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
Effects of rolled leaf gene Rl（t） on grain quality characters of hybrid rice were analyzed by using three pairs of rolled leaf near-isogenic lines under two fertilizer treatments. Under normal fertilizer level （e.g...Effects of rolled leaf gene Rl（t） on grain quality characters of hybrid rice were analyzed by using three pairs of rolled leaf near-isogenic lines under two fertilizer treatments. Under normal fertilizer level （e.g. 450 kg urea per ha）, head rice rates and milled rice recovery of rolled leaf hybrids were significantly higher than those of corresponding non-rolled crosses, while the chalky rice rate and chalkiness were all lower. Of the RVA profiles, the peak viscosity, the hot paste viscosity and the breakdown viscosity of the rolled were all higher than those of the corresponding non-rolled ones to various degrees. Increasing fertilizer application for promoting panicle development increased the brown, milled and head rice rates except for Shanyou 63, furthermore, significant difference of head rice rates existed between the rolled leaf Shanyou 559 and Shanyou 559; while the peak viscosity, the hot paste viscosity and the breakdown viscosity all decreased to different levels; changes of values of other characters had no apparent regularity. It suggested that Rl（t） could improve rice quality under certain conditions.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
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
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
目的建立麻疹疫苗株Schwarz(MVSW)反向遗传系统。方法将MVSW全长cDNA分为F1~F7共7个片段,在F1片段的5′端插入T7启动子及锤头核酸酶序列(hammerhead ribozyme,HamRz),F7片段的3′端插入T7终止子及丁型肝炎病毒核酶序列(hepatitis D viru...目的建立麻疹疫苗株Schwarz(MVSW)反向遗传系统。方法将MVSW全长cDNA分为F1~F7共7个片段,在F1片段的5′端插入T7启动子及锤头核酸酶序列(hammerhead ribozyme,HamRz),F7片段的3′端插入T7终止子及丁型肝炎病毒核酶序列(hepatitis D virus ribozyme,HdvRz),分别将F1~F7片段克隆至pT7-MCS2载体上,7个重组质粒经酶切按顺序拼接MVSW全长cDNA,获得全长质粒pT7MVSW。同时构建表达MVSW核蛋白(N)、磷蛋白(P)、大蛋白(L)的3个辅助质粒。将全长质粒与3个辅助质粒及表达T7RNA聚合酶的质粒(pT7-T7RNAP及pCDIBP-T7RNAP)共同电转染Vero细胞,拯救获得病毒rMV_(SW)。收获的rMV_(SW)在Vero及CEC细胞中进行传代培养,观察细胞病变、检测病毒滴度并进行病毒测序,同时免疫小鼠检测抗r MVSW中和抗体。结果经酶切鉴定,全长质粒及辅助质粒均构建正确。拯救病毒rMV_(SW)在Vero及CEC细胞培养的病变典型特征类似;P2代病毒rMV_(SW)扩增片段与疫苗株MVSW理论序列一致;rMV_(SW)经Vero细胞连续培养P2~P10代病毒滴度稳定在5.5~6.5 lgCCID_(50)/mL之间;rMV_(SW)及疫苗株MVS191诱导的抗rMV_(SW)抗体滴度接近。结论成功建立了麻疹疫苗株MVSW的反向遗传系统,获得的具有良好遗传稳定性及免疫原性的拯救病毒rMV_(SW)有作为疫苗生产用毒种的潜力。展开更多
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.
文摘Effects of rolled leaf gene Rl（t） on grain quality characters of hybrid rice were analyzed by using three pairs of rolled leaf near-isogenic lines under two fertilizer treatments. Under normal fertilizer level （e.g. 450 kg urea per ha）, head rice rates and milled rice recovery of rolled leaf hybrids were significantly higher than those of corresponding non-rolled crosses, while the chalky rice rate and chalkiness were all lower. Of the RVA profiles, the peak viscosity, the hot paste viscosity and the breakdown viscosity of the rolled were all higher than those of the corresponding non-rolled ones to various degrees. Increasing fertilizer application for promoting panicle development increased the brown, milled and head rice rates except for Shanyou 63, furthermore, significant difference of head rice rates existed between the rolled leaf Shanyou 559 and Shanyou 559; while the peak viscosity, the hot paste viscosity and the breakdown viscosity all decreased to different levels; changes of values of other characters had no apparent regularity. It suggested that Rl（t） could improve rice quality under certain conditions.
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.
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 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.
