Chlorophyll(Chl) biosynthesis is essential for photosynthesis and plant growth.Glutamyl-tRNA reductase(GluTR) catalyzes glutamyl-tRNA into glutamate-1-semialdehyde(GSA) and initiates the chlorophyll biosynthesis.Even ...Chlorophyll(Chl) biosynthesis is essential for photosynthesis and plant growth.Glutamyl-tRNA reductase(GluTR) catalyzes glutamyl-tRNA into glutamate-1-semialdehyde(GSA) and initiates the chlorophyll biosynthesis.Even though the main role of GluTR has been established,the effects caused by natural variations in its corresponding gene remain largely unknown.Here,we characterized a spontaneous mutant in paddy field with Chl biosynthesis deficiency,designated as cbd1.With intact thylakoid lamellar structure,the cbd1 plant showed light green leaves and reduced Chl and carotenoids(Cars) content significantly compared to the wild type.By map-based gene cloning,the mutation was restricted within a 57-kb region on chromosome 10,in which an mPingA miniature inverted-repeat transposable element(MITE) inserted in the promoter region of OsHemA gene.Both leaf color and the pigment contents in cbd1 were recovered in a complementation test,confirming OsHemA was responsible for the mutant phenotype.OsHemA was uniquely predicted to encode GluTR and its expression level was dramatically repressed in cbd1.Transient transformation in protoplasts demonstrated that GluTR localized in chloroplasts and a signal peptide exists in its N-terminus.A majority of Chl biosynthesis genes,except for POR and CHLG,were down-regulated synchronously by the repression of OsHemA,suggesting that an attenuation occurred in the Chl biosynthesis pathway.Interestingly,we found major agronomic traits involved in rice yield were statistically unaffected,except for the number of full grains per panicle was increased in cbd1.Collectively,OsHemA plays an essential role in Chl biosynthesis in rice and its weak allele can adjust leaf color and Chls content without compromise to rice yield.展开更多
Tricheary elements （TEs）, wrapped by secondary cell wall, play essential roles in water, mineral, and nutrient transduction. Cadmium （Cd） is a toxic heavy metal that is absorbed by roots and transported to shoot, ...Tricheary elements （TEs）, wrapped by secondary cell wall, play essential roles in water, mineral, and nutrient transduction. Cadmium （Cd） is a toxic heavy metal that is absorbed by roots and transported to shoot, leaves, and grains through vascular systems in plants. As rice is a major source of Cd intake, many efforts have been made to establish ＇low- Cd rice＇. However, no links have been found between cellulose biosynthesis and cadmium accumulation. We report here a rice brittle culm13 mutant, resulting from a novel missense mutation （G101K） in the N-terminus of cellulose synthase subunit 9 （CESA9）. Except for the abnormal mechanical strength, the mutant plants are morphologically indistinguishable from the wild-type plants. Transmission electron microscopy （TEM） and chemical analyses showed a slight reduction in secondary wall thickness and 22% decrease in cellulose content in bc13 plants. Moreover, this mutation unexpectedly confers the mutant plants Cd tolerance due to less Cd accumulation in leaves. Expression analysis of the genes required for Cd uptake and transport revealed complicated alterations after applying Cd to wild-type and bc13. The mutants were further found to have altered vascular structure. More importantly, Cd concentration in the xylem saps from the bc13 plants was significantly lower than that from the wild-type. Combining the analyses of CESA9 gene expression and Cd content retention in the cell-wall residues, we conclude that CESA9^G101K mutation alters cell-wall properties in the conducting tissues, which consequently affects Cd translocation efficiency that largely contributes to the low Cd accumulation in the mutant plants.展开更多
AIM: To evaluate the effects of etanercept on the expression of Fas, tumor necrosis factor-alpha(TNF-α) and caspase-8 in the early stage of the apoptotic pathway in diabetic rats, and to explore the therapeutic effec...AIM: To evaluate the effects of etanercept on the expression of Fas, tumor necrosis factor-alpha(TNF-α) and caspase-8 in the early stage of the apoptotic pathway in diabetic rats, and to explore the therapeutic effect of etanercept on diabetic retinopathy.METHODS: A total of 60 Sprague-Dawley(SD) rats were randomly and evenly divided into 3 groups with 20 rats each, including control group, and diabetic groups with or without treatment. Streptozotocin(STZ)-induced diabetic rats were established for diabetic groups. Blood glucose and body weight were measured weekly. All the rats were sacrificed at the 12 wk after treatment. The expressions of Fas, TNF-α and caspase-8 in rat retina were quantitatively detected by PCR and Western blot. The leakage of Evan blue was adopted to measure the retinal vascular leakage quantitatively, and to compare it among different groups. TUNEL method was used to compare the amount of apoptotic bodies quantitatively in rat retina ganglion cells under electron microscope.RESULTS: The expressions of Fas, TNF-α and caspase-8 in each group were compared via PCR and Western blot, in which the diabetic group with treatment was lower than those without treatment(P<0.01), but all the diabetic groups were higher than the control group(P<0.01). Evans blue leakage in the diabetic treatment group was lower than those without treatment(P<0.01), but those in the control group was the lowest compared with the other two groups(P<0.01). TUNEL method showed that the apoptoticbodies of retina in the diabetic treatment group was lower than those without treatment(P<0.01), while those in the control group was the lowest compared with the other two groups(P<0.01). CONCLUSION: Etanercept can effectively reduce the expression of Fas, TNF-α and caspase-8, as well as the retinal leakage and retinal cell apoptosis in diabetic rats.展开更多
AIM:To identify genetic defects in a Chinese family with congenital posterior polar cataracts and assess the pathogenicity.METHODS:A four-generation Chinese family affected with autosomal dominant congenital cataract ...AIM:To identify genetic defects in a Chinese family with congenital posterior polar cataracts and assess the pathogenicity.METHODS:A four-generation Chinese family affected with autosomal dominant congenital cataract was recruited.Nineteen individuals took part in this study including 5 affected and 14 unaffected individuals.Sanger sequencing targeted hot-spot regions of 27 congenital cataract-causing genes for variant discovery.The pathogenicity of the variant was evaluated by the guidelines of American College of Medical Genetics and InterVar software.Confocal microscopy was applied to detect the subcellular localization of fluorescence-labeled ephrin type-A receptor 2(EPHA2).Co-immunoprecipitation assay was implemented to estimate the interaction between EphA2 and other lens membrane proteins.The mRNA and protein expression were analyzed by reverse transcription-polymerase chain reaction(qRT-PCR)and Western blotting assay,respectively.The cell migration was analyzed by wound healing assay.Zebrafish model was generated by ectopic expression of human EPHA2/p.R957P mutant to demonstrate whether the mutant could cause lens opacity in vivo.RESULTS:A novel missense and pathogenic variant c.2870G>C was identified in the sterile alpha motif(SAM)domain of EPHA2.Functional studies demonstrated the variant’s impact:reduced EPHA2 protein expression,altered subcellular localization,and disrupted interactions with other lens membrane proteins.This mutant notably enhanced human lens epithelial cell migration,and induced a central cloudy region and roughness in zebrafish lenses with ectopic expression of human EPHA2/p.R957P mutant under differential interference contrast(DIC)optics.CONCLUSION:Novel pathogenic c.2870G>C variant of EPHA2 in a Chinese congenital cataract family contributes to disease pathogenesis.展开更多
基金supported by the National Key Research and Development Program of China(2016YFD0101801)the National Excellent Doctoral Dissertation of China(201262)+2 种基金the Key Laboratory of Biology,Genetics and Breeding of Japonica Rice in Mid-lower Yangtze River,Ministry of Agriculture and Rural Affairs,China,the Collaborative Innovation Center for Hybrid Rice in Yangtze River,China,and the Jiangsu Collaborative Innovation Center for Modern Crop Production,China,the National High-Tech R&D Program of China(2014AA10A603-15)the National Key Technologies R&D Program of China during the 12th Five-Year Plan period(2013BAD01B02-16)the Jiangsu Science and Technology Development Program,China(BE2014394 and BE2015363)
文摘Chlorophyll(Chl) biosynthesis is essential for photosynthesis and plant growth.Glutamyl-tRNA reductase(GluTR) catalyzes glutamyl-tRNA into glutamate-1-semialdehyde(GSA) and initiates the chlorophyll biosynthesis.Even though the main role of GluTR has been established,the effects caused by natural variations in its corresponding gene remain largely unknown.Here,we characterized a spontaneous mutant in paddy field with Chl biosynthesis deficiency,designated as cbd1.With intact thylakoid lamellar structure,the cbd1 plant showed light green leaves and reduced Chl and carotenoids(Cars) content significantly compared to the wild type.By map-based gene cloning,the mutation was restricted within a 57-kb region on chromosome 10,in which an mPingA miniature inverted-repeat transposable element(MITE) inserted in the promoter region of OsHemA gene.Both leaf color and the pigment contents in cbd1 were recovered in a complementation test,confirming OsHemA was responsible for the mutant phenotype.OsHemA was uniquely predicted to encode GluTR and its expression level was dramatically repressed in cbd1.Transient transformation in protoplasts demonstrated that GluTR localized in chloroplasts and a signal peptide exists in its N-terminus.A majority of Chl biosynthesis genes,except for POR and CHLG,were down-regulated synchronously by the repression of OsHemA,suggesting that an attenuation occurred in the Chl biosynthesis pathway.Interestingly,we found major agronomic traits involved in rice yield were statistically unaffected,except for the number of full grains per panicle was increased in cbd1.Collectively,OsHemA plays an essential role in Chl biosynthesis in rice and its weak allele can adjust leaf color and Chls content without compromise to rice yield.
基金This work was supported by grants from the Ministry of Agriculture of China for transgenic research （2011ZX08009- 003） the Ministry of Sciences and Technology of China （2012CB114501） and the National Natural Science Foundation of China （31125019）.We thank Tai-Hua Zhang （Institute of Mechanics, Chinese Academy of Sciences, Beijing, China） for measurement of breaking force of rice plants, and Hong-Zhi Zhang （Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China） for elemental analysis. No conflict of interest declared.
文摘Tricheary elements （TEs）, wrapped by secondary cell wall, play essential roles in water, mineral, and nutrient transduction. Cadmium （Cd） is a toxic heavy metal that is absorbed by roots and transported to shoot, leaves, and grains through vascular systems in plants. As rice is a major source of Cd intake, many efforts have been made to establish ＇low- Cd rice＇. However, no links have been found between cellulose biosynthesis and cadmium accumulation. We report here a rice brittle culm13 mutant, resulting from a novel missense mutation （G101K） in the N-terminus of cellulose synthase subunit 9 （CESA9）. Except for the abnormal mechanical strength, the mutant plants are morphologically indistinguishable from the wild-type plants. Transmission electron microscopy （TEM） and chemical analyses showed a slight reduction in secondary wall thickness and 22% decrease in cellulose content in bc13 plants. Moreover, this mutation unexpectedly confers the mutant plants Cd tolerance due to less Cd accumulation in leaves. Expression analysis of the genes required for Cd uptake and transport revealed complicated alterations after applying Cd to wild-type and bc13. The mutants were further found to have altered vascular structure. More importantly, Cd concentration in the xylem saps from the bc13 plants was significantly lower than that from the wild-type. Combining the analyses of CESA9 gene expression and Cd content retention in the cell-wall residues, we conclude that CESA9^G101K mutation alters cell-wall properties in the conducting tissues, which consequently affects Cd translocation efficiency that largely contributes to the low Cd accumulation in the mutant plants.
基金Supported by National Natural Science Foundation of China(No.81270999)the Key Project of Miaopu of Fujian Medical University(No.2015MP004)the Qihang Funds of Fujian Medical University(No.2018QH1063)
文摘AIM: To evaluate the effects of etanercept on the expression of Fas, tumor necrosis factor-alpha(TNF-α) and caspase-8 in the early stage of the apoptotic pathway in diabetic rats, and to explore the therapeutic effect of etanercept on diabetic retinopathy.METHODS: A total of 60 Sprague-Dawley(SD) rats were randomly and evenly divided into 3 groups with 20 rats each, including control group, and diabetic groups with or without treatment. Streptozotocin(STZ)-induced diabetic rats were established for diabetic groups. Blood glucose and body weight were measured weekly. All the rats were sacrificed at the 12 wk after treatment. The expressions of Fas, TNF-α and caspase-8 in rat retina were quantitatively detected by PCR and Western blot. The leakage of Evan blue was adopted to measure the retinal vascular leakage quantitatively, and to compare it among different groups. TUNEL method was used to compare the amount of apoptotic bodies quantitatively in rat retina ganglion cells under electron microscope.RESULTS: The expressions of Fas, TNF-α and caspase-8 in each group were compared via PCR and Western blot, in which the diabetic group with treatment was lower than those without treatment(P<0.01), but all the diabetic groups were higher than the control group(P<0.01). Evans blue leakage in the diabetic treatment group was lower than those without treatment(P<0.01), but those in the control group was the lowest compared with the other two groups(P<0.01). TUNEL method showed that the apoptoticbodies of retina in the diabetic treatment group was lower than those without treatment(P<0.01), while those in the control group was the lowest compared with the other two groups(P<0.01). CONCLUSION: Etanercept can effectively reduce the expression of Fas, TNF-α and caspase-8, as well as the retinal leakage and retinal cell apoptosis in diabetic rats.
基金Supported by the Natural Science Foundation of Fujian Province(No.2021J01229)National Key Research and Development Program of China(No.2016YFC1000307).
文摘AIM:To identify genetic defects in a Chinese family with congenital posterior polar cataracts and assess the pathogenicity.METHODS:A four-generation Chinese family affected with autosomal dominant congenital cataract was recruited.Nineteen individuals took part in this study including 5 affected and 14 unaffected individuals.Sanger sequencing targeted hot-spot regions of 27 congenital cataract-causing genes for variant discovery.The pathogenicity of the variant was evaluated by the guidelines of American College of Medical Genetics and InterVar software.Confocal microscopy was applied to detect the subcellular localization of fluorescence-labeled ephrin type-A receptor 2(EPHA2).Co-immunoprecipitation assay was implemented to estimate the interaction between EphA2 and other lens membrane proteins.The mRNA and protein expression were analyzed by reverse transcription-polymerase chain reaction(qRT-PCR)and Western blotting assay,respectively.The cell migration was analyzed by wound healing assay.Zebrafish model was generated by ectopic expression of human EPHA2/p.R957P mutant to demonstrate whether the mutant could cause lens opacity in vivo.RESULTS:A novel missense and pathogenic variant c.2870G>C was identified in the sterile alpha motif(SAM)domain of EPHA2.Functional studies demonstrated the variant’s impact:reduced EPHA2 protein expression,altered subcellular localization,and disrupted interactions with other lens membrane proteins.This mutant notably enhanced human lens epithelial cell migration,and induced a central cloudy region and roughness in zebrafish lenses with ectopic expression of human EPHA2/p.R957P mutant under differential interference contrast(DIC)optics.CONCLUSION:Novel pathogenic c.2870G>C variant of EPHA2 in a Chinese congenital cataract family contributes to disease pathogenesis.
基金2018 Xiamen Medical and Health Project(Guiding Project)(No. 3502Z20189046)2020 Xiamen Medical and Health Project (Guiding Project)(No.3502Z20209224)。
