical meristem during the early stages of floral differentiation, and although CO was upregulated, FT, its main target, was not (Wellmer et al, 2006;Chen et al, 2018). This hinted to a possible different role of CO compared with that described in induction of flowering by photoperiod (Sua ´rez-Lo ´pez et al, 2001;Serrano-Bueno et al, 2021). Here we describe the presence of CO protein in floral organs with a novel pattern of expression and a role in flower senescence.…”

The Photoperiod: Handling and Causing Stress in Plants

“…The perception of and response to photoperiods in plants require a sensing mechanism, which involves the detection of light (via photoreceptors or chloroplasts) and the measurement of time (via the circadian clock) ( Jackson, 2009 ; Serrano-Bueno et al, 2021 ).…”

“…The synchronization of the correct timing of protein stabilization during long days with the circadian-regulated expression of FKF1 , GI , and CDF1 is essential for photoperiodic responses, such as flowering. Interesting to mention is that the CO-FT-GI-CDF hub is conserved among distantly related flowering plants ( Serrano-Bueno et al, 2021 ).…”

“…Among the most prominent plant responses influenced by the photoperiod are the regulation of flowering time ( Carré, 2001 ; Song et al, 2015 ), tuberization ( Sarkar, 2010 ), bud setting, and dormancy ( Jackson, 2009 ; Singh et al, 2017 ). In annual plants, senescence is adjusted by the photoperiod ( Serrano-Bueno et al, 2021 ) and in perennial plants like trees, the growth cessation is influenced by season-dependent photoperiods ( Singh et al, 2017 ). In temperate climate zones but also in tropical regions, the photoperiod is the dominant environmental factor controlling the onset and end of the seasonal growing ( Adole et al, 2019 ).…”

Diverse photoperiodic gene expression patterns are likely mediated by distinct transcriptional systems in Arabidopsis

“…Photoperiod, or daylength, is a robust seasonal cue that is measured by organisms ranging from algae (Serrano-Bueno et al, 2021) and fungi (Roenneberg and Merrow, 2001), to higher plants (Thomas and Vince-Prue, 1996) and vertebrates (Gwinner, 2003). This circannual signal allows the anticipation of environmental changes and thus the coordination of long-term developmental and reproductive processes, such as tuberization in potatoes (Osnato et al, 2021) and maturation of animal gonads (Nakane and Yoshimura, 2019).…”