Circadian clocks are endogenous timers that enable plants to synchronize biological processes with daily and seasonal environmental conditions in order to allocate resources during the most beneficial times of day and...Circadian clocks are endogenous timers that enable plants to synchronize biological processes with daily and seasonal environmental conditions in order to allocate resources during the most beneficial times of day and year. The circadian clock regulates a number of central plant activities, including growth, develop- ment, and reproduction, primarily through controlling a substantial proportion of transcriptional activity and protein function. This review examines the roles that alleles of circadian clock genes have played in domestication and improvement of crop plants. The focus here is on three groups of circadian clock genes essential to clock function in Arabidopsis thaliana： PSEUDO-RESPONSE REGULATORs, GIGANTEA, and the evening complex genes EARL Y FLOWERING 3, EARLY FLOWERING 4, and LUX ARRHYTHMO. Homol- ogous genes from each group underlie quantitative trait loci that have beneficial influences on key agricul- tural traits, especially flowering time but also yield, biomass, and biennial growth habit. Emerging insights into circadian clock regulation of other fundamental plant processes, including responses to abiotic and biotic stresses, are discussed to highlight promising avenues for further crop improvement.展开更多
Heading date is a critical trait that determines cropping seasons and regional adaptability in rice （Oryza sativa）. Research efforts during the last decade have identified some important photoperiod pathway genes th...Heading date is a critical trait that determines cropping seasons and regional adaptability in rice （Oryza sativa）. Research efforts during the last decade have identified some important photoperiod pathway genes that are conserved between Arabidopsis and rice. In this study, we identified a novel gene, Oryza sativa ELF3 （OsELF3）, which is a putative homolog of the ELF3 gene in Arabidopsis thaliana. OsELF3 was required for the control of heading date under long-day conditions. Its Tos17-tagging mutants exhibited a delayed heading date phenotype only under long-day, but not short-day, conditions. OsELF3 was highly expressed in leaf blades, and the OsELF3 protein was localized in the nucleolus. An obvious diurnal rhythm of OsELF3 transcript level was observed, with a trough in the early day and a peak in the late night in wild-type plants. However, this expression pattern was disrupted in oself3 mutants. Further inves- tigations showed that the expression of OsGI and Ghd7 was up-regulated in the oself3 mutant, indicating that OsELF3 acts as a negative regulator upstream of OsGI and Ghd7 in the flowering-time control under long-day conditions. The rhythmic expression of circadian clock-related genes, including some OsPRR members, was obviously affected in oself3 mutants. Our results indicated that OsELF3 acts as a floral activator in the long-day photoperiodic pathway via its cross- talk with the circadian clock in rice.展开更多
To date,most current reports on the development and optimization of artificial lighting sources have focused on the energy performance levels and limited color qualities of white light-emitting diodes(LEDs).However,th...To date,most current reports on the development and optimization of artificial lighting sources have focused on the energy performance levels and limited color qualities of white light-emitting diodes(LEDs).However,these properties are insufficient in terms of representing all performance levels required when adjusting white LEDs for healthy and smart lighting.Here,we introduce essential and advanced figures of merit pertaining to circadian performance as well as vision performance and color quality.We compare all possible properties of commercialized artificial lighting,daylight and four-package white LEDs which consist of long-wavelength pass dichroic filter(LPDF)-capped,phosphor-converted red,amber and green LEDs(pc-LEDs)and a blue LED.We show that these tunable four-package white LEDs produce a tunable circadian effect for melatonin suppression/secretion,a high color quality for color perception/reproduction,high efficiency for energy savings and tunable figures of merit for the smart LED lighting market.展开更多
PHYTOCHROME-INTERACTING FACTORs （PIFs） are members of the basic helix-loop-helix （bHLH） family of transcription factors in Arabidopsis. Since their discovery in phytochrome-mediated light signaling pathways, recen...PHYTOCHROME-INTERACTING FACTORs （PIFs） are members of the basic helix-loop-helix （bHLH） family of transcription factors in Arabidopsis. Since their discovery in phytochrome-mediated light signaling pathways, recent studies have unraveled new functions of PIFs in integrating multiple signaling pathways not only through their role as transcription factors directly targeting gene expression but also by interacting with diverse groups of factors to optimize plant growth and development. These include endogenous （e.g., hormonal） as well as abiotic （light, circadian, and elevated temperature） and biotic （defense responses） pathways. PIFs interact with key factors in each of these pathways and tailor the outcome of the signal integration among these pathways. This review discusses the roles of PIFs as pivotal signal integrators in regulating plant growth and development.展开更多
Mounting research evidence demonstrates a significant negative impact of circadian disruption on human health. Shift work, chronic jet lag and sleep disturbances are associated with increased incidence of metabolic sy...Mounting research evidence demonstrates a significant negative impact of circadian disruption on human health. Shift work, chronic jet lag and sleep disturbances are associated with increased incidence of metabolic syndrome, and consequently result in obesity, type 2 diabetes and dyslipidemia.Here, these associations are reviewed with respect to liver metabolism and disease.展开更多
Sleep disorders have become a global issue,and discovering their causes and consequences are the focus of many research endeavors.An estimated 70 million Americans suffer from some form of sleep disorder.Certain sleep...Sleep disorders have become a global issue,and discovering their causes and consequences are the focus of many research endeavors.An estimated 70 million Americans suffer from some form of sleep disorder.Certain sleep disorders have been shown to cause neurocognitive impairment such as decreased cognitive ability,slower response times and performance detriments.Recent research suggests that individuals with sleep abnormalities are also at greater risk of serious adverse health,economic consequences,and most importantly increased all-cause mortality.Several research studies support the associations among sleep,immune function and inflammation.Here,we review the current research linking sleep,immune function,and gastrointestinal diseases and discuss the interdependent relationship between sleep and these gastrointestinal disorders.Different physiologic processes including immune system and inflammatory cytokines help regulate the sleep.The inflammatory cytokines such as tumor necrosis factor,interleukin-1(IL-1),and IL-6 have been shown to be a significant contributor of sleep disturbances.On the other hand,sleep disturbances such as sleep deprivation have been shown to up regulate these inflammatory cytokines.Alterations in these cytokine levels have been demonstrated in certain gastrointestinal diseases such as inflammatory bowel disease,gastro-esophageal reflux,liver disorders and colorectal cancer.In turn,abnormal sleep brought on by these diseases is shown to contribute to the severity of these same gastrointestinal diseases.Knowledge of these relationships will allow gastroenterologists a great opportunity to enhance the care of their patients.展开更多
A new mammalian photoreceptor was recently discovered to reside in the ganglion cell layer of the inner retina.These intrinsically photosensitive retinal ganglion cells(ipRGCs) express a photopigment,melanopsin,that c...A new mammalian photoreceptor was recently discovered to reside in the ganglion cell layer of the inner retina.These intrinsically photosensitive retinal ganglion cells(ipRGCs) express a photopigment,melanopsin,that confers upon them the ability to respond to light in the absence of all rod and cone photoreceptor input.Although relatively few in number,ipRGCs extend their dendrites across large expanses of the retina making them ideally suited to function as irradiance detectors to assess changes in ambient light levels.Phototransduction in ipRGCs appears to be mediated by transient receptor potential channels more closely resembling the phototransduction cascade of invertebrate rather than vertebrate photoreceptors.ipRGCs convey irradiance information centrally via the optic nerve to influence several functions.ipRGCs are the primary retinal input to the hypothalamic suprachiasmatic nucleus(SCN),a circadian oscillator and biological clock,and this input entrains the SCN to the day/night cycle.ipRGCs contribute irradiance signals that regulate pupil size and they also provide signals that interface with the autonomic nervous system to regulate rhythmic gene activity in major organs of the body.ipRGCs also provide excitatory drive to dopaminergic amacrine cells in the retina,providing a novel basis for the restructuring of retinal circuits by light.Here we review the ground-breaking discoveries,current progress and directions for future investigation.展开更多
Background The exaggerated surge in morning blood pressure （BP） that many patients experience upon awakening may be closely related to target organ damage and may be a predictor of cardiovascular complications. Howe...Background The exaggerated surge in morning blood pressure （BP） that many patients experience upon awakening may be closely related to target organ damage and may be a predictor of cardiovascular complications. However, no previous studies have evaluated the rate of this surge independently of the evening period. It remains unclear whether the rate of increase experienced during the surge is a significant or independent determinant of cardiovascular events. Methods We randomly selected 340 ambulatory BP monitoring （ABPM） patients. All subjects without type 2 diabetes mellitus were divided into two groups： hypertensive group （n=170） and normotensive group （n=170）. We analyzed ambulatory blood pressure recordings using a double logistic curve-fitting procedure to determine whether the magnitude of the surge in BP and heart rate （HR） in the morning is related to the level of BP in hypertensive individuals. We evaluated the association between the rate of the morning surge in systolic BP （SBP） and the incidence of myocardial infarction and stroke in normotensive and hypertensive subjects. Results Comparisons between hypertensive and normotensive subjects showed that the rates of the morning surges in SBP, mean BP （MBP）, and diastolic BP （DBP） were greater in the hypertensive group （P 〈0.05） than in the normotensive group. The rate of morning surge in BP was found to be correlated with the daytime SBP （r=0.236, P 〈0.01）, the difference between the day and night plateau （r=0.249, P 〈0.01）, and the night SBP （r---0.160, P 〈0.05）, respectively. After controlling for age, sex, and mean systolic pressure within 24 hours （24 h SBP）, the rate of morning surge in SBP was closely correlated with daytime SBP （r=0.463, P 〈0.001）, night SBP （r=-0.173, P 〈0.05）, and the difference between the day and night plateau （r=0.267, P 〈0.001）. Logistic regression analysis revealed that the rate of morning surge in SBP was an independent determinant of myocardia展开更多
Dysregulation of circadian rhythms associates with cardiovascular disorders.It is known that deletion of the core circadian gene Bma/1 in mice causes dilated car-diomyopathy.However,the biological rhythm regulation sy...Dysregulation of circadian rhythms associates with cardiovascular disorders.It is known that deletion of the core circadian gene Bma/1 in mice causes dilated car-diomyopathy.However,the biological rhythm regulation system in mouse is very different from that of humans.Whether BMAL1 plays a role in regulating human heart function remains unclear.Here we generated a BMAL1 knockout human embryonic stem cell(hESC)model and further derived human BMAL1 deficient cardiomy-ocytes.We show that BMAL1 deficient hESC-derived cardiomyocytes exhibited typical phenotypes of dilated cardiomyopathy including attenuated contractility,cal-cium dysregulation,and disorganized myofilaments.In addition,mitochondrial fission and mitophagy were suppressed in BMAL1 deficient hESC-cardiomyocytes,which resulted in significantly attenuated mitochondrial oxidative phosphorylation and compromised cardiomy-ocyte function.We also found that BMAL1 binds to the E-box element in the promoter region of BNIP3 gene and specifically controls BNIP3 protein expression.BMAL1 knockout directly reduced BNIP3 protein level,causing compromised mitophagy and mitochondria dysfunction and thereby leading to compromised cardiomyocyte function.Our data indicated that the core circadian gene S/VMLf is critical for normal mitochondria activities and cardiac function.Circadian rhythm disruption may directly link to compromised heart function and dilated cardiomyopathy in humans.展开更多
After three decades of the amazing progress made on molecular studies of plant-microbe interactions(MPMI),we have begun to ask ourselves"what are the major questions still remaining?"as if the puzzle has onl...After three decades of the amazing progress made on molecular studies of plant-microbe interactions(MPMI),we have begun to ask ourselves"what are the major questions still remaining?"as if the puzzle has only a few pieces missing.Such an exercise has ultimately led to the realization that we still have many more questions than answers.Therefore,it would be an impossible task for us to project a coherent"big picture"of the MPMI field in a single review.Instead,we provide our opinions on where we would like to go in our research as an invitation to the community to join us in this exploration of new MPMI frontiers.展开更多
Sleep disorders have a profound and well-documented impact on overall health and quality of life in the general population. In patients with chronic disease, sleep disorders are more prevalent, with an additional morb...Sleep disorders have a profound and well-documented impact on overall health and quality of life in the general population. In patients with chronic disease, sleep disorders are more prevalent, with an additional morbidity and mortality burden. The complex and dynamic relationship between sleep disorders and chronic kidney disease(CKD) remain relatively little investigated. This article presents an overview of sleep disorders in patients with CKD, with emphasis on relevant pathophysiologic underpinnings and clinical presentations. Evidence-based interventions will be discussed, in the context of individual sleep disorders, namely sleep apnea, insomnia, restless leg syndrome and excessive daytime sleepiness. Limitations of the current knowledge as well as future research directions will be highlighted, with a final discussion of different conceptual frameworks of the relationship between sleep disorders and CKD.展开更多
Plants initiate leaf senescence to reallocate energy and nutrients from aging to developing tissues for optimizing growth fitness and reproduction at the end of the growing season or under stress. Jasmonate （JA）, a ...Plants initiate leaf senescence to reallocate energy and nutrients from aging to developing tissues for optimizing growth fitness and reproduction at the end of the growing season or under stress. Jasmonate （JA）, a lipid-derived phytohormone, is known as an important endogenous signal in inducing leaf senescence. However, whether and how the circadian clock gates JA signaling to induce leaf senescence in plants remains elusive. In this study, we show that Evening Complex （EC）, a core component of the circadian oscillator, negatively regulates leaf senescence in Arabidopsis thaliana. Transcriptomic profiling analysis reveals that EC is closely involved in JA signaling and response, consistent with accelerated leaf senescence unanimously displayed by EC mutants upon JA induction. We found that EC directly binds the promoter of MYC2, which encodes a key activator of JA-induced leaf senescence, and represses its expression. Ge- netic analysis further demonstrated that the accelerated JA-induced leaf senescence in EC mutants is abrogated by myc2 myc3 myc4 triple mutation. Collectively, these results reveal a critical molecular mechanism illustrating how the core component of the circadian clock gates JA signaling to regulate leaf senescence.展开更多
Many plants have evolved a drought escape （DE） mechanism to shorten their life cycle when facing water- deficit conditions. While drought tolerance has been intensively investigated, the genetic and molecular mechan...Many plants have evolved a drought escape （DE） mechanism to shorten their life cycle when facing water- deficit conditions. While drought tolerance has been intensively investigated, the genetic and molecular mechanisms of DE remain elusive. In this study, we found that low water-deficit treatment （LWT） at the early stage of rice development can trigger early flowering and reduced tiller numbers. LWT induced the accu- mulation of abscisic acid （ABA）, which in turn has feed-back effects on light perception and circadian clock by synchronously regulating many flowering-related genes to promote early flowering. Moreover, some of light receptors, circadian components, and flowering-related genes including OsTOC1, Ghd7, and PhyB were found to be involved in LWT in an ABA-dependent manner, whereas some of the other flowering- related genes including OsGI, OsELF3, OsPRR37, and OsMADS50 were involved in the regulation of DE independent of ABA. In addition, we found that strigolactones and OsTB1 are involved in the tillering inhibition under LWT, which is independent of the flowering pathway in rice. Taken together, our.findings provide compelling evidence that DE in rice is coordinately regulated by multiple pathways during the reproduction （flowering） switch.展开更多
Improved soybean cultivars have been adapted to grow at a wide range of latitudes,enabling expansion of cultivation worldwide.However,the genetic basis of this broad adaptation is still not clear.Here,we report the id...Improved soybean cultivars have been adapted to grow at a wide range of latitudes,enabling expansion of cultivation worldwide.However,the genetic basis of this broad adaptation is still not clear.Here,we report the identification of GmPRR3b as a major flowering time regulatory gene that has been selected during domestication and genetic improvement for geographic expansion.Through a genome-wide association study of a diverse soybean landrace panel consisting of 279 accessions,we identified 16 candidate quantitative loci associated with flowering time and maturity time.The strongest signal resides in the known flowering gene E2,verifying the effectiveness of our approach.We detected strong signals associated with both flowering and maturity time in a genomic region containing GmPRR3b.Haplotype analysis revealed that GmPRR3bH6 is the major form of GmPRR3b that has been utilized during recent breeding of modern cultivars.mRNA profiling analysis showed that GmPRR3bH6 displays rhythmic and photoperiod-dependent expression and is preferentially induced under long-day conditions.Overexpression of GmPRR3bH6 increased main stem node number and yield,while knockout of GmPRR3bH6 using CRISPR/Cas9 technology delayed growth and the floral transition.GmPRR3bH6 appears to act as a transcriptional repressor of multiple predicted circadian clock genes,including GmCCAIa,which directly upregulates J/GmELF3a to modulate flowering time.The causal SNP(Chr12:5520945)likely endows GmPRR3bH6 a moderate but appropriate level of activity,leading to early flowering and vigorous growth traits preferentially selected during broad adaptation of landraces and improvement of cultivars.展开更多
Circadian mating rhythms, mating frequency, mating duration, and the effect of mating duration on fecundity and fertility in the cabbage beetle, Colaphellus bowringi were investigated in the laboratory. Mating occurre...Circadian mating rhythms, mating frequency, mating duration, and the effect of mating duration on fecundity and fertility in the cabbage beetle, Colaphellus bowringi were investigated in the laboratory. Mating occurred throughout the 24-h cycle but the majority of copulations occurred in the photophase with two apparent peaks, one at 8：00 and another at 16：00. Mating frequency observations for 10 consecutive days indicated that pre-mating period of C. bowringi was about 4 days, and pairs mated an average of 5 times per day and an average of 40 times during the first 10 days. There was a negative correlation between mating frequency and mating duration during the consecutive mating. The mean duration of the first copulation （136.24± 4.62 min） was significantly longer than those of the second （57.87 ± 2.03 min）, third （53.05 ±2.05 min） and fourth copulation （30.86 ± 2.98 min）. Fecundity showed a slight increase with increasing mating duration but no significant difference among treatments. However, fertility was significantly influenced by the mating duration in this species. Mating of 20-min duration did not produce viable eggs. The mean percentage of fertile eggs with completed mating duration （204.43±18.96 min, 56.75% fertile eggs） was significantly higher than those with 60 min （39.55%） and 30 min （17.91%） mating duration, suggesting that the longer mating duration might be associated with transfer of more sperm that are used to increase the fertility of eggs.展开更多
Soybean(Glycine max) is a facultative short-day plant with a sensitive photoperiod perception and reaction system, which allows it to adjust its physiological state and gene regulatory networks to seasonal and diurnal...Soybean(Glycine max) is a facultative short-day plant with a sensitive photoperiod perception and reaction system, which allows it to adjust its physiological state and gene regulatory networks to seasonal and diurnal changes in environmental conditions. In the past few decades, soybean cultivation has spread from East Asia to areas throughout the world. Biologists and breeders must now confront the challenge of understanding the molecular mechanism of soybean photoperiodism and improving agronomic traits to enable this important crop to adapt to geographical and environmental changes. In this review, we summarize the genetic regulatory network underlying photoperiodic responses in soybean. Genomic and genetic studies have revealed that the circadian clock, in conjunction with the light perception pathways, regulates photoperiodic flowering. Here, we provide an annotated list of 844 candidate flowering genes in soybean, with their putative biological functions. Many photoperiod-related genes have been intensively selected during domestication and crop improvement. Finally, we describe recent progress in engineering photoperiod-responsive genes for improving agronomic traits to enhance geographic adaptation in soybean, as well as future prospects for research on soybean photoperiodic responses.展开更多
Acute focal cerebral ischemic stroke(IS)is a leading cause of morbidity and mortality worldwide.Acupuncture is an emerging alternative therapy that has been beneficial to acute brain ischemia.However,the underlying pr...Acute focal cerebral ischemic stroke(IS)is a leading cause of morbidity and mortality worldwide.Acupuncture is an emerging alternative therapy that has been beneficial to acute brain ischemia.However,the underlying protective mechanism of its neuroprotective effect remains unclear.Human original circadian rhythm will be lost after IS,which seriously affects the quality of life and functional recovery of stroke patients.We hypothesize that acupuncture treats IS by regulating the balance of Clock and Bmal1.This study aims to explore the effect of acupuncture at acupoints GV20 and BL23 on neuroprotection and anti-apoptosis in middle cerebral artery occlusion(MCAO)rats and expression of apoptosis and circadian rhythm related proteins.Male Sprague-Dawley(SD)rats were randomly divided into five groups:normal group(Normal),sham model group(Sham MCAO),MCAO model group(MCAO),sham electroacupuncture group(Sham EA)and electroacupuncture group(EA).The MCAO model was prepared by electrocoagulation.The first acupuncture treatment was performed within 2 h after surgery,and then acupuncture therapy was performed on 1st day,2nd day and 3rd day respectively.After their neurological examination at 72 h of ischemia,the rats from each group were sacrificed.Triphenyltetrazolium chloride(TTC)staining was used to evaluate the brain infarct size.Ultrastructural observation on cerebral ischemic cortex and serum inflammatory cytokines were evaluated.TUNEL staining was used to detect cell apoptosis of brain tissue.The expression levels of proteins Bax,bcl-2,caspase-3,Clock and Bmal1 in the cerebral ischemic region were detected by immunofluorescence staining.Here,we presented evidence that EA at GV20 and BL23 could significantly improve the neurological deficit score and infarct size,and alleviate the cell apoptosis of brain tissue.Moreover,acupuncture treatment upregulated the anti-apoptotic Bcl-2/Bax ratio and reversed the upregulation of caspase-3 following 72-h cerebral ischemia.In addition,the expression levels of circadian proteins Cl展开更多
文摘Circadian clocks are endogenous timers that enable plants to synchronize biological processes with daily and seasonal environmental conditions in order to allocate resources during the most beneficial times of day and year. The circadian clock regulates a number of central plant activities, including growth, develop- ment, and reproduction, primarily through controlling a substantial proportion of transcriptional activity and protein function. This review examines the roles that alleles of circadian clock genes have played in domestication and improvement of crop plants. The focus here is on three groups of circadian clock genes essential to clock function in Arabidopsis thaliana： PSEUDO-RESPONSE REGULATORs, GIGANTEA, and the evening complex genes EARL Y FLOWERING 3, EARLY FLOWERING 4, and LUX ARRHYTHMO. Homol- ogous genes from each group underlie quantitative trait loci that have beneficial influences on key agricul- tural traits, especially flowering time but also yield, biomass, and biennial growth habit. Emerging insights into circadian clock regulation of other fundamental plant processes, including responses to abiotic and biotic stresses, are discussed to highlight promising avenues for further crop improvement.
基金This work was supported by National Natural Science Foundation of China Grant 30970172, 863 Project Grant 2012AA10A303, and the Program for New Century Excellent Talents in University.
文摘Heading date is a critical trait that determines cropping seasons and regional adaptability in rice （Oryza sativa）. Research efforts during the last decade have identified some important photoperiod pathway genes that are conserved between Arabidopsis and rice. In this study, we identified a novel gene, Oryza sativa ELF3 （OsELF3）, which is a putative homolog of the ELF3 gene in Arabidopsis thaliana. OsELF3 was required for the control of heading date under long-day conditions. Its Tos17-tagging mutants exhibited a delayed heading date phenotype only under long-day, but not short-day, conditions. OsELF3 was highly expressed in leaf blades, and the OsELF3 protein was localized in the nucleolus. An obvious diurnal rhythm of OsELF3 transcript level was observed, with a trough in the early day and a peak in the late night in wild-type plants. However, this expression pattern was disrupted in oself3 mutants. Further inves- tigations showed that the expression of OsGI and Ghd7 was up-regulated in the oself3 mutant, indicating that OsELF3 acts as a negative regulator upstream of OsGI and Ghd7 in the flowering-time control under long-day conditions. The rhythmic expression of circadian clock-related genes, including some OsPRR members, was obviously affected in oself3 mutants. Our results indicated that OsELF3 acts as a floral activator in the long-day photoperiodic pathway via its cross- talk with the circadian clock in rice.
基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(No.2011-0017449).
文摘To date,most current reports on the development and optimization of artificial lighting sources have focused on the energy performance levels and limited color qualities of white light-emitting diodes(LEDs).However,these properties are insufficient in terms of representing all performance levels required when adjusting white LEDs for healthy and smart lighting.Here,we introduce essential and advanced figures of merit pertaining to circadian performance as well as vision performance and color quality.We compare all possible properties of commercialized artificial lighting,daylight and four-package white LEDs which consist of long-wavelength pass dichroic filter(LPDF)-capped,phosphor-converted red,amber and green LEDs(pc-LEDs)and a blue LED.We show that these tunable four-package white LEDs produce a tunable circadian effect for melatonin suppression/secretion,a high color quality for color perception/reproduction,high efficiency for energy savings and tunable figures of merit for the smart LED lighting market.
基金We acknowledge support by grants from the National Institutes of Health （1R01 GM-114297）, National Science Foundation （MCB- 1543813）, U.S.-Israel Binationat Science Foundation （BSF#2015316） to E.H., and Rural Development Administration, Republic of Korea （P J01104001） to J.-I.K.
文摘PHYTOCHROME-INTERACTING FACTORs （PIFs） are members of the basic helix-loop-helix （bHLH） family of transcription factors in Arabidopsis. Since their discovery in phytochrome-mediated light signaling pathways, recent studies have unraveled new functions of PIFs in integrating multiple signaling pathways not only through their role as transcription factors directly targeting gene expression but also by interacting with diverse groups of factors to optimize plant growth and development. These include endogenous （e.g., hormonal） as well as abiotic （light, circadian, and elevated temperature） and biotic （defense responses） pathways. PIFs interact with key factors in each of these pathways and tailor the outcome of the signal integration among these pathways. This review discusses the roles of PIFs as pivotal signal integrators in regulating plant growth and development.
基金supported by National Institutes of Health Grants (No.DK096784 to Jessica M.Ferrell and Nos.DK44442 and DK58379 to John Y.L.Chiang)
文摘Mounting research evidence demonstrates a significant negative impact of circadian disruption on human health. Shift work, chronic jet lag and sleep disturbances are associated with increased incidence of metabolic syndrome, and consequently result in obesity, type 2 diabetes and dyslipidemia.Here, these associations are reviewed with respect to liver metabolism and disease.
文摘Sleep disorders have become a global issue,and discovering their causes and consequences are the focus of many research endeavors.An estimated 70 million Americans suffer from some form of sleep disorder.Certain sleep disorders have been shown to cause neurocognitive impairment such as decreased cognitive ability,slower response times and performance detriments.Recent research suggests that individuals with sleep abnormalities are also at greater risk of serious adverse health,economic consequences,and most importantly increased all-cause mortality.Several research studies support the associations among sleep,immune function and inflammation.Here,we review the current research linking sleep,immune function,and gastrointestinal diseases and discuss the interdependent relationship between sleep and these gastrointestinal disorders.Different physiologic processes including immune system and inflammatory cytokines help regulate the sleep.The inflammatory cytokines such as tumor necrosis factor,interleukin-1(IL-1),and IL-6 have been shown to be a significant contributor of sleep disturbances.On the other hand,sleep disturbances such as sleep deprivation have been shown to up regulate these inflammatory cytokines.Alterations in these cytokine levels have been demonstrated in certain gastrointestinal diseases such as inflammatory bowel disease,gastro-esophageal reflux,liver disorders and colorectal cancer.In turn,abnormal sleep brought on by these diseases is shown to contribute to the severity of these same gastrointestinal diseases.Knowledge of these relationships will allow gastroenterologists a great opportunity to enhance the care of their patients.
基金supported by grants from the National Institutes of Health, the National Institute of Neurological Disorders and Stroke R01 NS035615the National Eye Institute R01 EY017809
文摘A new mammalian photoreceptor was recently discovered to reside in the ganglion cell layer of the inner retina.These intrinsically photosensitive retinal ganglion cells(ipRGCs) express a photopigment,melanopsin,that confers upon them the ability to respond to light in the absence of all rod and cone photoreceptor input.Although relatively few in number,ipRGCs extend their dendrites across large expanses of the retina making them ideally suited to function as irradiance detectors to assess changes in ambient light levels.Phototransduction in ipRGCs appears to be mediated by transient receptor potential channels more closely resembling the phototransduction cascade of invertebrate rather than vertebrate photoreceptors.ipRGCs convey irradiance information centrally via the optic nerve to influence several functions.ipRGCs are the primary retinal input to the hypothalamic suprachiasmatic nucleus(SCN),a circadian oscillator and biological clock,and this input entrains the SCN to the day/night cycle.ipRGCs contribute irradiance signals that regulate pupil size and they also provide signals that interface with the autonomic nervous system to regulate rhythmic gene activity in major organs of the body.ipRGCs also provide excitatory drive to dopaminergic amacrine cells in the retina,providing a novel basis for the restructuring of retinal circuits by light.Here we review the ground-breaking discoveries,current progress and directions for future investigation.
文摘Background The exaggerated surge in morning blood pressure （BP） that many patients experience upon awakening may be closely related to target organ damage and may be a predictor of cardiovascular complications. However, no previous studies have evaluated the rate of this surge independently of the evening period. It remains unclear whether the rate of increase experienced during the surge is a significant or independent determinant of cardiovascular events. Methods We randomly selected 340 ambulatory BP monitoring （ABPM） patients. All subjects without type 2 diabetes mellitus were divided into two groups： hypertensive group （n=170） and normotensive group （n=170）. We analyzed ambulatory blood pressure recordings using a double logistic curve-fitting procedure to determine whether the magnitude of the surge in BP and heart rate （HR） in the morning is related to the level of BP in hypertensive individuals. We evaluated the association between the rate of the morning surge in systolic BP （SBP） and the incidence of myocardial infarction and stroke in normotensive and hypertensive subjects. Results Comparisons between hypertensive and normotensive subjects showed that the rates of the morning surges in SBP, mean BP （MBP）, and diastolic BP （DBP） were greater in the hypertensive group （P 〈0.05） than in the normotensive group. The rate of morning surge in BP was found to be correlated with the daytime SBP （r=0.236, P 〈0.01）, the difference between the day and night plateau （r=0.249, P 〈0.01）, and the night SBP （r---0.160, P 〈0.05）, respectively. After controlling for age, sex, and mean systolic pressure within 24 hours （24 h SBP）, the rate of morning surge in SBP was closely correlated with daytime SBP （r=0.463, P 〈0.001）, night SBP （r=-0.173, P 〈0.05）, and the difference between the day and night plateau （r=0.267, P 〈0.001）. Logistic regression analysis revealed that the rate of morning surge in SBP was an independent determinant of myocardia
基金This work was supported by the National Natural Science Foundation of China(NSFC No.81322003,No.31571527,N.S.No.31501098,Q.L.,No.81500241,C.X.,No.81870600,C.L.,No-81570771 and 31871189,RZ.Q.)+1 种基金the Science and Technology Commission of Shanghai Municipality(No.17XD1400300,No.17JC1400200)the National Key R&D Program of China 2018YFC2000202,and the Haiju program of National Children’s Medical Center EK1125180102.We apologize to people whose work was relevant to but not cited in this study due to limited space。
文摘Dysregulation of circadian rhythms associates with cardiovascular disorders.It is known that deletion of the core circadian gene Bma/1 in mice causes dilated car-diomyopathy.However,the biological rhythm regulation system in mouse is very different from that of humans.Whether BMAL1 plays a role in regulating human heart function remains unclear.Here we generated a BMAL1 knockout human embryonic stem cell(hESC)model and further derived human BMAL1 deficient cardiomy-ocytes.We show that BMAL1 deficient hESC-derived cardiomyocytes exhibited typical phenotypes of dilated cardiomyopathy including attenuated contractility,cal-cium dysregulation,and disorganized myofilaments.In addition,mitochondrial fission and mitophagy were suppressed in BMAL1 deficient hESC-cardiomyocytes,which resulted in significantly attenuated mitochondrial oxidative phosphorylation and compromised cardiomy-ocyte function.We also found that BMAL1 binds to the E-box element in the promoter region of BNIP3 gene and specifically controls BNIP3 protein expression.BMAL1 knockout directly reduced BNIP3 protein level,causing compromised mitophagy and mitochondria dysfunction and thereby leading to compromised cardiomyocyte function.Our data indicated that the core circadian gene S/VMLf is critical for normal mitochondria activities and cardiac function.Circadian rhythm disruption may directly link to compromised heart function and dilated cardiomyopathy in humans.
基金grants from the National Institutes of Health(NIH 1R35GM118036)National Science Foundation(IOS 1645589)+5 种基金Howard Hughes Medical Institute to X.D.,grants from the NIH(NIH 1R35GM136402)National Science Foundation(NSF 1937855-0)United States Department of Agriculture(USDA,2019-70016-2979)G.C.,a grant from National Natural Science Foundation of China(31830019)J.-M.Z.,and a grant from National Natural Science Foundation of China(31922075)Youth Innovation Promotion Association of the Chinese Academy of Sciences to J.Z.
文摘After three decades of the amazing progress made on molecular studies of plant-microbe interactions(MPMI),we have begun to ask ourselves"what are the major questions still remaining?"as if the puzzle has only a few pieces missing.Such an exercise has ultimately led to the realization that we still have many more questions than answers.Therefore,it would be an impossible task for us to project a coherent"big picture"of the MPMI field in a single review.Instead,we provide our opinions on where we would like to go in our research as an invitation to the community to join us in this exploration of new MPMI frontiers.
基金Supported by a NIH grant to Dr.Cukor(MD006875)(in part)
文摘Sleep disorders have a profound and well-documented impact on overall health and quality of life in the general population. In patients with chronic disease, sleep disorders are more prevalent, with an additional morbidity and mortality burden. The complex and dynamic relationship between sleep disorders and chronic kidney disease(CKD) remain relatively little investigated. This article presents an overview of sleep disorders in patients with CKD, with emphasis on relevant pathophysiologic underpinnings and clinical presentations. Evidence-based interventions will be discussed, in the context of individual sleep disorders, namely sleep apnea, insomnia, restless leg syndrome and excessive daytime sleepiness. Limitations of the current knowledge as well as future research directions will be highlighted, with a final discussion of different conceptual frameworks of the relationship between sleep disorders and CKD.
文摘Plants initiate leaf senescence to reallocate energy and nutrients from aging to developing tissues for optimizing growth fitness and reproduction at the end of the growing season or under stress. Jasmonate （JA）, a lipid-derived phytohormone, is known as an important endogenous signal in inducing leaf senescence. However, whether and how the circadian clock gates JA signaling to induce leaf senescence in plants remains elusive. In this study, we show that Evening Complex （EC）, a core component of the circadian oscillator, negatively regulates leaf senescence in Arabidopsis thaliana. Transcriptomic profiling analysis reveals that EC is closely involved in JA signaling and response, consistent with accelerated leaf senescence unanimously displayed by EC mutants upon JA induction. We found that EC directly binds the promoter of MYC2, which encodes a key activator of JA-induced leaf senescence, and represses its expression. Ge- netic analysis further demonstrated that the accelerated JA-induced leaf senescence in EC mutants is abrogated by myc2 myc3 myc4 triple mutation. Collectively, these results reveal a critical molecular mechanism illustrating how the core component of the circadian clock gates JA signaling to regulate leaf senescence.
文摘Many plants have evolved a drought escape （DE） mechanism to shorten their life cycle when facing water- deficit conditions. While drought tolerance has been intensively investigated, the genetic and molecular mechanisms of DE remain elusive. In this study, we found that low water-deficit treatment （LWT） at the early stage of rice development can trigger early flowering and reduced tiller numbers. LWT induced the accu- mulation of abscisic acid （ABA）, which in turn has feed-back effects on light perception and circadian clock by synchronously regulating many flowering-related genes to promote early flowering. Moreover, some of light receptors, circadian components, and flowering-related genes including OsTOC1, Ghd7, and PhyB were found to be involved in LWT in an ABA-dependent manner, whereas some of the other flowering- related genes including OsGI, OsELF3, OsPRR37, and OsMADS50 were involved in the regulation of DE independent of ABA. In addition, we found that strigolactones and OsTB1 are involved in the tillering inhibition under LWT, which is independent of the flowering pathway in rice. Taken together, our.findings provide compelling evidence that DE in rice is coordinately regulated by multiple pathways during the reproduction （flowering） switch.
基金the National Key Research and Development Plan(2016YFD0101005,2016YFD0100201,and 2016YFD0100304)the National Natural Science Foundation of China(31871705 and 31422041)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences,and the Central Public-Interest Scientific Institution Basal Research Fund(Y2016JC13).
文摘Improved soybean cultivars have been adapted to grow at a wide range of latitudes,enabling expansion of cultivation worldwide.However,the genetic basis of this broad adaptation is still not clear.Here,we report the identification of GmPRR3b as a major flowering time regulatory gene that has been selected during domestication and genetic improvement for geographic expansion.Through a genome-wide association study of a diverse soybean landrace panel consisting of 279 accessions,we identified 16 candidate quantitative loci associated with flowering time and maturity time.The strongest signal resides in the known flowering gene E2,verifying the effectiveness of our approach.We detected strong signals associated with both flowering and maturity time in a genomic region containing GmPRR3b.Haplotype analysis revealed that GmPRR3bH6 is the major form of GmPRR3b that has been utilized during recent breeding of modern cultivars.mRNA profiling analysis showed that GmPRR3bH6 displays rhythmic and photoperiod-dependent expression and is preferentially induced under long-day conditions.Overexpression of GmPRR3bH6 increased main stem node number and yield,while knockout of GmPRR3bH6 using CRISPR/Cas9 technology delayed growth and the floral transition.GmPRR3bH6 appears to act as a transcriptional repressor of multiple predicted circadian clock genes,including GmCCAIa,which directly upregulates J/GmELF3a to modulate flowering time.The causal SNP(Chr12:5520945)likely endows GmPRR3bH6 a moderate but appropriate level of activity,leading to early flowering and vigorous growth traits preferentially selected during broad adaptation of landraces and improvement of cultivars.
基金The research was supported by a grant from National Natural Science Foundation of China （30460074）. We also thank three anonymous reviewers for their valuable comments.
文摘Circadian mating rhythms, mating frequency, mating duration, and the effect of mating duration on fecundity and fertility in the cabbage beetle, Colaphellus bowringi were investigated in the laboratory. Mating occurred throughout the 24-h cycle but the majority of copulations occurred in the photophase with two apparent peaks, one at 8：00 and another at 16：00. Mating frequency observations for 10 consecutive days indicated that pre-mating period of C. bowringi was about 4 days, and pairs mated an average of 5 times per day and an average of 40 times during the first 10 days. There was a negative correlation between mating frequency and mating duration during the consecutive mating. The mean duration of the first copulation （136.24± 4.62 min） was significantly longer than those of the second （57.87 ± 2.03 min）, third （53.05 ±2.05 min） and fourth copulation （30.86 ± 2.98 min）. Fecundity showed a slight increase with increasing mating duration but no significant difference among treatments. However, fertility was significantly influenced by the mating duration in this species. Mating of 20-min duration did not produce viable eggs. The mean percentage of fertile eggs with completed mating duration （204.43±18.96 min, 56.75% fertile eggs） was significantly higher than those with 60 min （39.55%） and 30 min （17.91%） mating duration, suggesting that the longer mating duration might be associated with transfer of more sperm that are used to increase the fertility of eggs.
基金supported by the National Key Research and Development Plan(2016YFD0101005)National Natural Science Foundation of China(31422041)+1 种基金China Postdoctoral Science Foundation Grant(2014M56013)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences
文摘Soybean(Glycine max) is a facultative short-day plant with a sensitive photoperiod perception and reaction system, which allows it to adjust its physiological state and gene regulatory networks to seasonal and diurnal changes in environmental conditions. In the past few decades, soybean cultivation has spread from East Asia to areas throughout the world. Biologists and breeders must now confront the challenge of understanding the molecular mechanism of soybean photoperiodism and improving agronomic traits to enable this important crop to adapt to geographical and environmental changes. In this review, we summarize the genetic regulatory network underlying photoperiodic responses in soybean. Genomic and genetic studies have revealed that the circadian clock, in conjunction with the light perception pathways, regulates photoperiodic flowering. Here, we provide an annotated list of 844 candidate flowering genes in soybean, with their putative biological functions. Many photoperiod-related genes have been intensively selected during domestication and crop improvement. Finally, we describe recent progress in engineering photoperiod-responsive genes for improving agronomic traits to enhance geographic adaptation in soybean, as well as future prospects for research on soybean photoperiodic responses.
基金This study was supported by the Foundation of Hubei Provincal Department of Education of China(No.B2018098).
文摘Acute focal cerebral ischemic stroke(IS)is a leading cause of morbidity and mortality worldwide.Acupuncture is an emerging alternative therapy that has been beneficial to acute brain ischemia.However,the underlying protective mechanism of its neuroprotective effect remains unclear.Human original circadian rhythm will be lost after IS,which seriously affects the quality of life and functional recovery of stroke patients.We hypothesize that acupuncture treats IS by regulating the balance of Clock and Bmal1.This study aims to explore the effect of acupuncture at acupoints GV20 and BL23 on neuroprotection and anti-apoptosis in middle cerebral artery occlusion(MCAO)rats and expression of apoptosis and circadian rhythm related proteins.Male Sprague-Dawley(SD)rats were randomly divided into five groups:normal group(Normal),sham model group(Sham MCAO),MCAO model group(MCAO),sham electroacupuncture group(Sham EA)and electroacupuncture group(EA).The MCAO model was prepared by electrocoagulation.The first acupuncture treatment was performed within 2 h after surgery,and then acupuncture therapy was performed on 1st day,2nd day and 3rd day respectively.After their neurological examination at 72 h of ischemia,the rats from each group were sacrificed.Triphenyltetrazolium chloride(TTC)staining was used to evaluate the brain infarct size.Ultrastructural observation on cerebral ischemic cortex and serum inflammatory cytokines were evaluated.TUNEL staining was used to detect cell apoptosis of brain tissue.The expression levels of proteins Bax,bcl-2,caspase-3,Clock and Bmal1 in the cerebral ischemic region were detected by immunofluorescence staining.Here,we presented evidence that EA at GV20 and BL23 could significantly improve the neurological deficit score and infarct size,and alleviate the cell apoptosis of brain tissue.Moreover,acupuncture treatment upregulated the anti-apoptotic Bcl-2/Bax ratio and reversed the upregulation of caspase-3 following 72-h cerebral ischemia.In addition,the expression levels of circadian proteins Cl
