Interaction of Light and Temperature Signalling in Plants

Abstract

For plants, light is not only an energy source but also a developmental signal. The colour, intensity, duration and direction of light that a plant receives has a profound effect on its development across all life phases. Mild changes in ambient temperature also have a dramatic effect on plant development, many of which mirror those caused by light. In recent years, it has become apparent that this similarity in phenotypes is due to extensive overlap between components of the light and temperature signalling pathways. This overlap occurs at the level of perception, downstream signalling modules and hormonal response. As a result of this, the photo‐ and thermal responses of plants should always be considered within the context of the prevailing light and temperature conditions. Key Concepts Light and temperature have similar effects on plant development. Both signalling pathways are tightly integrated at the level of signal perception, signal transduction and hormonal responses. The response to both light and temperature centres on a core set of transcriptional regulators. The activity of some photoreceptors is temperature‐dependent. Light and temperature responses should always be considered in the context of one and other.

Hot topic: Thermosensing in plants

“…There is extensive cross‐talk between light and temperature signalling in plants (Hayes, 2020). Plants perceive light conditions with at least five types of photoreceptors, that is, (a) phytochromes, (b) cryptochromes, (c) phototropins, (d) zeitlupes and (e) UV Resistance Locus 8 (UVR8) (Voitsekhovskaja, 2019).…”

“…The absorption of light by phytochromobilin induces its isomerisation, and this translates to conformational changes in phytochrome structure. R light promotes a shift to the active form of phytochrome (Pfr), whereas FR light promotes reversion to the inactive form (Pr) (Hayes, 2020). Importantly, Pfr can also spontaneously revert to Pr, and this process is temperature‐dependent.…”

“…Zeitlupes contain a LOV domain with a similar activation mechanism to phototropins (Pudasaini et al, 2017). If the rate of zeitlupe inactivation is increased at warm temperatures, this could potentially reduce the pace of the clock at warm temperatures (a process known as temperature compensation) (Hayes, 2020). Several years ago, zeitlupe was identified as a quantitative trait locus for natural variation in temperature compensation in Arabidopsis (Edwards, Lynn, Gyula, Nagy, & Millar, 2005) and so it would be interesting to experimentally test this hypothesis.…”

Molecular pathways regulating elongation of aerial plant organs: a focus on light, the circadian clock, and temperature

“…A suite of photoreceptors found in plants mediate the growth responses of hypocotyls and petioles to environmental cues (reviewed in Hayes, 2020). Collectively, these photoreceptors have evolved the ability to sense not only light of several different wavelengths but also changes in ambient temperature.…”

Keep Cool and Open Up: Temperature-Induced Stomatal Opening

“…1). In theory, temperature can be sensed by other photoreceptors that are similarly deactivated, as is the case for phyB and the phototropins, or by changes in membrane fluidity or RNA translation (discussed by Hayes, 2020). Interestingly, the phyB-PIF4 temperature signaling cascade seems to induce irreversible growth and developmental changes, such as stem elongation, early flowering, and stomata development.…”