Leaf-color mutations are a widely-observed class of mutations, playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure, function, genetics and development. A naturally-occurr...Leaf-color mutations are a widely-observed class of mutations, playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure, function, genetics and development. A naturally-occurring leaf-color rice mutant, Baihuaidao 7, was analyzed. Mutant plants typically exhibited a green-white-green leaf-color progression, but this phenotype was only expressed in the presence of a stress signal induced by mechanical scarification such as transplantation. Prior to the appearance of white ~eaves, mutant plant growth, leaf color, chlorophyll content, and chloroplast ultrastructure appeared to be identical to those of the wild type. After the changeover to white leaf color, an examination of the mutated leaves revealed a decrease in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoid content, a reduction in the number of chloroplast grana lamella and grana, and a gradual degradation of the thylakoid lamellas. At maturity, the mutant plant was etiolated and dwarfed compared with wild-type plants. Genetic analysis indicated that the leaf mutant character is controlled by a recessive nuclear gene. Genetic mapping of the mutant gene was performed using an F2 population derived from a Baihuaidao 7 ~ Jiangxi 1587 cross. The mutant gene was mapped to rice chromosome 11, positioned between InDel markers L59.2-7 and L64.8-11, which are separated by approximately 740.5 kb. The mutant gene is believed to be a new leaf-color mutant gene in rice, and is tentatively designated as gwgl.展开更多
The soil-borne necrotrophic fungus Rhizoctonia solani is one of destructive fungi causing severe yield losses in various important crops. However, the host defense mechanisms against the invasion of this pathogen are ...The soil-borne necrotrophic fungus Rhizoctonia solani is one of destructive fungi causing severe yield losses in various important crops. However, the host defense mechanisms against the invasion of this pathogen are poorly understood. In this study, we employed an i TRAQ-based quantitative proteomic approach to investigate host proteins responsive to R. solani using the resistant rice cultivar YSBR1. As a whole, we identified 319 differentially accumulated proteins(DAPs) after inoculation of rice plants with R. solani. Functional categorization analysis indicates that these DAPs cover a broad range of functions. Notably, a substantial portion of the DAPs are involved in cell redox homeostasis, carbohydrate metabolism, and phenylpropanoid biosynthesis, or belong to pathogenesis-related proteins, indicating that these processes/proteins play important roles in host defense against R. solani. Interestingly, all of the DAPs involved in photosynthesis and chlorophyll biosynthetic processes, and part of the DAPs involved in phenylpropanoid biosynthesis, show reduced accumulation after R. solani infection, suggesting that R. solani probably inhibits host photosynthetic system and phenylpropanoid biosynthesis to facilitate infection and colonization. In conclusion, our results provide both valuable resources and new insights into the molecular mechanisms underlying rice and R. solani interaction.展开更多
Rice resistance to sheath blight （SB） is controlled by polygenes or quantitative trait loci （QTLs） and affected by plant morphological traits, qSB-9^TQ and TAG1^TQ, which control SB resistance and tiller angle （T...Rice resistance to sheath blight （SB） is controlled by polygenes or quantitative trait loci （QTLs） and affected by plant morphological traits, qSB-9^TQ and TAG1^TQ, which control SB resistance and tiller angle （TA）, respectively, were employed to test whether the combination of the two genes will further improve rice SB resistance and reduce yield loss rather than only one of them or neither. Using two pairs of near isogenic lines （NILs）, TAC1^TQ was confirmed to contribute to SB resistance. However, its effect was less considerable than that of qSB-9^TQ. Subsequently, the two genes were introduced into two commercial rice varieties to develop a series of NILs. The NILs carrying both TAG1^TQ and qSB-9^TQ showed more resistance than the NILs containing only one of them. Comparing the grain yield per plant （GYP） under the three different SB disease conditions, namely slight, moderate and severe conditions, NILs carrying both genes apparently lost lower GYP than the NILs without the two genes and the NILs carrying only TAC1^TQ. Under slight disease condition, no significant differences were found on morphology, development and GYP associated traits except for TA between the NILs carrying both genes and either of them, indicating that the two genes have no inferior effect on rice agronomic traits. Results indicated that mAC1^TQ and qSB-9^TQ have high breeding potential, and pyramiding SB resistance QTL and morphological trait QTL is a potential approach in improving rice SB resistance.展开更多
The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on th...The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on the main culm of Yanhui 559 was always 4-5 leaves more than that of Lemont, and the leafing rate of Yanhui 559 was significantly higher than that of Lemont based on similar growth durations from sowing to heading. Furthermore, the difference of the leafing rate was significant at the vegetative growth stage, but not distinctive at the panicle initiation stage. Genetic analysis of the leafing rates in the two backcross populations of Yanhui 559 and Lemont showed that major and quantitative genes controlled the expression of rapid leafing character. Based on results of investigation for some plants with similar growth durations in the backcrossing populations, the rapid leafing genotypes exhibited earlier tillering and more tiller numbers per plant, and its yield components including the number of panicles per plant and number of grains per panicle were superior to those of the slow leafing genotypes. Further research and application feasibility of the rapid leafing genotype in breeding were discussed.展开更多
Narrow genetic background is a key limiting factor in breeding stable high-yielding rice. The introduction and utilization of international rice core germplasm is an important way to increase the genetic diversity of ...Narrow genetic background is a key limiting factor in breeding stable high-yielding rice. The introduction and utilization of international rice core germplasm is an important way to increase the genetic diversity of domestic rice varieties. We conducted a genome-wide association study on 5 panicle traits of 315 rice accessions introduced from the international rice micro-core germplasm bank. Based on the tests from Yangzhou of China and Arkansas of American, environment exhibited a significant impacts on panicle length and primary branch number, while grain length, grain width and grain length/width ratio were insensitive to environment changes. We discovered a total of 7, 5, 10, 8 and 6 chromosomal regions or single nucleotide polymorphism marker loci that were significantly associated with primary branch number, panicle length, grain length, grain width and grain length/width ratio, respectively. Among them, eleven regions were associated with grain shape and one region associated with primary branch number, showing the good consistence in two different environments. Significant linear correlation was discovered between the average trait value and the number of favorable alleles carried by the varieties in all associated loci. Among the associated loci, varieties in aromatic and tropical japonica sub-groups possessed most favorable alleles, while those in temperate japonica sub-group contained the least. The domestic varieties mainly harbored unfavorable alleles in six of the associated loci being detected. On the contrary, 15 varieties from 11 different countries harbored more favorable alleles （as many as 30 or more） than the others. Remarkably, all these 15 varieties belonged to the tropical japonica sub-group. In conclusion, our study demonstrates that varieties in the tropical japonica sub-group had high potentials for breeding stable high-yielding rice. Based on this discovery, we proposed a new approach for improving the panicle traits of domestic rice by using tropical japonica varieties.展开更多
By using a heated molecular beam in combination with a time-of-flight mass spectrometer, we experimentally study the ionization of vibrational-hot carbon disulfide（CS2） molecules irradiated by a linearly polarized 8...By using a heated molecular beam in combination with a time-of-flight mass spectrometer, we experimentally study the ionization of vibrational-hot carbon disulfide（CS2） molecules irradiated by a linearly polarized 800-nm 50-fs strong laser field. The ion yields are measured in a laser intensity range of 7.0 × 10^（12） W/cm^2–1.5 × 10^（14） W/cm^2 at different molecular temperatures of up to 1400 K. Enhanced ionization yield is observed for vibrationally excited CS2 molecules.The results show that the enhancement decreases as the laser intensity increases, and exhibits non-monotonical dependence on the molecular temperature. According to the calculated potential energy curves of the neutral and ionic electronic states of CS2, as well as the theoretical models of molecular strong-field ionization available in the literature, we discuss the mechanism of the enhanced ionization of vibrational-hot molecules. It is indicated that the enhanced ionization could be attributed to both the reduced ionization potential with vibrational excitation and the Frank–Condon factors between the neutral and ionic electronic states. Our study paves the way to understanding the effect of nuclear motion on the strongfield ionization of molecules, which would give a further insight into theoretical and experimental investigations on the interaction of polyatomic molecules with strong laser fields.展开更多
Cuticular wax plays an important role in protecting plants against water loss and pathogen infection and in the adaptations to environmental stresses. The genetic mechanism of the biosynthesis and accumulation of epic...Cuticular wax plays an important role in protecting plants against water loss and pathogen infection and in the adaptations to environmental stresses. The genetic mechanism of the biosynthesis and accumulation of epicuticular wax in rice remains largely unknown. Here, we show a spontaneous mutant displaying wax crystal-sparse leaves and decreased content of epicuticular wax that was derived from the cytoplasmic male sterility （CMS） restorer line Zhenhui 714. Compared with the wild type Zhenhui 714, the mutant exhibited hydrophilic features on leaf surface and more sensitivity to drought stress. The mutation also caused lower grain number per panicle and thousand grain weight, leading to the decline of yield. Genetic analysis indicates that the mutation is controlled by a single recessive gene, named wax crystal-sparse leaf3 （wsl3）. Using segregation populations derived from crosses of mutant/Zhendao 88 and mutant/Wuyujing 3, respectively, the wsl3 gene was fine-mapped to a 110-kb region between markers c3-16 and c3-22 on chromosome 3. According to the rice reference genome and gene analysis, we conclude that a novel gene/mechanism involved in regulation of rice cuticular wax formation.展开更多
设计了一台以增强型氮化镓(eGaN)高电子迁移率晶体管(HEMT)为开关器件的450 W DC/DC模块电源。主功率电路采用同步整流Buck+软开关推挽的两级结构。针对eGaN HEMT应用中的驱动回路寄生电感的影响和驱动印制电路板(PCB)设计改善、开关管...设计了一台以增强型氮化镓(eGaN)高电子迁移率晶体管(HEMT)为开关器件的450 W DC/DC模块电源。主功率电路采用同步整流Buck+软开关推挽的两级结构。针对eGaN HEMT应用中的驱动回路寄生电感的影响和驱动印制电路板(PCB)设计改善、开关管死区时间对软开关效果的影响和优化、eGaN HEMT主电路多层PCB布局等关键设计进行了介绍。最后,搭建八层板结构的样机,实测效率可达95%,证明了设计的合理性。展开更多
目的了解湖北恩施地区和武汉地区手足口病(hand,foot and mouth disease,HFMD)病原体肠道病毒71型(EV-A71)VP1的基因特征。方法收集2010年来自于恩施地区和武汉地区的78例HFMD患儿的咽拭子标本。通过标本接种病毒易感Vero细胞,对产生明...目的了解湖北恩施地区和武汉地区手足口病(hand,foot and mouth disease,HFMD)病原体肠道病毒71型(EV-A71)VP1的基因特征。方法收集2010年来自于恩施地区和武汉地区的78例HFMD患儿的咽拭子标本。通过标本接种病毒易感Vero细胞,对产生明显细胞病变效应的阳性标本进行初筛。利用PCR法对初筛阳性标本进行进一步鉴定,对阳性毒株VP1基因序列进行扩增,将其构建到pMD18-T载体上,最后对VP1全长序列进行测序。通过构建系统进化树分析2010年湖北恩施地区和武汉地区EV-A71病毒株的基因型,并分析探讨其与2010年中国大陆其他地区EV-A71病毒株之间的进化关系。结果从78例手足口病标本中分离得到9株EV-A71,进一步对其VP1序列进行系统进化分析发现所有EV-A71分离株均属于C4亚型。2010年恩施地区和武汉地区EV-A71病毒株与2010年中国大陆其他地区EV-A71病毒株在同一进化分支。本研究中分离自伴随震颤患者的EV-A71病毒株(wh64-CHN-10)的VP1-240位点氨基酸残基为丙氨酸,而其余分离自轻症手足口病患者的8株EV-A71病毒株的VP1-240位点为苏氨酸。结论 EV-A71是2010-2011年恩施和武汉地区手足口病的重要病原体之一,属于C4基因型,VP1-240位点的氨基酸可能影响EV-A71的毒力。展开更多
基金supported by the Natural ScienceFoundation of Jiangsu Province of China (Grant No.SBK2010294)an Open Project Program of Jiangsu Key Laboratory of the Ministry of Education for Plant Functional Genomics (Grant No. K10001)
文摘Leaf-color mutations are a widely-observed class of mutations, playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure, function, genetics and development. A naturally-occurring leaf-color rice mutant, Baihuaidao 7, was analyzed. Mutant plants typically exhibited a green-white-green leaf-color progression, but this phenotype was only expressed in the presence of a stress signal induced by mechanical scarification such as transplantation. Prior to the appearance of white ~eaves, mutant plant growth, leaf color, chlorophyll content, and chloroplast ultrastructure appeared to be identical to those of the wild type. After the changeover to white leaf color, an examination of the mutated leaves revealed a decrease in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoid content, a reduction in the number of chloroplast grana lamella and grana, and a gradual degradation of the thylakoid lamellas. At maturity, the mutant plant was etiolated and dwarfed compared with wild-type plants. Genetic analysis indicated that the leaf mutant character is controlled by a recessive nuclear gene. Genetic mapping of the mutant gene was performed using an F2 population derived from a Baihuaidao 7 ~ Jiangxi 1587 cross. The mutant gene was mapped to rice chromosome 11, positioned between InDel markers L59.2-7 and L64.8-11, which are separated by approximately 740.5 kb. The mutant gene is believed to be a new leaf-color mutant gene in rice, and is tentatively designated as gwgl.
基金financially supported by grants from the National Key Research and Development Program of China(2016YFD0100601)the National Natural Science Foundation of China(31701057 and 31672013)+5 种基金the Natural Science Foundation of Jiangsu Province,China(BK20170487)the Fok Ying Tung Education Foundation,China(151026)the China Postdoctoral Science Foundation(2017M620227)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(19KJD210001)2018 Annual Key Project of Scientific Research in Yangzhou Polytechnic College,China(2018ZR07)。
文摘The soil-borne necrotrophic fungus Rhizoctonia solani is one of destructive fungi causing severe yield losses in various important crops. However, the host defense mechanisms against the invasion of this pathogen are poorly understood. In this study, we employed an i TRAQ-based quantitative proteomic approach to investigate host proteins responsive to R. solani using the resistant rice cultivar YSBR1. As a whole, we identified 319 differentially accumulated proteins(DAPs) after inoculation of rice plants with R. solani. Functional categorization analysis indicates that these DAPs cover a broad range of functions. Notably, a substantial portion of the DAPs are involved in cell redox homeostasis, carbohydrate metabolism, and phenylpropanoid biosynthesis, or belong to pathogenesis-related proteins, indicating that these processes/proteins play important roles in host defense against R. solani. Interestingly, all of the DAPs involved in photosynthesis and chlorophyll biosynthetic processes, and part of the DAPs involved in phenylpropanoid biosynthesis, show reduced accumulation after R. solani infection, suggesting that R. solani probably inhibits host photosynthetic system and phenylpropanoid biosynthesis to facilitate infection and colonization. In conclusion, our results provide both valuable resources and new insights into the molecular mechanisms underlying rice and R. solani interaction.
基金supported by the Key Project of National Science foundation of Jiangsu Higher Education Institutions, China (Grant No. 14KJA210003)the National Transgenic Projects (Grant No. 2014ZX08001-003B)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), China
文摘Rice resistance to sheath blight （SB） is controlled by polygenes or quantitative trait loci （QTLs） and affected by plant morphological traits, qSB-9^TQ and TAG1^TQ, which control SB resistance and tiller angle （TA）, respectively, were employed to test whether the combination of the two genes will further improve rice SB resistance and reduce yield loss rather than only one of them or neither. Using two pairs of near isogenic lines （NILs）, TAC1^TQ was confirmed to contribute to SB resistance. However, its effect was less considerable than that of qSB-9^TQ. Subsequently, the two genes were introduced into two commercial rice varieties to develop a series of NILs. The NILs carrying both TAG1^TQ and qSB-9^TQ showed more resistance than the NILs containing only one of them. Comparing the grain yield per plant （GYP） under the three different SB disease conditions, namely slight, moderate and severe conditions, NILs carrying both genes apparently lost lower GYP than the NILs without the two genes and the NILs carrying only TAC1^TQ. Under slight disease condition, no significant differences were found on morphology, development and GYP associated traits except for TA between the NILs carrying both genes and either of them, indicating that the two genes have no inferior effect on rice agronomic traits. Results indicated that mAC1^TQ and qSB-9^TQ have high breeding potential, and pyramiding SB resistance QTL and morphological trait QTL is a potential approach in improving rice SB resistance.
文摘The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on the main culm of Yanhui 559 was always 4-5 leaves more than that of Lemont, and the leafing rate of Yanhui 559 was significantly higher than that of Lemont based on similar growth durations from sowing to heading. Furthermore, the difference of the leafing rate was significant at the vegetative growth stage, but not distinctive at the panicle initiation stage. Genetic analysis of the leafing rates in the two backcross populations of Yanhui 559 and Lemont showed that major and quantitative genes controlled the expression of rapid leafing character. Based on results of investigation for some plants with similar growth durations in the backcrossing populations, the rapid leafing genotypes exhibited earlier tillering and more tiller numbers per plant, and its yield components including the number of panicles per plant and number of grains per panicle were superior to those of the slow leafing genotypes. Further research and application feasibility of the rapid leafing genotype in breeding were discussed.
基金supported by Jiangsu Natural Science Fund, China (Grant No.BK20131224)Agricultural Prospective Fund from Yangzhou, China (Grant No.YZ2014168)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Narrow genetic background is a key limiting factor in breeding stable high-yielding rice. The introduction and utilization of international rice core germplasm is an important way to increase the genetic diversity of domestic rice varieties. We conducted a genome-wide association study on 5 panicle traits of 315 rice accessions introduced from the international rice micro-core germplasm bank. Based on the tests from Yangzhou of China and Arkansas of American, environment exhibited a significant impacts on panicle length and primary branch number, while grain length, grain width and grain length/width ratio were insensitive to environment changes. We discovered a total of 7, 5, 10, 8 and 6 chromosomal regions or single nucleotide polymorphism marker loci that were significantly associated with primary branch number, panicle length, grain length, grain width and grain length/width ratio, respectively. Among them, eleven regions were associated with grain shape and one region associated with primary branch number, showing the good consistence in two different environments. Significant linear correlation was discovered between the average trait value and the number of favorable alleles carried by the varieties in all associated loci. Among the associated loci, varieties in aromatic and tropical japonica sub-groups possessed most favorable alleles, while those in temperate japonica sub-group contained the least. The domestic varieties mainly harbored unfavorable alleles in six of the associated loci being detected. On the contrary, 15 varieties from 11 different countries harbored more favorable alleles （as many as 30 or more） than the others. Remarkably, all these 15 varieties belonged to the tropical japonica sub-group. In conclusion, our study demonstrates that varieties in the tropical japonica sub-group had high potentials for breeding stable high-yielding rice. Based on this discovery, we proposed a new approach for improving the panicle traits of domestic rice by using tropical japonica varieties.
基金supported by the National Natural Science Foundation of China(Grant Nos.91750104,11704004,11704149,and 11474130)the Natural Science Foundation of Jilin Province,China(Grant No.20180101289JC)
文摘By using a heated molecular beam in combination with a time-of-flight mass spectrometer, we experimentally study the ionization of vibrational-hot carbon disulfide（CS2） molecules irradiated by a linearly polarized 800-nm 50-fs strong laser field. The ion yields are measured in a laser intensity range of 7.0 × 10^（12） W/cm^2–1.5 × 10^（14） W/cm^2 at different molecular temperatures of up to 1400 K. Enhanced ionization yield is observed for vibrationally excited CS2 molecules.The results show that the enhancement decreases as the laser intensity increases, and exhibits non-monotonical dependence on the molecular temperature. According to the calculated potential energy curves of the neutral and ionic electronic states of CS2, as well as the theoretical models of molecular strong-field ionization available in the literature, we discuss the mechanism of the enhanced ionization of vibrational-hot molecules. It is indicated that the enhanced ionization could be attributed to both the reduced ionization potential with vibrational excitation and the Frank–Condon factors between the neutral and ionic electronic states. Our study paves the way to understanding the effect of nuclear motion on the strongfield ionization of molecules, which would give a further insight into theoretical and experimental investigations on the interaction of polyatomic molecules with strong laser fields.
基金supported by grants from Jiangsu Province Self-innovation Program,China (CX(13)5073)the Natural Science Foundation of Jiangsu Province of China (BK20141291)the Jiangsu 333 Program,China (BRA2014170)
文摘Cuticular wax plays an important role in protecting plants against water loss and pathogen infection and in the adaptations to environmental stresses. The genetic mechanism of the biosynthesis and accumulation of epicuticular wax in rice remains largely unknown. Here, we show a spontaneous mutant displaying wax crystal-sparse leaves and decreased content of epicuticular wax that was derived from the cytoplasmic male sterility （CMS） restorer line Zhenhui 714. Compared with the wild type Zhenhui 714, the mutant exhibited hydrophilic features on leaf surface and more sensitivity to drought stress. The mutation also caused lower grain number per panicle and thousand grain weight, leading to the decline of yield. Genetic analysis indicates that the mutation is controlled by a single recessive gene, named wax crystal-sparse leaf3 （wsl3）. Using segregation populations derived from crosses of mutant/Zhendao 88 and mutant/Wuyujing 3, respectively, the wsl3 gene was fine-mapped to a 110-kb region between markers c3-16 and c3-22 on chromosome 3. According to the rice reference genome and gene analysis, we conclude that a novel gene/mechanism involved in regulation of rice cuticular wax formation.
文摘设计了一台以增强型氮化镓(eGaN)高电子迁移率晶体管(HEMT)为开关器件的450 W DC/DC模块电源。主功率电路采用同步整流Buck+软开关推挽的两级结构。针对eGaN HEMT应用中的驱动回路寄生电感的影响和驱动印制电路板(PCB)设计改善、开关管死区时间对软开关效果的影响和优化、eGaN HEMT主电路多层PCB布局等关键设计进行了介绍。最后,搭建八层板结构的样机,实测效率可达95%,证明了设计的合理性。
文摘目的了解湖北恩施地区和武汉地区手足口病(hand,foot and mouth disease,HFMD)病原体肠道病毒71型(EV-A71)VP1的基因特征。方法收集2010年来自于恩施地区和武汉地区的78例HFMD患儿的咽拭子标本。通过标本接种病毒易感Vero细胞,对产生明显细胞病变效应的阳性标本进行初筛。利用PCR法对初筛阳性标本进行进一步鉴定,对阳性毒株VP1基因序列进行扩增,将其构建到pMD18-T载体上,最后对VP1全长序列进行测序。通过构建系统进化树分析2010年湖北恩施地区和武汉地区EV-A71病毒株的基因型,并分析探讨其与2010年中国大陆其他地区EV-A71病毒株之间的进化关系。结果从78例手足口病标本中分离得到9株EV-A71,进一步对其VP1序列进行系统进化分析发现所有EV-A71分离株均属于C4亚型。2010年恩施地区和武汉地区EV-A71病毒株与2010年中国大陆其他地区EV-A71病毒株在同一进化分支。本研究中分离自伴随震颤患者的EV-A71病毒株(wh64-CHN-10)的VP1-240位点氨基酸残基为丙氨酸,而其余分离自轻症手足口病患者的8株EV-A71病毒株的VP1-240位点为苏氨酸。结论 EV-A71是2010-2011年恩施和武汉地区手足口病的重要病原体之一,属于C4基因型,VP1-240位点的氨基酸可能影响EV-A71的毒力。
