第26届CIE大会于2007年7月份在中国北京召开。CIE第4分部是交通运输照明与光信号(LIGHTING AND SIGNALLING FOR TRANSPORT)分部,本文对CIE大会第4分部的报告情况进行了总结,并根据CIE大会道路照明研究的最新进展及我国道路照明的现状,...第26届CIE大会于2007年7月份在中国北京召开。CIE第4分部是交通运输照明与光信号(LIGHTING AND SIGNALLING FOR TRANSPORT)分部,本文对CIE大会第4分部的报告情况进行了总结,并根据CIE大会道路照明研究的最新进展及我国道路照明的现状,对我国道路照明与交通信号的发展给出了指导性意见,并且进行了展望。展开更多
Sessile plants have developed a very delicate system to sense diverse kinds of endogenous developmental cues and exogenous environmental stimuli by using a simple Ca^2＋ ion. Calmodulin （CAM） is the predominant Ca^2...Sessile plants have developed a very delicate system to sense diverse kinds of endogenous developmental cues and exogenous environmental stimuli by using a simple Ca^2＋ ion. Calmodulin （CAM） is the predominant Ca^2＋ sensor and plays a crucial role in decoding the Ca^2＋ signatures into proper cellular responses in various cellular compartments in eukaryotes. A growing body of evidence points to the importance of Ca^2＋ and CaM in the regulation of the transcriptional process during plant responses to endogenous and exogenous stimuli. Here, we review recent progress in the identification of transcriptional regulators modulated by Ca^2＋ and CaM and in the assessment of their functional significance during plant signal transduction in response to biotic and abiotic stresses and developmental cues.展开更多
As an essential plant macronutrient, the low availability of phosphorus （P） in most soils imposes serious limitation on crop production. Plants have evolved complex responsive and adaptive mechanisms for acquisition...As an essential plant macronutrient, the low availability of phosphorus （P） in most soils imposes serious limitation on crop production. Plants have evolved complex responsive and adaptive mechanisms for acquisition, remobilization and recycling of phosphate （Pi） to maintain P homeostasis. Spatio-temporal molecular, physiological, and biochemical Pi deficiency responses developed by plants are the consequence of local and systemic sensing and signaling pathways. Pi deficiency is sensed locally by the root system where hormones serve as important signaling components in terms of developmental reprogramming, leading to changes in root system architecture. Root-to-shoot and shoot-to-root signals, delivered through the xylem and phloem, respectively, involving Pi itself, hormones, miRNAs, mRNAs, and sucrose, serve to coordinate Pi deficiency responses at the whole-plant level. A combination of chromatin remodeling, transcriptional and posttranslational events contribute to globally regulating a wide range of Pi deficiency responses. In this review, recent advances are evaluated in terms of progress toward developing a comprehen- sive understanding of the molecular events underlying control over P homeostasis. Application of this knowledge, in terms of developing crop plants having enhanced attributes for P use efficiency, is discussed from the perspective of agricultural sustainability in the face of diminishing global P supplies.展开更多
Calcium-dependent protein kinases （CDPKs） comprise a family of plant serine/threonine protein kinases in which the calcium sensing domain and the kinase effector domain are combined within one molecule. So far, a bi...Calcium-dependent protein kinases （CDPKs） comprise a family of plant serine/threonine protein kinases in which the calcium sensing domain and the kinase effector domain are combined within one molecule. So far, a biological function in abiotic stress signaling has only been reported for few CDPK isoforms, whereas the underlying biochemical mechanism for these CDPKs is still mainly unknown. Here, we show that CPK21 from Arabidopsis thaliana is biochemically activated in vivo in response to hyperosmotic stress. Loss-of-function seedlings of cpk21 are more tolerant to hyperosmotic stress and mutant plants show increased stress responses with respect to marker gene expression and metabolite accumulation. In transgenic Arabidopsis complementation lines in the cpk21 mutant background, in which either CPK21 wildtype, or a full-length enzyme variant carrying an amino-acid substitution were stably expressed, stress responsitivity was restored by CPK21 but not with the kinase inactive variant. The biochemical characterization of in planta synthesized and purified CPK21 protein revealed that within the calcium-binding domain, N-terminal EF1- and EF2-motifs compared to C-terminal EF3- and EF4-motifs differ in their contribution to calcium-regulated kinase activity, suggesting a crucial role for the N-terminal EF-hand pair. Our data provide evidence for CPK21 contributing in abiotic stress signaling and suggest that the N-terminal EF-hand pair is a calcium-sensing determinant controlling specificity of CPK21 function.展开更多
Potassium （K＋） is an essential macronutrient in plants and a lack of K＋ significantly reduces the potential for plant growth and development. By contrast, sodium （Na＋）, while beneficial to some extent, at high ...Potassium （K＋） is an essential macronutrient in plants and a lack of K＋ significantly reduces the potential for plant growth and development. By contrast, sodium （Na＋）, while beneficial to some extent, at high concentrations it disturbs and inhibits various physiological processes and plant growth. Due to their chemical similarities, some functions of K＋ can be undertaken by Na＋ but K＋ homeostasis is severely affected by salt stress, on the other hand. Recent advances have highlighted the fascinating regulatory mechanisms of K＋ and Na＋ transport and signaling in plants. This review summarizes three major topics： （i） the transport mechanisms of K＋ and Na＋ from the soil to the shoot and to the cellular - compartments; （ii） the mechanisms through which plants sense and respond to K＋ and Na＋ availability; and （iii） the components involved in maintenance of K＋/Na＋ homeostasis in plants under salt stress.展开更多
Vanishing bile duct syndromes （VBDS） are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from li...Vanishing bile duct syndromes （VBDS） are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from liver failure. The majority of adult patients with VBDS suffer from primary biliary cirrhosis （PBC） and primary sclerosing cholangitis （PSC）. Ursodeoxycholic acid （UDCA）, a hydrophilic dihydroxy bile acid, is the only drug currently approved for the treatment of patients with PBC, and anticholestatic effects have been reported for several other cholestatic syndromes. Several potential mechanisms of action of UDCA have been proposed including stimulation of hepatobiliary secretion, inhibition of apoptosis and protection of cholangiocytes against toxic effects of hydrophobic bile acids.展开更多
Recent studies have demonstrated that chloroplasts and mitochondria evoke specific Ca2＋ signals in response to biotic and abiotic stresses in a stress-dependent manner. The identification of Ca2＋ transporters and Ca...Recent studies have demonstrated that chloroplasts and mitochondria evoke specific Ca2＋ signals in response to biotic and abiotic stresses in a stress-dependent manner. The identification of Ca2＋ transporters and Ca2＋signaling mol- ecules in chloroplasts and mitochondria implies that they play roles in controlling not only intra-organellar functions, but also extra-organellar processes such as plant immunity and stress responses. It appears that organellar Ca2＋ signaling might be more important to plant cell functions than previously thought. This review briefly summarizes what is known about the molecular basis of Ca2＋ signaling in plant mitochondria and chloroplasts.展开更多
采用示踪技术探索了3 H JA的运输和分配规律及其受伤害胁迫的影响。外源 3 H JA能够在小麦幼苗体内向上和向下运输 ,局部灼伤其运输与分配都发生了改变。从小麦根系饲喂的3 H JA ,在植株内的分布量依序为根 >茎 >叶 ,时间较长 (4h...采用示踪技术探索了3 H JA的运输和分配规律及其受伤害胁迫的影响。外源 3 H JA能够在小麦幼苗体内向上和向下运输 ,局部灼伤其运输与分配都发生了改变。从小麦根系饲喂的3 H JA ,在植株内的分布量依序为根 >茎 >叶 ,时间较长 (4h)时分配于心叶的3 H JA大大增加。当叶片受到局部灼伤时3 H JA向地上部的输出量减少 ;但局部灼伤可加快由心叶饲喂的3 H JA的向下运输 ,改变3 H JA在小麦幼苗各部位的分配比率。心叶饲喂短时间 (5min)时 ,3 H JA主要积累在受到伤胁迫的展开叶 (第 2叶 )中。向展开叶 (第2叶 )饲喂的3 H JA向下运输的速率高于向上运输的速率。展开更多
Ethylene participates in the regulation of numerous cellular events and biological processes, including wa- ter loss, during leaf and flower petal wilting. The diverse ethylene responses may be regulated via dynamic i...Ethylene participates in the regulation of numerous cellular events and biological processes, including wa- ter loss, during leaf and flower petal wilting. The diverse ethylene responses may be regulated via dynamic interplays between protein phosphorylation/dephosphorylation and ubiquitin/26S proteasome-mediated protein degradation and protease cleavage. To address how ethylene alters protein phosphorylation through multi-furcated signaling pathways, we performed a lSN stable isotope labelling-based, differential, and quantitative phosphoproteomics study on air- and ethylene-treated ethylene-insensitive Arabidopsis double loss-of-function mutant ein3-1/eill-1. Among 535 non-redundant phosphopeptides identified, two and four phosphopeptides were up- and downregulated by ethylene, respectively. Ethylene- regulated phosphorylation of aquaporin PIP2;1 is positively correlated with the water flux rate and water loss in leaf. Genetic studies in combination with quantitative proteomics, immunoblot analysis, protoplast swelling/shrinking experiments, and leaf water loss assays on the transgenic plants expressing both the wild-type and S280A/S283A-mutated PIP2;1 in the both Col-O and ein3eill genetic backgrounds suggest that ethylene increases water transport rate in Arabidopsis cells by enhancing S280/S283 phosphorylation at the C terminus of PIP2;1. Unknown kinase and/or phosphatase activities may participate in the initial up- regulation independent of the cellular functions of EIN3/EIL1. This finding contributes to our understanding of ethylene-regulated leaf wilting that is commonly observed during post-harvest storage of plant organs.展开更多
Lorentz curve fittings are applied to frequency distributions of the concentrations of O3, CO, NOx and SO2 recorded at the Jinsha regional atmospheric background station （JSH） from June 2006 to July 2007, and the pe...Lorentz curve fittings are applied to frequency distributions of the concentrations of O3, CO, NOx and SO2 recorded at the Jinsha regional atmospheric background station （JSH） from June 2006 to July 2007, and the peak concentrations of these species for the different seasons are obtained. The peak concentrations are considered to be representative of different background levels for certain processes. The peak concentrations are compared with the corresponding mean （median） concentrations, and the suitability and limitations of the mean （median） values as the background levels are discussed. The mean （median） values might represent the background concentrations in the region under some circumstances, but in other cases these values often underestimate or overestimate the true background concentrations owing to the transport of pollutants and other factors. The effects of air masses transported from different regions on the pollutant background concentrations are obtained by analyzing the 72-hour backward trajectories of air masses 100m above the ground at JSH, These trajectories are estimated using the HYSPLIT model and then clustered for the measurement period. The spatial distribution and seasonal variations of trajectories and the corresponding mean concentrations of O3, SO〉 NOx and CO for different clusters are analyzed. After filtering the seasonal changes in pollutant concentrations, the relative influences of air masses from different regions are obtained. The results show that JSH can be used to obtain the atmospheric background information of different air masses originating from or passing over the Yangtze River Delta, Central South China and the Jianghan Plain. Air masses from Central China, South China, and the western Yangtze River Delta contribute significantly to O3 at JSH. Air masses from the north and northeast of JSH （i.e., the Jianghan Plain, Huang-Huai Plain and North China Plain） and the south （Central South China） contribute significantly to SO2, CO and NOx concentra展开更多
Calcium acts as a second messenger for signaling to a variety of stimuli including MAMPs （Microbe-Associated Molecular Patterns）, such as fig22 and elf18 that are derived from bacterial flagellin and elongation fact...Calcium acts as a second messenger for signaling to a variety of stimuli including MAMPs （Microbe-Associated Molecular Patterns）, such as fig22 and elf18 that are derived from bacterial flagellin and elongation factor Tu, respectively. Here, Arabidopsis thaliana mutants with changed calcium elevation （cce） in response to fig22 treatment were isolated and characterized. Besides novel mutant alleles of the fig22 receptor, FLS2 （Flagellin-Sensitive 2）, and the receptor-associated kinase, BAK1 （Brassinosteroid receptor 1-Associated Kinase 1）, the new cce mutants can be categorized into two main groups--those with a reduced or an enhanced calcium elevation. Moreover, cce mutants from both groups show differ- ential phenotypes to different sets of MAMPs. Thus, these mutants will facilitate the discovery of novel components in early MAMP signaling and bridge the gaps in current knowledge of calcium signaling during plant-microbe interactions. Last but not least, the screening method is optimized for speed （covering 384 plants in 3 or 10 h） and can be adapted to genetically dissect any other stimuli that induce a change in calcium levels.展开更多
Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins ...Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins belong to the homeodomain(HD)-containing transcription factor family.They play vital roles in the regulation of morphogenesis.NKX1-2 is one member of the NKX subfamily.At present,information about its nuclear localization signal(NLS)sequence is limited.We studied the NLS sequence of zebrafish Nkx1.2 by introducing sequence changes such as deletion,mutation,and truncation,and identified an NLS motif(QNRRTKWKKQ)that is localized at the C-terminus of the homeodomain.Moreover,the deletion of two amino acid residues(RR)in this NLS motif prevents Nkx1.2 from entering the nucleus,indicating that the two amino acids are essential for Nkx1.2 nuclear localization.However,the NLS motif alone is unable to target cytoplasmic protein glutathione S-transferase(GST)to the nucleus.An intact homeodomain is necessary for mediating the complete nuclear transport of cytoplasmic protein.Unlike most nuclear import proteins with short NLS sequences,a long NLS is present in zebrafish Nkx1.2.We also demonstrated that the sequences of homeodomain of NKX1.2 are well conserved among different species.This study is informative to verify the function of the NKX1.2 protein.展开更多
文摘第26届CIE大会于2007年7月份在中国北京召开。CIE第4分部是交通运输照明与光信号(LIGHTING AND SIGNALLING FOR TRANSPORT)分部,本文对CIE大会第4分部的报告情况进行了总结,并根据CIE大会道路照明研究的最新进展及我国道路照明的现状,对我国道路照明与交通信号的发展给出了指导性意见,并且进行了展望。
文摘Sessile plants have developed a very delicate system to sense diverse kinds of endogenous developmental cues and exogenous environmental stimuli by using a simple Ca^2＋ ion. Calmodulin （CAM） is the predominant Ca^2＋ sensor and plays a crucial role in decoding the Ca^2＋ signatures into proper cellular responses in various cellular compartments in eukaryotes. A growing body of evidence points to the importance of Ca^2＋ and CaM in the regulation of the transcriptional process during plant responses to endogenous and exogenous stimuli. Here, we review recent progress in the identification of transcriptional regulators modulated by Ca^2＋ and CaM and in the assessment of their functional significance during plant signal transduction in response to biotic and abiotic stresses and developmental cues.
基金supported by grants from the United States Department of AgricultureNational Institute of Food and Agriculture (NIFA 201015479+2 种基金 W.J.L.)the National Natural Science Foundation of China (31025022 H.L.)
文摘As an essential plant macronutrient, the low availability of phosphorus （P） in most soils imposes serious limitation on crop production. Plants have evolved complex responsive and adaptive mechanisms for acquisition, remobilization and recycling of phosphate （Pi） to maintain P homeostasis. Spatio-temporal molecular, physiological, and biochemical Pi deficiency responses developed by plants are the consequence of local and systemic sensing and signaling pathways. Pi deficiency is sensed locally by the root system where hormones serve as important signaling components in terms of developmental reprogramming, leading to changes in root system architecture. Root-to-shoot and shoot-to-root signals, delivered through the xylem and phloem, respectively, involving Pi itself, hormones, miRNAs, mRNAs, and sucrose, serve to coordinate Pi deficiency responses at the whole-plant level. A combination of chromatin remodeling, transcriptional and posttranslational events contribute to globally regulating a wide range of Pi deficiency responses. In this review, recent advances are evaluated in terms of progress toward developing a comprehen- sive understanding of the molecular events underlying control over P homeostasis. Application of this knowledge, in terms of developing crop plants having enhanced attributes for P use efficiency, is discussed from the perspective of agricultural sustainability in the face of diminishing global P supplies.
文摘Calcium-dependent protein kinases （CDPKs） comprise a family of plant serine/threonine protein kinases in which the calcium sensing domain and the kinase effector domain are combined within one molecule. So far, a biological function in abiotic stress signaling has only been reported for few CDPK isoforms, whereas the underlying biochemical mechanism for these CDPKs is still mainly unknown. Here, we show that CPK21 from Arabidopsis thaliana is biochemically activated in vivo in response to hyperosmotic stress. Loss-of-function seedlings of cpk21 are more tolerant to hyperosmotic stress and mutant plants show increased stress responses with respect to marker gene expression and metabolite accumulation. In transgenic Arabidopsis complementation lines in the cpk21 mutant background, in which either CPK21 wildtype, or a full-length enzyme variant carrying an amino-acid substitution were stably expressed, stress responsitivity was restored by CPK21 but not with the kinase inactive variant. The biochemical characterization of in planta synthesized and purified CPK21 protein revealed that within the calcium-binding domain, N-terminal EF1- and EF2-motifs compared to C-terminal EF3- and EF4-motifs differ in their contribution to calcium-regulated kinase activity, suggesting a crucial role for the N-terminal EF-hand pair. Our data provide evidence for CPK21 contributing in abiotic stress signaling and suggest that the N-terminal EF-hand pair is a calcium-sensing determinant controlling specificity of CPK21 function.
文摘Potassium （K＋） is an essential macronutrient in plants and a lack of K＋ significantly reduces the potential for plant growth and development. By contrast, sodium （Na＋）, while beneficial to some extent, at high concentrations it disturbs and inhibits various physiological processes and plant growth. Due to their chemical similarities, some functions of K＋ can be undertaken by Na＋ but K＋ homeostasis is severely affected by salt stress, on the other hand. Recent advances have highlighted the fascinating regulatory mechanisms of K＋ and Na＋ transport and signaling in plants. This review summarizes three major topics： （i） the transport mechanisms of K＋ and Na＋ from the soil to the shoot and to the cellular - compartments; （ii） the mechanisms through which plants sense and respond to K＋ and Na＋ availability; and （iii） the components involved in maintenance of K＋/Na＋ homeostasis in plants under salt stress.
文摘Vanishing bile duct syndromes （VBDS） are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from liver failure. The majority of adult patients with VBDS suffer from primary biliary cirrhosis （PBC） and primary sclerosing cholangitis （PSC）. Ursodeoxycholic acid （UDCA）, a hydrophilic dihydroxy bile acid, is the only drug currently approved for the treatment of patients with PBC, and anticholestatic effects have been reported for several other cholestatic syndromes. Several potential mechanisms of action of UDCA have been proposed including stimulation of hepatobiliary secretion, inhibition of apoptosis and protection of cholangiocytes against toxic effects of hydrophobic bile acids.
文摘Recent studies have demonstrated that chloroplasts and mitochondria evoke specific Ca2＋ signals in response to biotic and abiotic stresses in a stress-dependent manner. The identification of Ca2＋ transporters and Ca2＋signaling mol- ecules in chloroplasts and mitochondria implies that they play roles in controlling not only intra-organellar functions, but also extra-organellar processes such as plant immunity and stress responses. It appears that organellar Ca2＋ signaling might be more important to plant cell functions than previously thought. This review briefly summarizes what is known about the molecular basis of Ca2＋ signaling in plant mitochondria and chloroplasts.
文摘采用示踪技术探索了3 H JA的运输和分配规律及其受伤害胁迫的影响。外源 3 H JA能够在小麦幼苗体内向上和向下运输 ,局部灼伤其运输与分配都发生了改变。从小麦根系饲喂的3 H JA ,在植株内的分布量依序为根 >茎 >叶 ,时间较长 (4h)时分配于心叶的3 H JA大大增加。当叶片受到局部灼伤时3 H JA向地上部的输出量减少 ;但局部灼伤可加快由心叶饲喂的3 H JA的向下运输 ,改变3 H JA在小麦幼苗各部位的分配比率。心叶饲喂短时间 (5min)时 ,3 H JA主要积累在受到伤胁迫的展开叶 (第 2叶 )中。向展开叶 (第2叶 )饲喂的3 H JA向下运输的速率高于向上运输的速率。
文摘Ethylene participates in the regulation of numerous cellular events and biological processes, including wa- ter loss, during leaf and flower petal wilting. The diverse ethylene responses may be regulated via dynamic interplays between protein phosphorylation/dephosphorylation and ubiquitin/26S proteasome-mediated protein degradation and protease cleavage. To address how ethylene alters protein phosphorylation through multi-furcated signaling pathways, we performed a lSN stable isotope labelling-based, differential, and quantitative phosphoproteomics study on air- and ethylene-treated ethylene-insensitive Arabidopsis double loss-of-function mutant ein3-1/eill-1. Among 535 non-redundant phosphopeptides identified, two and four phosphopeptides were up- and downregulated by ethylene, respectively. Ethylene- regulated phosphorylation of aquaporin PIP2;1 is positively correlated with the water flux rate and water loss in leaf. Genetic studies in combination with quantitative proteomics, immunoblot analysis, protoplast swelling/shrinking experiments, and leaf water loss assays on the transgenic plants expressing both the wild-type and S280A/S283A-mutated PIP2;1 in the both Col-O and ein3eill genetic backgrounds suggest that ethylene increases water transport rate in Arabidopsis cells by enhancing S280/S283 phosphorylation at the C terminus of PIP2;1. Unknown kinase and/or phosphatase activities may participate in the initial up- regulation independent of the cellular functions of EIN3/EIL1. This finding contributes to our understanding of ethylene-regulated leaf wilting that is commonly observed during post-harvest storage of plant organs.
基金supported by National Basic Research Program of China (Grant No. 2005CB4222002)Project of China Meteorological Administration (Grant No. GYHY[QX]200706005)National Natural Science Foundation of China (Grant No. 40705042)
文摘Lorentz curve fittings are applied to frequency distributions of the concentrations of O3, CO, NOx and SO2 recorded at the Jinsha regional atmospheric background station （JSH） from June 2006 to July 2007, and the peak concentrations of these species for the different seasons are obtained. The peak concentrations are considered to be representative of different background levels for certain processes. The peak concentrations are compared with the corresponding mean （median） concentrations, and the suitability and limitations of the mean （median） values as the background levels are discussed. The mean （median） values might represent the background concentrations in the region under some circumstances, but in other cases these values often underestimate or overestimate the true background concentrations owing to the transport of pollutants and other factors. The effects of air masses transported from different regions on the pollutant background concentrations are obtained by analyzing the 72-hour backward trajectories of air masses 100m above the ground at JSH, These trajectories are estimated using the HYSPLIT model and then clustered for the measurement period. The spatial distribution and seasonal variations of trajectories and the corresponding mean concentrations of O3, SO〉 NOx and CO for different clusters are analyzed. After filtering the seasonal changes in pollutant concentrations, the relative influences of air masses from different regions are obtained. The results show that JSH can be used to obtain the atmospheric background information of different air masses originating from or passing over the Yangtze River Delta, Central South China and the Jianghan Plain. Air masses from Central China, South China, and the western Yangtze River Delta contribute significantly to O3 at JSH. Air masses from the north and northeast of JSH （i.e., the Jianghan Plain, Huang-Huai Plain and North China Plain） and the south （Central South China） contribute significantly to SO2, CO and NOx concentra
基金This work was supported by a Deutsche Forschungsgemeinschaft (DFG) grant，financed by the DFG grant，by the Swiss National Science Foundation grant
文摘Calcium acts as a second messenger for signaling to a variety of stimuli including MAMPs （Microbe-Associated Molecular Patterns）, such as fig22 and elf18 that are derived from bacterial flagellin and elongation factor Tu, respectively. Here, Arabidopsis thaliana mutants with changed calcium elevation （cce） in response to fig22 treatment were isolated and characterized. Besides novel mutant alleles of the fig22 receptor, FLS2 （Flagellin-Sensitive 2）, and the receptor-associated kinase, BAK1 （Brassinosteroid receptor 1-Associated Kinase 1）, the new cce mutants can be categorized into two main groups--those with a reduced or an enhanced calcium elevation. Moreover, cce mutants from both groups show differ- ential phenotypes to different sets of MAMPs. Thus, these mutants will facilitate the discovery of novel components in early MAMP signaling and bridge the gaps in current knowledge of calcium signaling during plant-microbe interactions. Last but not least, the screening method is optimized for speed （covering 384 plants in 3 or 10 h） and can be adapted to genetically dissect any other stimuli that induce a change in calcium levels.
基金Supported by the National Natural Science Foundation of China(No.31970429)the Shandong Provincial Natural Science Foundation(No.ZR 2022 MC 032)。
文摘Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins belong to the homeodomain(HD)-containing transcription factor family.They play vital roles in the regulation of morphogenesis.NKX1-2 is one member of the NKX subfamily.At present,information about its nuclear localization signal(NLS)sequence is limited.We studied the NLS sequence of zebrafish Nkx1.2 by introducing sequence changes such as deletion,mutation,and truncation,and identified an NLS motif(QNRRTKWKKQ)that is localized at the C-terminus of the homeodomain.Moreover,the deletion of two amino acid residues(RR)in this NLS motif prevents Nkx1.2 from entering the nucleus,indicating that the two amino acids are essential for Nkx1.2 nuclear localization.However,the NLS motif alone is unable to target cytoplasmic protein glutathione S-transferase(GST)to the nucleus.An intact homeodomain is necessary for mediating the complete nuclear transport of cytoplasmic protein.Unlike most nuclear import proteins with short NLS sequences,a long NLS is present in zebrafish Nkx1.2.We also demonstrated that the sequences of homeodomain of NKX1.2 are well conserved among different species.This study is informative to verify the function of the NKX1.2 protein.
