As sessile organisms, plants encounter a variety of environmental stresses and must optimize their growth for survival. Abscisic acid （ABA） and cytokinin antagonistically regulate many developmental processes and en...As sessile organisms, plants encounter a variety of environmental stresses and must optimize their growth for survival. Abscisic acid （ABA） and cytokinin antagonistically regulate many developmental processes and environmental stress responses in plants. However, the molecular mechanism underlying this antag- onism remains poorly defined. In this study, we demonstrated that Sucrose nonfermentingl-related kinases SnRK2.2, SnRK2.3, and SnRK2.6, the key kinases of the ABA signaling pathway, directly interact with and phosphorylate type-A response regulator 5 （ARR5）, a negative regulator of cytokinin signaling. The phosphorylation of ARR5 Ser residues by SnRK2s enhanced ARR5 protein stability. Accord- ingly, plants overexpressing ARR5 showed ABA hypersensitivity and drought tolerance, and these pheno- types could not be recapitulated by overexpressing a non-phosphorylated ARR5 mimic. Moreover, the type-B ARRs, ARR1, ARR11 and ARR12, physically interacted with SnRK2s and repressed the kinase activ- ity of SnRK2.6. The arrl, 11,12 triple mutant exhibited hypersensitivity to ABA. Genetic analysis demon- strated that SnRK2s act upstream of ARR5 but downstream of ARR1, ARR11 and ARR12 in mediating ABA response and drought tolerance. Taken together, this study unravels the antagonistic actions of several molecular components of the ABA and cytokinin signaling pathways in mediates drought stress response, providing significant insights into how plants coordinate growth and drought stress response by integrating multiple hormone pathways.展开更多
Type-B monoamine oxidase inhibitors,encompassing selegiline,rasagiline,and safinamide,are available to treat Parkinson's disease.These drugs ameliorate motor symptoms and improve motor fluctuation in the advanced ...Type-B monoamine oxidase inhibitors,encompassing selegiline,rasagiline,and safinamide,are available to treat Parkinson's disease.These drugs ameliorate motor symptoms and improve motor fluctuation in the advanced stages of the disease.There is also evidence suppo rting the benefit of type-B monoamine oxidase inhibitors on non-motor symptoms of Parkinson's disease,such as mood deflection,cognitive impairment,sleep disturbances,and fatigue.Preclinical studies indicate that type-B monoamine oxidase inhibitors hold a strong neuroprotective potential in Parkinson's disease and other neurodegenerative diseases for reducing oxidative stress and stimulating the production and release of neurotrophic factors,particularly glial cell line-derived neurotrophic factor,which suppo rt dopaminergic neurons.Besides,safinamide may interfere with neurodegenerative mechanisms,countera cting excessive glutamate overdrive in basal ganglia motor circuit and reducing death from excitotoxicity.Due to the dual mechanism of action,the new generation of type-B monoamine oxidase inhibitors,including safinamide,is gaining interest in other neurological pathologies,and many supporting preclinical studies are now available.The potential fields of application concern epilepsy,Duchenne muscular dystrophy,multiple scle rosis,and above all,ischemic brain injury.The purpose of this review is to investigate the preclinical and clinical pharmacology of selegiline,rasagiline,and safinamide in Parkinson's disease and beyond,focusing on possible future therapeutic applications.展开更多
Soil salinity severely limits crop yields and quality.Plants have evolved several strategies to mitigate the adverse effects of salinity,including redistribution and compartmentalization of toxic ions using ion-specif...Soil salinity severely limits crop yields and quality.Plants have evolved several strategies to mitigate the adverse effects of salinity,including redistribution and compartmentalization of toxic ions using ion-specific transporters.However,the mechanisms underlying the regulation of these ion transporters have not been fully elucidated.Loss-of-function mutants of OsHKT2;1,which is involved in sodium uptake,exhibit strong salt stress-resistant phenotypes.In this study,OsHKT2;1 was identified as a transcriptional target of the type-B response regulator OsRR22.Loss-of-function osrr22 mutants showed resilience to salt stress,and OsRR22-overexpression plants were sensitive to salt stress.OsRR22 was found to activate the expression of OsHKT2;1 by directly binding to the promoter region of OsHKT2;1 via a consensus cis-element of type-B response regulators.Moreover,rice DELLA protein OsSLR1 directly interacted with OsRR22 and functioned as a transcriptional co-activator.This study has uncovered a novel transcriptional regulatory mechanism by which a type-B response regulator controls sodium transport under salinity stress.展开更多
Numerical simulations based on a high-resolution three-dimensional MIT general circulation model(MITgcm)using realistic topography and tidal forcing are conducted to investigate the generation and propagation of the s...Numerical simulations based on a high-resolution three-dimensional MIT general circulation model(MITgcm)using realistic topography and tidal forcing are conducted to investigate the generation and propagation of the so-called type-a waves(large-amplitude rank-ordered wave packets)and type-b waves(isolated wave packets)in the northern South China Sea.At first,we summarized and analyzed the generation and propagation characteristics of these waves.Then,energy budget at the Luzon Strait is calculated.Energy generation has three local maxima every day,of which the largest one corresponds to the emergence of the type-a wave.Energy flux at the west boundary of the Luzon Strait shows two local maxima each day.The larger one is consistent with the generation of the type-a wave and the smaller one is in correspondence with the generation of the type-b wave.Sensitivity experiments are designed to explore the role of the east and west ridge of the Luzon Strait on the generation and propagation of the type-a and type-b waves.It is found that the east ridge is indispensable on the generation of the type-a wave while the west ridge has little contribution.The west ridge diminishes the type-a waves'amplitude but hardly changes their propagation speed.The type-b waves also come from perturbation signals which originate from the east ridge and are enhanced in amplitude and reduced in propagation speed by the west ridge.展开更多
The Type-B authentic response regulator(ARR-Bs)gene family is one of the important plant-specific transcription factor families involved in variety of physiological processes.However,study of ARR-Bs gene family in soy...The Type-B authentic response regulator(ARR-Bs)gene family is one of the important plant-specific transcription factor families involved in variety of physiological processes.However,study of ARR-Bs gene family in soybean is limited.Genome-wide analysis and expression profiling of the ARR-Bs gene family were performed in the soybean genome.31 ARR-Bs genes(namely GmARR-B1-31)were identified,containing conserved catalytic domains with protein lengths and molecular weights ranging from 246 to 699 amino acids(aa)and 28.30 to 76.86 kDa,respectively.Phylogenetic analysis grouped ARR-Bs genes into three clusters—Cluster I,Cluster II,and Cluster III—which included 15,12,and 4 genes,respectively,and were asymmetrically distributed on 17 chromosomes.Tissue specific expression analysis of GmARR-Bs family revealed a high transcription level in flowers,roots and seeds.The subcellular localization of GmARR5,GmARR14 were observed in the nucleus,and the promoter region of them included low-temperature responsive element(LTR),the C-repeat/dehydration responsive element(DRE),MBS,ABRE,MYB,MEJA and TCA-elements,which possibly participate in abiotic stress and hormones responses.qRTPCR analysis showed that the expression of GmARR-B genes were affected by different abiotic stresses,especially cold stress and salt stress,and GmARR-B5 and GmARR-B14 were significantly induced by cold stress.This suggested that ARR-Bs genes were involved in multiple abiotic stress response pathways and acted as a positive factor under cold stress.展开更多
文摘As sessile organisms, plants encounter a variety of environmental stresses and must optimize their growth for survival. Abscisic acid （ABA） and cytokinin antagonistically regulate many developmental processes and environmental stress responses in plants. However, the molecular mechanism underlying this antag- onism remains poorly defined. In this study, we demonstrated that Sucrose nonfermentingl-related kinases SnRK2.2, SnRK2.3, and SnRK2.6, the key kinases of the ABA signaling pathway, directly interact with and phosphorylate type-A response regulator 5 （ARR5）, a negative regulator of cytokinin signaling. The phosphorylation of ARR5 Ser residues by SnRK2s enhanced ARR5 protein stability. Accord- ingly, plants overexpressing ARR5 showed ABA hypersensitivity and drought tolerance, and these pheno- types could not be recapitulated by overexpressing a non-phosphorylated ARR5 mimic. Moreover, the type-B ARRs, ARR1, ARR11 and ARR12, physically interacted with SnRK2s and repressed the kinase activ- ity of SnRK2.6. The arrl, 11,12 triple mutant exhibited hypersensitivity to ABA. Genetic analysis demon- strated that SnRK2s act upstream of ARR5 but downstream of ARR1, ARR11 and ARR12 in mediating ABA response and drought tolerance. Taken together, this study unravels the antagonistic actions of several molecular components of the ABA and cytokinin signaling pathways in mediates drought stress response, providing significant insights into how plants coordinate growth and drought stress response by integrating multiple hormone pathways.
文摘Type-B monoamine oxidase inhibitors,encompassing selegiline,rasagiline,and safinamide,are available to treat Parkinson's disease.These drugs ameliorate motor symptoms and improve motor fluctuation in the advanced stages of the disease.There is also evidence suppo rting the benefit of type-B monoamine oxidase inhibitors on non-motor symptoms of Parkinson's disease,such as mood deflection,cognitive impairment,sleep disturbances,and fatigue.Preclinical studies indicate that type-B monoamine oxidase inhibitors hold a strong neuroprotective potential in Parkinson's disease and other neurodegenerative diseases for reducing oxidative stress and stimulating the production and release of neurotrophic factors,particularly glial cell line-derived neurotrophic factor,which suppo rt dopaminergic neurons.Besides,safinamide may interfere with neurodegenerative mechanisms,countera cting excessive glutamate overdrive in basal ganglia motor circuit and reducing death from excitotoxicity.Due to the dual mechanism of action,the new generation of type-B monoamine oxidase inhibitors,including safinamide,is gaining interest in other neurological pathologies,and many supporting preclinical studies are now available.The potential fields of application concern epilepsy,Duchenne muscular dystrophy,multiple scle rosis,and above all,ischemic brain injury.The purpose of this review is to investigate the preclinical and clinical pharmacology of selegiline,rasagiline,and safinamide in Parkinson's disease and beyond,focusing on possible future therapeutic applications.
基金supported by the National Natural Science Foundation of China (32001448,32272027)。
文摘Soil salinity severely limits crop yields and quality.Plants have evolved several strategies to mitigate the adverse effects of salinity,including redistribution and compartmentalization of toxic ions using ion-specific transporters.However,the mechanisms underlying the regulation of these ion transporters have not been fully elucidated.Loss-of-function mutants of OsHKT2;1,which is involved in sodium uptake,exhibit strong salt stress-resistant phenotypes.In this study,OsHKT2;1 was identified as a transcriptional target of the type-B response regulator OsRR22.Loss-of-function osrr22 mutants showed resilience to salt stress,and OsRR22-overexpression plants were sensitive to salt stress.OsRR22 was found to activate the expression of OsHKT2;1 by directly binding to the promoter region of OsHKT2;1 via a consensus cis-element of type-B response regulators.Moreover,rice DELLA protein OsSLR1 directly interacted with OsRR22 and functioned as a transcriptional co-activator.This study has uncovered a novel transcriptional regulatory mechanism by which a type-B response regulator controls sodium transport under salinity stress.
基金The National Key Research and Development Plan of China under contract No.2016YFC1401300the National Natural Science Foundation of China under contract No.41276008the Taishan Scholars Program
文摘Numerical simulations based on a high-resolution three-dimensional MIT general circulation model(MITgcm)using realistic topography and tidal forcing are conducted to investigate the generation and propagation of the so-called type-a waves(large-amplitude rank-ordered wave packets)and type-b waves(isolated wave packets)in the northern South China Sea.At first,we summarized and analyzed the generation and propagation characteristics of these waves.Then,energy budget at the Luzon Strait is calculated.Energy generation has three local maxima every day,of which the largest one corresponds to the emergence of the type-a wave.Energy flux at the west boundary of the Luzon Strait shows two local maxima each day.The larger one is consistent with the generation of the type-a wave and the smaller one is in correspondence with the generation of the type-b wave.Sensitivity experiments are designed to explore the role of the east and west ridge of the Luzon Strait on the generation and propagation of the type-a and type-b waves.It is found that the east ridge is indispensable on the generation of the type-a wave while the west ridge has little contribution.The west ridge diminishes the type-a waves'amplitude but hardly changes their propagation speed.The type-b waves also come from perturbation signals which originate from the east ridge and are enhanced in amplitude and reduced in propagation speed by the west ridge.
基金This work was financially supported by the National Modern Agricultural Industrial Technology System(CARS-04-01A).
文摘The Type-B authentic response regulator(ARR-Bs)gene family is one of the important plant-specific transcription factor families involved in variety of physiological processes.However,study of ARR-Bs gene family in soybean is limited.Genome-wide analysis and expression profiling of the ARR-Bs gene family were performed in the soybean genome.31 ARR-Bs genes(namely GmARR-B1-31)were identified,containing conserved catalytic domains with protein lengths and molecular weights ranging from 246 to 699 amino acids(aa)and 28.30 to 76.86 kDa,respectively.Phylogenetic analysis grouped ARR-Bs genes into three clusters—Cluster I,Cluster II,and Cluster III—which included 15,12,and 4 genes,respectively,and were asymmetrically distributed on 17 chromosomes.Tissue specific expression analysis of GmARR-Bs family revealed a high transcription level in flowers,roots and seeds.The subcellular localization of GmARR5,GmARR14 were observed in the nucleus,and the promoter region of them included low-temperature responsive element(LTR),the C-repeat/dehydration responsive element(DRE),MBS,ABRE,MYB,MEJA and TCA-elements,which possibly participate in abiotic stress and hormones responses.qRTPCR analysis showed that the expression of GmARR-B genes were affected by different abiotic stresses,especially cold stress and salt stress,and GmARR-B5 and GmARR-B14 were significantly induced by cold stress.This suggested that ARR-Bs genes were involved in multiple abiotic stress response pathways and acted as a positive factor under cold stress.
