The Importance of the Circadian Clock in Regulating Plant Metabolism

Abstract

Carbohydrates are the primary energy source for plant development. Plants synthesize sucrose in source organs and transport them to sink organs during plant growth. This metabolism is sensitive to environmental changes in light quantity, quality, and photoperiod. In the daytime, the synthesis of sucrose and starch accumulates, and starch is degraded at nighttime. The circadian clock genes provide plants with information on the daily environmental changes and directly control many developmental processes, which are related to the path of primary metabolites throughout the life cycle. The circadian clock mechanism and processes of metabolism controlled by the circadian rhythm were studied in the model plant Arabidopsis and in the crops potato and rice. However, the translation of molecular mechanisms obtained from studies of model plants to crop plants is still difficult. Crop plants have specific organs such as edible seed and tuber that increase the size or accumulate valuable metabolites by harvestable metabolic components. Human consumers are interested in the regulation and promotion of these agriculturally significant crops. Circadian clock manipulation may suggest various strategies for the increased productivity of food crops through using environmental signal or overcoming environmental stress.

Non-Catalytic Subunits Facilitate Quaternary Organization of Plastidic Acetyl-CoA Carboxylase

“…Specifically, we grew the plants under continuous illumination, which avoids complexities associated with a diurnal light regime, whereas Keereetaweep et al (2018) grew plants using a 16-h illuminated/8-h darkness lighting regime. Such illumination regimes are known environmental modulators of fatty acid accumulation traits (Nakamura et al, 2014;Kim et al, 2017) and may be the source of the different findings in the two studies. In addition, in our study and in the study by Keereetaweep et al (2018), the identical badc3-1 allele was used in both studies; the GABI_170E12 allele obtained from Gabi-Kat and CS2103834, respectively, and these are one and the same (see https://abrc.osu.edu/stocks?search%5Btaxon %5D5Arabidopsis1thaliana&search%5Bsearch_text% 5D5at3g15690&search%5Bmaterial_type%5D%5B% 5D5seed&search%5Bsearch_fields%5D5AGI1locus1identifier).…”

A comprehensive time‐course metabolite profiling of the model cyanobacterium Synechocystis sp. PCC 6803 under diurnal light:dark cycles

“…Phototrophs have evolved under natural day/night LD cycles of sunlight availability where fitness depends on the efficient and timely capture of photons. Acclimation to changing light quality (Ho et al ., ) and quantity (Muramatsu and Hihara, ) has been studied extensively, as has circadian rhythms in plants (Kim et al ., ; Johansson and Koster, ) and cyanobacteria (Aoki et al ., , ). The cyanobacterial circadian clock has been elucidated in Synechococcus elongatus sp.…”

Anatomy, chlorophyll content and photosynthetic performance in current-year and previous-year Aleppo pine (Pinus halepensis Mill.) needles

“…Such differences of starch accumulation are considered to be a consequence of disturbed source to sink transport of sugars (Lemoine et al 2013). The normal daily dynamics of starch accumulation, where starch accumulates during the daytime and degrades at night, is regulated by circadian clock genes (Kim et al 2017). The growth processes in young CY needles likely demand intensive carbon allocation from the mesophyll to other sink tissues.…”