scholarly journals Exogenous melatonin improves growth in hulless barley seedlings under cold stress by influencing the expression rhythms of circadian clock genes

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10740
Author(s):  
Tianliang Chang ◽  
Yi Zhao ◽  
Hongyan He ◽  
Qianqian Xi ◽  
Jiayi Fu ◽  
...  

Background Melatonin is a hormone substance that exists in various living organisms. Since it was discovered in the pineal gland of cattle in 1956, the function of melatonin in animals has been roughly clarified. Nevertheless, in plants, the research on melatonin is still insufficient. Hulless barley (Hordeum vulgare L. var. nudum hook. f.) is a crop that originates from cultivated barley in the east, usually grown on the Qinghai-Tibet Plateau, becoming the most important food crop in this area. Although the genome and transcriptome research of highland barley has gradually increased recently years, there are still many problems about how hulless barley adapts to the cold climate of the Qinghai-Tibet Plateau. Methods In this study, we set three temperature conditions 25°C, 15°C, 5°C hulless barley seedlings, and at the same time soaked the hulless barley seeds with a 1 µM melatonin solution for 12 hours before the hulless barley seeds germinated. Afterwards, the growth and physiological indicators of hulless barley seedlings under different treatment conditions were determined. Meanwhile, the qRT-PCR method was used to determine the transcription level of the hulless barley circadian clock genes under different treatment conditions under continuous light conditions. Results The results showed the possible mechanism by which melatonin pretreatment can promote the growth of hulless barley under cold stress conditions by studying the effect of melatonin on the rhythm of the circadian clock system and some physiological indicators. The results revealed that the application of 1 µM melatonin could alleviate the growth inhibition of hulless barley seedlings caused by cold stress. In addition, exogenous melatonin could also restore the circadian rhythmic oscillation of circadian clock genes, such as HvCCA1 and HvTOC1, whose circadian rhythmic phenotypes were lost due to environmental cold stress. Additionally, the results confirmed that exogenous melatonin even reduced the accumulation of key physiological indicators under cold stress, including malondialdehyde and soluble sugars. Discussion Overall, these findings revealed an important mechanism that exogenous melatonin alleviated the inhibition of plant vegetative growths either by restoring the disrupted circadian rhythmic expression oscillations of clock genes, or by regulating the accumulation profiles of pivotal physiological indicators under cold stress.

mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Jie Yin ◽  
Yuying Li ◽  
Hui Han ◽  
Jie Ma ◽  
Gang Liu ◽  
...  

ABSTRACT Melatonin, a circadian hormone, has been reported to improve host lipid metabolism by reprogramming the gut microbiota, which also exhibits rhythmicity in a light/dark cycle. However, the effect of the administration of exogenous melatonin on the diurnal variation in the gut microbiota in mice fed a high-fat diet (HFD) is unclear. Here, we further confirmed the antiobesogenic effect of melatonin on mice fed an HFD for 2 weeks. Samples were collected every 4 h within a 24-h period, and diurnal rhythms of clock gene expression (Clock, Cry1, Cry2, Per1, and Per2) and serum lipid indexes varied with diurnal time. Notably, Clock and triglycerides (TG) showed a marked rhythm in the control in melatonin-treated mice but not in the HFD-fed mice. The rhythmicity of these parameters was similar between the control and melatonin-treated HFD-fed mice compared with that in the HFD group, indicating an improvement caused by melatonin in the diurnal clock of host metabolism in HFD-fed mice. Moreover, 16S rRNA gene sequencing showed that most microbes exhibited daily rhythmicity, and the trends were different for different groups and at different time points. We also identified several specific microbes that correlated with the circadian clock genes and serum lipid indexes, which might indicate the potential mechanism of action of melatonin in HFD-fed mice. In addition, effects of melatonin exposure during daytime or nighttime were compared, but a nonsignificant difference was noticed in response to HFD-induced lipid dysmetabolism. Interestingly, the responses of microbiota-transplanted mice to HFD feeding also varied at different transplantation times (8:00 and 16:00) and with different microbiota donors. In summary, the daily oscillations in the expression of circadian clock genes, serum lipid indexes, and the gut microbiota appeared to be driven by short-term feeding of an HFD, while administration of exogenous melatonin improved the composition and diurnal rhythmicity of some specific gut microbiota in HFD-fed mice. IMPORTANCE The gut microbiota is strongly shaped by a high-fat diet, and obese humans and animals are characterized by low gut microbial diversity and impaired gut microbiota compositions. Comprehensive data on mammalian gut metagenomes shows gut microbiota exhibit circadian rhythms, which is disturbed by a high-fat diet. On the other hand, melatonin is a natural and ubiquitous molecule showing multiple mechanisms of regulating the circadian clock and lipid metabolism, while the role of melatonin in the regulation of the diurnal patterns of gut microbial structure and function in obese animals is not yet known. This study delineates an intricate picture of melatonin-gut microbiota circadian rhythms and may provide insight for obesity intervention.


2019 ◽  
Author(s):  
Jie Yin ◽  
Yuying Li ◽  
Hui Han ◽  
Gang Liu ◽  
Xin Wu ◽  
...  

AbstractMelatonin, a circadian hormone, has been reported to improve host lipid metabolism by reprogramming gut microbiota, which also exhibits rhythmicity in a light/dark cycle. However, the effect of admistartion of exogenous melatonin on the diurnal variation in gut microbiota in high fat diet (HFD)-fed mice is obscure. Here, we further confirmed the anti-obesogenic effect of melatonin on in mice feed with HFD for two weeks. Samples were collected every 4 h within a 24-h period and diurnal rhythms of clock genes expression (Clock, Cry1, Cry2, Per1, and Per2) and serum lipid indexes varied with diurnal time. Notably, Clock and triglycerides (TG) showed a marked rhythm only in the control and melatonin treated mice, but not in the HFD-fed mice. Rhythmicity of these parameters were similar between control and melatonin treated HFD mice compared with the HFD group, indicating an improvement of melatonin in the diurnal clock of host metabolism in HFD-fed mice. 16S rDNA sequencing showed that most microbiota exhibited a daily rhythmicity and the trends differentiated at different groups and different time points. We also identified several specific microbiota correlating with the circadian clock genes and serum lipid indexes, which might contribute the potential mechanism of melatonin in HFD-fed mice. Interestingly, administration of exogenous melatonin only at daytime exhibited higher resistance to HFD-induced lipid dysmetabolism than nighttime treatment companying with altered gut microbiota (Lactobacillus, Intestinimonas, and Oscillibacter). Importantly, the responses of microbiota transplanted mice to HFD feeding also varied at different transplanting times (8:00 and 16:00) and different microbiota donors. In summary, daily oscillations in the expression of circadian clock genes, serum lipid indexes, and gut microbiota, appears to be driven by a short-time feeding of an HFD. Administration of exogenous melatonin improved the compositions and diurnal rhythmicity of gut microbiota, which might be linked to host diurnal rhythm and metabolism.ImportancePrevious studies show that a circadian hormone, melatonin, involves in host lipid metabolism by reprogramming gut microbiota, which also exhibits rhythmicity in a light/dark cycle. However, the effect of melatonin drinking on the diurnal variation in gut microbiota in high fat diet-fed mice is obscure. Here, we found that 24-h oscillations were widely occurred in circadian clock genes, serum lipid indexes, and gut microbiota. Melatonin drinking improved the compositions and circadian rhythmicity of gut microbiota, which might be linked to host circadian rhythm and metabolism.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yanlei Yue ◽  
Ze Jiang ◽  
Enoch Sapey ◽  
Tingting Wu ◽  
Shi Sun ◽  
...  

Abstract Background In soybean, some circadian clock genes have been identified as loci for maturity traits. However, the effects of these genes on soybean circadian rhythmicity and their impacts on maturity are unclear. Results We used two geographically, phenotypically and genetically distinct cultivars, conventional juvenile Zhonghuang 24 (with functional J/GmELF3a, a homolog of the circadian clock indispensable component EARLY FLOWERING 3) and long juvenile Huaxia 3 (with dysfunctional j/Gmelf3a) to dissect the soybean circadian clock with time-series transcriptomal RNA-Seq analysis of unifoliate leaves on a day scale. The results showed that several known circadian clock components, including RVE1, GI, LUX and TOC1, phase differently in soybean than in Arabidopsis, demonstrating that the soybean circadian clock is obviously different from the canonical model in Arabidopsis. In contrast to the observation that ELF3 dysfunction results in clock arrhythmia in Arabidopsis, the circadian clock is conserved in soybean regardless of the functional status of J/GmELF3a. Soybean exhibits a circadian rhythmicity in both gene expression and alternative splicing. Genes can be grouped into six clusters, C1-C6, with different expression profiles. Many more genes are grouped into the night clusters (C4-C6) than in the day cluster (C2), showing that night is essential for gene expression and regulation. Moreover, soybean chromosomes are activated with a circadian rhythmicity, indicating that high-order chromosome structure might impact circadian rhythmicity. Interestingly, night time points were clustered in one group, while day time points were separated into two groups, morning and afternoon, demonstrating that morning and afternoon are representative of different environments for soybean growth and development. However, no genes were consistently differentially expressed over different time-points, indicating that it is necessary to perform a circadian rhythmicity analysis to more thoroughly dissect the function of a gene. Moreover, the analysis of the circadian rhythmicity of the GmFT family showed that GmELF3a might phase- and amplitude-modulate the GmFT family to regulate the juvenility and maturity traits of soybean. Conclusions These results and the resultant RNA-seq data should be helpful in understanding the soybean circadian clock and elucidating the connection between the circadian clock and soybean maturity.


2021 ◽  
pp. 102866
Author(s):  
Kun Xiang ◽  
Zhiwei Xu ◽  
Yu-Qian Hu ◽  
Yi-Sheng He ◽  
Guo-Cui Wu ◽  
...  

2002 ◽  
pp. 411-425
Author(s):  
Michael H. Hastings ◽  
Verdun M. King ◽  
Elizabeth S. Maywood

2021 ◽  
Author(s):  
Qianzhun Huang ◽  
Xiaoyang Su ◽  
Ning Fang ◽  
Jian Huang

Abstract Background: Dysregulated circadian dynamic balance is strongly associated with cancer development. However, biological functions of circadian rhythms in lung adenocarcinoma (LUAD) have not been elucidated. This study aimed at valuating the modulatory effects of circadian rhythms in the LUAD tumor microenvironment.Methods: Multiple open-source bioinformatics research platforms are used to comprehensively elucidate the expression level, prognosis, potential biological function, drug sensitivity, and immune microenvironment of circadian clock genes in LUAD.Results: Most circadian clock genes in LUAD are dysregulated and are strongly correlated with patient prognosis, and missense mutations at splicing sites of these genes. Besides, these genes are closely associated with some well-known cancer-related marker pathways, which are mainly involved in the inhibition of the Apoptosis, Cell cycle, and DNA Damage Response Pathway. Furthermore, functional enrichment analysis revealedthat circadian clock genes regulate transcription factor activities and circadian rhythms in LUAD tissues. As for drug sensitivity, high expression of CLOCK, CRY1, and NR1D2 as well as suppressedPER2 and CRY2 expression levels are associated with drug resistance. The expression levels of circadian clock genes in LUAD correlate with immune infiltration and are involved in the regulation of immunosuppression.Conclusions: Our multi-omics analysis provides a more comprehensive understanding of the molecular mechanisms of the circadian clock genes in LUAD and provides new insights for a more precise screening of prognostic biomarkers and immunotherapy.


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