Full moonlight-induced circadian clock entrainment in Coffea arabica

J-C Breitler,A Dereeper,L Toniutti,D Djerrab,H Etienne,M Pratlong,D Severac,C Guittin,B Bertrand,S Leran

doi:10.1186/s12870-020-2238-4

Abstract

BackgroundIt is now well documented that moonlight affects the life cycle of invertebrates, birds, reptiles, and mammals. The lunisolar tide is also well-known to alter plant growth and development. However, although plants are known to be very photosensitive, few studies have been undertaken to explore the effect of moonlight on plant physiology.ResultsHere for the first time we report a massive transcriptional modification in Coffea arabica genes under full moonlight conditions, particularly at full moon zenith and 3 h later. Among the 3387 deregulated genes found in our study, the main core clock genes were affected.ConclusionsMoonlight also negatively influenced many genes involved in photosynthesis, chlorophyll biosynthesis and chloroplast machinery at the end of the night, suggesting that the full moon has a negative effect on primary photosynthetic machinery at dawn. Moreover, full moonlight promotes the transcription of major rhythmic redox genes and many heat shock proteins, suggesting that moonlight is perceived as stress. We confirmed this huge impact of weak light (less than 6 lx) on the transcription of circadian clock genes in controlled conditions mimicking full moonlight.

Highlights

It is well documented that moonlight affects the life cycle of invertebrates, birds, reptiles, and mammals
The wavelength of full moonlight is generally centered around 400 nm (580 nm for the sun) with a very low energy level (0.2 lx or 0.0024 μmol m− 2 s− 1)
Massive transcriptional up and down regulation induced by full moonlight Full moonlight was reported to induce transcriptional up or down regulation of many coffee leaf genes compared with new moon (NM) light (Fig. 2a)

Summary

Introduction

It is well documented that moonlight affects the life cycle of invertebrates, birds, reptiles, and mammals. The lunisolar tide is well-known to alter plant growth and development. Moonlight and the lunar cycle can affect reproduction, communication, foraging and predation in invertebrates, birds, reptiles, and mammals [1, 2]. Barlow’s work clearly demonstrated the impact of local gravimetric oscillations on plant growth and development. These gravimetric variations, i.e. the lunisolar gravity cycle or lunisolar tide, occur daily as result of the impact of the sun and moon on the earth’s surface gravity. Lunisolar tide influences plant phenomena such as leaf movement, stem elongation, fluctuations in tree stem diameter, root growth, biophoton emission by seedlings, and chlorophyll fluorescence [3]. Gallep and coworkers demonstrated co-variation between ultra-weak

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