Thermal imaging as a noninvasive technique for analyzing circadian rhythms in plants

Abstract

Endogenous (~24 circadian) rhythms control an enormously diverse range of processes in plants and are, increasingly, the target of studies aimed at understanding plant performance. Although in the previous few decades most plant circadian research has focused on Arabidopsis, there is a pressing need for low-cost, high-throughput tools for analyzing rhythms in a wider variety of species. The present contribution investigates using circadian temperature oscillations as a novel marker for assaying plant circadian rhythms.A thermal imaging platform was set up to measure diel and circadian rhythms in different plant species, in wild-type and circadian mutant plants, and in leaves and flowers. Results from the thermal imaging technique were compared with those from other established circadian assay techniques.All of the dicot and monocot species examined showed robust circadian rhythms of leaf surface temperature; the effects of circadian mutations on thermocycles were similar to those reported using other techniques. In Petunia 9 atkinsiana plants circadian oscillations were observed in both leaves and flowers.Thermal imaging is an extremely useful technique for analyzing circadian rhythms in plants. It is predicted that the ability to make very high temporal resolution measurements may facilitate the discovery of novel aspects of circadian control. conceived and devised the experiments and wrote the manuscript; and YD carried out the experiments. ORCIDRachel M. Green https://orcid.org/

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

“…The dicot and monocot leaf surface temperature displays robust circadian rhythm (Dakhiya & Green, 2019), which indicates that plants respond to the fluctuations of environmental temperature during the day, and regulate the loss or preservation of water from the leaf through transpiration system. To find out how GmLCLs affect the response of leaves to water shortage, we performed analysis on physiological leaf trait at different times during the day.…”

“…Here, mutation of GmLCL caused a significant increase in leaf temperature in drought‐resistant leaves (Figure 4a,b). Leaf temperature is known to be regulated by the circadian clock and exhibits a free‐oscillating rhythm (Dakhiya & Green, 2019). It is reported that the modulation of leaf temperature largely depends on plant transpiration, and transpiration intensity is partially regulated by the circadian movement of stomata, which has been observed in many species (Gorton et al, 1989; Hassidim et al, 2017; Martin & Meidner, 1971; Sayre, 1926).…”

Exploring Seasonal and Circadian Rhythms in Structural Traits of Field Maize from LiDAR Time Series

“…Besides, it is interesting to quantify the impact of environmental tress (e.g., cold) on the normal growth rhythms if we know the mechanism of the biological clock. Finally, the seasonal and circadian rhythms were studied using TLS data only; multisource remote sensing data are expected to use, such as using hyperspectral, thermal, and chlorophyll fluorescence to track the physiological rhythms [ 12 , 64 ]. Meanwhile, simultaneous measurement of changes in plant physiology (e.g., stomatal movement), biochemistry, and metabolite indicators have important prospects for explaining changes in plant structural rhythms [ 7 , 65 , 66 ].…”

“…Plant structural rhythm is regulated by both the biological clock and environment, which can directly capture plant structure dynamics and their relationships with plant functions [ 10 ]. It is becoming a promising direction to understand plant rhythm which is now more easily accessible with the development of sensing technologies, computer vision, and deep learning algorithms [ 11 , 12 ].…”

Thermal Imaging for Plant Stress Detection and Phenotyping

“…Thermography also appears as a very convenient tool to study other aspects of plants that are out of the scope of this review, such as seeds vigor [173], investigations on circadian rhythms [174,175], the effects of microgravity on plant physiology [176], interactions with plant-symbiotic microorganisms [177][178][179][180], the impact of climate change in ecology [15], or food industry [181]. Thermography is also a very relevant tool for screening for mutants [182,183] and cultivars [21] with desirable phenotypes such as pathogen resistance or improved performance upon certain abiotic stress conditions.…”