Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and s...Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.展开更多
Recently,security issues of smart contracts are arising great attention due to the enormous financial loss caused by vulnerability attacks.There is an increasing need to detect similar codes for hunting vulnerability ...Recently,security issues of smart contracts are arising great attention due to the enormous financial loss caused by vulnerability attacks.There is an increasing need to detect similar codes for hunting vulnerability with the increase of critical security issues in smart contracts.Binary similarity detection that quantitatively measures the given code diffing has been widely adopted to facilitate critical security analysis.However,due to the difference between common programs and smart contract,such as diversity of bytecode generation and highly code homogeneity,directly adopting existing graph matching and machine learning based techniques to smart contracts suffers from low accuracy,poor scalability and the limitation of binary similarity on function level.Therefore,this paper investigates graph neural network to detect smart contract binary code similarity at the program level,where we conduct instruction-level normalization to reduce the noise code for smart contract pre-processing and construct contract control flow graphs to represent smart contracts.In particular,two improved Graph Convolutional Network(GCN)and Message Passing Neural Network(MPNN)models are explored to encode the contract graphs into quantitatively vectors,which can capture the semantic information and the program-wide control flow information with temporal orders.Then we can efficiently accomplish the similarity detection by measuring the distance between two targeted contract embeddings.To evaluate the effectiveness and efficient of our proposed method,extensive experiments are performed on two real-world datasets,i.e.,smart contracts from Ethereum and Enterprise Operation System(EOS)blockchain-based platforms.The results show that our proposed approach outperforms three state-of-the-art methods by a large margin,achieving a great improvement up to 6.1%and 17.06%in accuracy.展开更多
Objective Injured tubular reabsorption is highlighted as one of the causes of increased albuminuria in the early stage of diabetic nephropathy;however,the underlying mechanism has not been fiilly elucidated.In this st...Objective Injured tubular reabsorption is highlighted as one of the causes of increased albuminuria in the early stage of diabetic nephropathy;however,the underlying mechanism has not been fiilly elucidated.In this study,we aimed to explore whether reducing inflammation and remodeling the insulin signaling pathway could improve albumin uptake of renal tubules.Methods 8-week-old male db/db mice(n=8),a type 2 diabetic nephropathy model,administered with nuclear factor kappa-B(NF-kB)inhibitor parthenolide(PTN,1 mg/kg)intraperitoneally every other day for 8 weeks,were as the treatment group.Meanwhile,the age-matched male db/m mice(n=S)and db/db mice(n=8)were treated with saline as the control group and type 2 diabetic nephropathy group.When the mice were sacrificed,blood and urine were collected to examine homeostasis model assessment of insulin resistance(HOMA-IR)and urine albumin creatinine ratio,and kidney samples were used to analyze histopathologic changes with periodic acid-Schiff(PAS)staining,NF-kB p65,phosphorylation of AKT(p-AKT),amnionless and cubilin expressions with immunohistochemistry as well as western blot,and the albumin uptake of renal tubules by using immunofluorescence.In addition,HKC cells were divided into the insulin group treated with insulin alone,the TNF-a group treated with insulin and tumor necrosis factor(TNF-a),and the TNF-a+PTN group exposed to PTN,insulin and TNF-a.The levels of albumin uptake and expression levels of NF-kB p65,p-IRS-l/IRS-1,p-AKT/AKT,amnionless and cubilin in HKC cells were measured.Results Compared with the db/db group,the db/db+PTN group demonstrated decreased levels of HOMA-IR(36.83±14.09 vs.31.07+28.05)and urine albumin creatinine ratio(190.3±7.3 vs.143.0±97.6 mg/mmol);however,the differences were not statistically significant(P>0.05).Periodic acid-Schiff staining showed PTN could alleviate the glomerular hypertrophy and reduce the matrix in mesangial areas of db/db mice.The renal expression of NF-kB p65 was increased and p-AKT(s473)decreased in the db/db group compared with the db/m group(P<0.05).PTN significantly reduced the renal expression of NF-kB p65 and ameliorated the decline of p-AKT(s473)compared with the db/db group(P<0.05).Compared with the db/m group,the expression of amnionless and cubilin decreased and albumin uptake in tubules were reduced in the db/db group(P<0.05),and PTN could significantly increase the expression of cubilin(P<0.05),and improve albumin uptake in tubules.Insulin promoted albumin uptake and the expression of amnionless and cubilin in HKC cells(P<0.05).TNF-a stimulated the expression of NF-kB p65,increased p-IRS-1(s307)and reduced p-AKT(s473)in HKC cells(PV 0.05).In theTNF-a+PTN group,the expression of NF-kB p65 declined and p-IRS-1(s307)and p-AKT(s473)were restored,compared with theTNF-a group(P<0.05).The expression of amnionless and cubilin decreased in theTNF-a group(P<0.05),and PTN could significantly increase the expression of cubilin(P<0.05).Conclusions Inflammation caused damage to insulin signaling,which reduced amnionless-cubilin expression and albumin uptake.PTN could reduce inflammation and remodel the impaired insulin signaling pathway,which promoted the expression of cubilin and albumin uptake.Our study can shed light on the role of inflammation in the reduction of albumin uptake of renal tubules in type 2 diabetic nephropathy.展开更多
Crop breeding aims to generate pure in bred lines with multiple desired traits. Doubled haploid (DH) and genome editing using CRISPR/Cas9 are two powerful game-changing technologies in crop breeding. However, both of ...Crop breeding aims to generate pure in bred lines with multiple desired traits. Doubled haploid (DH) and genome editing using CRISPR/Cas9 are two powerful game-changing technologies in crop breeding. However, both of them still fall short for rapid generation of pure elite lines with integrated favorable traits. Here, we report the development of a Haploid-Inducer Mediated Genome Editing (IMGE) approach, which utilizes a maize haploid inducer line carrying a CRISPR/Cas9 cassette targeting for a desired agronomic trait to pollinate an elite maize in bred line and to generate genome-edited haploids in the elite maize background. Homozygous pure DH lines with the desired trait improvement could be generated within two generations, thus bypassing the lengthy procedure of repeated crossing and backcrossing used in conventional breeding for integrating a desirable trait into elite commercial backgrounds.展开更多
Maize(Zea mays) root system architecture(RSA)mediates the key functions of plant anchorage and acquisition of nutrients and water. In this study,a set of 204 recombinant inbred lines(RILs) was derived from the widely ...Maize(Zea mays) root system architecture(RSA)mediates the key functions of plant anchorage and acquisition of nutrients and water. In this study,a set of 204 recombinant inbred lines(RILs) was derived from the widely adapted Chinese hybrid ZD958(Zheng58 Chang7-2),genotyped by sequencing(GBS) and evaluated as seedlings for 24 RSA related traits divided into primary,seminal and total root classes. Signi ficant differences between the means of the parental phenotypes were detected for 18 traits,and extensive transgressive segregation in the RIL population was observed for all traits. Moderate to strong relationships among the traits were discovered. A total of 62 quantitative trait loci(QTL) were identi fied that individually explained from1.6% to 11.6%(total root dry weight/total seedling shoot dry weight) of the phenotypic variation. Eighteen,24 and 20 QTL were identi fied for primary,seminal and total root classes of traits,respectively. We found hotspots of 5,3,4 and 12 QTL in maize chromosome bins 2.06,3.02-03,9.02-04,and 9.05-06,respectively,implicating the presence of root gene clusters or pleiotropic effects. These results characterized the phenotypic variation and genetic architecture of seedling RSA in a population derived from a successful maize hybrid.展开更多
In response to competition for light from their neighbors,shade-intolerant plants flower precociously to ensure reproductive success and survival.However,the molecular mechanisms underlying this key developmental swit...In response to competition for light from their neighbors,shade-intolerant plants flower precociously to ensure reproductive success and survival.However,the molecular mechanisms underlying this key developmental switch are not well understood.Here,we show that a pair of Arabidopsis transcription factors essential for phytochrome A signaling,FAR-RED ELONGATED HYPOCOTYL3(FHY3)and FAR-RED IMPAIRED RESPONSE1(FAR1),regulate flowering time by integrating environmental light signals with the miR156-SPL module-mediated aging pathway.We found that FHY3 and FAR1 directly interact with three flowering-promoting SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE(SPL)transcription factors,SPL3,SPL4,and SPL5,and inhibit their binding to the promoters of several key flowering regulatory genes,including FRUITFUL(FUL),LEAFY(LFY),APETALA1(AP1),and MIR172C,thus downregulating their transcript levels and delaying flowering.Under simulated shade conditions,levels of SPL3/4/5 proteins increase,whereas levels of FHY3 and FAR1 proteins decline,thus releasing SPL3/4/5 from FHY3/FAR1 inhibition to allow activation of FUL,LFY,AP1,and MIR172C and,consequently,early flowering.Taken together,these results unravel a novel mechanism whereby plants regulate flowering time by integrating environmental cues(such as light conditions)and an internal developmental program(the miR156-SPL module-mediated aging pathway).展开更多
Although the genetic basis for endosperm development in maize(Zea mays)has been well studied,the mechanism for coordinating grain filling with increasing kernel size remains elusive.Here,we report that increased kerne...Although the genetic basis for endosperm development in maize(Zea mays)has been well studied,the mechanism for coordinating grain filling with increasing kernel size remains elusive.Here,we report that increased kernel size was selected during modern breeding and identify a novel DELLA-like transcriptional regulator,ZmGRAS11,which positively regulates kernel size and kernel weight in maize.We find that Opaque2,a core transcription factor for zein protein and starch accumulation,transactivates the expression of Zm GRAS11.Our data suggest that the Opaque2-Zm GRAS11 module mediates synergistic endosperm enlargement with grain filling.展开更多
Maize(Zea mays ssp.mays)is a major staple crop,with the highest tonnage among cereal crops worldwide(FAO 2014).Over the past century,maize yields have increased about 8-fold in the US central Corm Belt(from 1,287 kg/h...Maize(Zea mays ssp.mays)is a major staple crop,with the highest tonnage among cereal crops worldwide(FAO 2014).Over the past century,maize yields have increased about 8-fold in the US central Corm Belt(from 1,287 kg/ha in the 19305 to 11,084 kg/ha in 2017,http://www.fao.org,Duvick 2005b)due to a combination of genetic gain resulting from breeding efforts and im-proved management practices(such as application of synthetic nitrogen fertilizers,weed,and pest control,increased efficiency of harvest equipment,etC.).A major management practice that contributed to the continuous yield increase is continual increases in planting density(from 30,000 plants per hectare or less in the 1930s to 80,000 plants per hectare or higher in the 1980s,Duvick 2005a,2005b).A series of retro-spective studies have suggested that newer hybrids yield more than older hybrids because of improved plant architecture better adapted to high density planting and increased ability to withstand various biotic and abiotic stresses associated with high density planting(ollenaar and Wu 1999;Duvick 2005a,2005b).Although lagging behind the United States,increasing planting density has been a popular practice in other countries as well for increasing grain yield per unit land area in the last few decades(Li et al.2011).展开更多
As essential B vitamin for humans, folates accumulation in edible parts of crops, such as maize kernels, Is of great importance for human health. But its breeding is always limited by the prohibitive cost of folate pr...As essential B vitamin for humans, folates accumulation in edible parts of crops, such as maize kernels, Is of great importance for human health. But its breeding is always limited by the prohibitive cost of folate profiling. The molecular breeding is a more executable and efficient way for folate fortification, but is limited by the molecular knowledge of folate regulation. Here we report the genetic mapping of folate quantitative trait loci (QTLs) using a segregated population crossed by two maize lines, one high in folate (GEMS31) and the other low in folate (DAN3130). Two folate QTLs on chromosome 5 were obtained by the combination of F2 whole-exome sequencing and F3 kernel-folate profiling. These two QTLs had been confirmed by bulk segregant analysis using F6 pooled DNA and F7 kernel-folate profiling, and were overlapped with QTLs identified by another segregated population. These two QTLs contributed 41.6% of phenotypic variation of 5-formyltetrahydrofolate, the most abundant storage form among folate derivatives in dry maize grains, in the GEMS31×DAN3130 population. Their fine mapping and functional analysis will reveal details of folate metabolism, and provide a basis for marker-assisted breeding aimed at the enrichment of folates in maize kernels.展开更多
基金supported by the Doctor Foundation of Gansu Academy of Agricultural Sciences,China(2020GAAS33)the Young Science and Technology Lifting Engineering Talents in Gansu Province,China(2020-18)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2017-ICS)。
文摘Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight.
基金supported by the Basic Research Program(No.JCKY2019210B029)Network threat depth analysis software(KY10800210013).
文摘Recently,security issues of smart contracts are arising great attention due to the enormous financial loss caused by vulnerability attacks.There is an increasing need to detect similar codes for hunting vulnerability with the increase of critical security issues in smart contracts.Binary similarity detection that quantitatively measures the given code diffing has been widely adopted to facilitate critical security analysis.However,due to the difference between common programs and smart contract,such as diversity of bytecode generation and highly code homogeneity,directly adopting existing graph matching and machine learning based techniques to smart contracts suffers from low accuracy,poor scalability and the limitation of binary similarity on function level.Therefore,this paper investigates graph neural network to detect smart contract binary code similarity at the program level,where we conduct instruction-level normalization to reduce the noise code for smart contract pre-processing and construct contract control flow graphs to represent smart contracts.In particular,two improved Graph Convolutional Network(GCN)and Message Passing Neural Network(MPNN)models are explored to encode the contract graphs into quantitatively vectors,which can capture the semantic information and the program-wide control flow information with temporal orders.Then we can efficiently accomplish the similarity detection by measuring the distance between two targeted contract embeddings.To evaluate the effectiveness and efficient of our proposed method,extensive experiments are performed on two real-world datasets,i.e.,smart contracts from Ethereum and Enterprise Operation System(EOS)blockchain-based platforms.The results show that our proposed approach outperforms three state-of-the-art methods by a large margin,achieving a great improvement up to 6.1%and 17.06%in accuracy.
基金the Natural Science Foundation of Beijing,China(Grant No.7122143).
文摘Objective Injured tubular reabsorption is highlighted as one of the causes of increased albuminuria in the early stage of diabetic nephropathy;however,the underlying mechanism has not been fiilly elucidated.In this study,we aimed to explore whether reducing inflammation and remodeling the insulin signaling pathway could improve albumin uptake of renal tubules.Methods 8-week-old male db/db mice(n=8),a type 2 diabetic nephropathy model,administered with nuclear factor kappa-B(NF-kB)inhibitor parthenolide(PTN,1 mg/kg)intraperitoneally every other day for 8 weeks,were as the treatment group.Meanwhile,the age-matched male db/m mice(n=S)and db/db mice(n=8)were treated with saline as the control group and type 2 diabetic nephropathy group.When the mice were sacrificed,blood and urine were collected to examine homeostasis model assessment of insulin resistance(HOMA-IR)and urine albumin creatinine ratio,and kidney samples were used to analyze histopathologic changes with periodic acid-Schiff(PAS)staining,NF-kB p65,phosphorylation of AKT(p-AKT),amnionless and cubilin expressions with immunohistochemistry as well as western blot,and the albumin uptake of renal tubules by using immunofluorescence.In addition,HKC cells were divided into the insulin group treated with insulin alone,the TNF-a group treated with insulin and tumor necrosis factor(TNF-a),and the TNF-a+PTN group exposed to PTN,insulin and TNF-a.The levels of albumin uptake and expression levels of NF-kB p65,p-IRS-l/IRS-1,p-AKT/AKT,amnionless and cubilin in HKC cells were measured.Results Compared with the db/db group,the db/db+PTN group demonstrated decreased levels of HOMA-IR(36.83±14.09 vs.31.07+28.05)and urine albumin creatinine ratio(190.3±7.3 vs.143.0±97.6 mg/mmol);however,the differences were not statistically significant(P>0.05).Periodic acid-Schiff staining showed PTN could alleviate the glomerular hypertrophy and reduce the matrix in mesangial areas of db/db mice.The renal expression of NF-kB p65 was increased and p-AKT(s473)decreased in the db/db group compared with the db/m group(P<0.05).PTN significantly reduced the renal expression of NF-kB p65 and ameliorated the decline of p-AKT(s473)compared with the db/db group(P<0.05).Compared with the db/m group,the expression of amnionless and cubilin decreased and albumin uptake in tubules were reduced in the db/db group(P<0.05),and PTN could significantly increase the expression of cubilin(P<0.05),and improve albumin uptake in tubules.Insulin promoted albumin uptake and the expression of amnionless and cubilin in HKC cells(P<0.05).TNF-a stimulated the expression of NF-kB p65,increased p-IRS-1(s307)and reduced p-AKT(s473)in HKC cells(PV 0.05).In theTNF-a+PTN group,the expression of NF-kB p65 declined and p-IRS-1(s307)and p-AKT(s473)were restored,compared with theTNF-a group(P<0.05).The expression of amnionless and cubilin decreased in theTNF-a group(P<0.05),and PTN could significantly increase the expression of cubilin(P<0.05).Conclusions Inflammation caused damage to insulin signaling,which reduced amnionless-cubilin expression and albumin uptake.PTN could reduce inflammation and remodel the impaired insulin signaling pathway,which promoted the expression of cubilin and albumin uptake.Our study can shed light on the role of inflammation in the reduction of albumin uptake of renal tubules in type 2 diabetic nephropathy.
基金National Key R&D Program of China (2016YFD0100303 and 2016YFD0101001)Beijing Natural Science Foundation (6172032).
文摘Crop breeding aims to generate pure in bred lines with multiple desired traits. Doubled haploid (DH) and genome editing using CRISPR/Cas9 are two powerful game-changing technologies in crop breeding. However, both of them still fall short for rapid generation of pure elite lines with integrated favorable traits. Here, we report the development of a Haploid-Inducer Mediated Genome Editing (IMGE) approach, which utilizes a maize haploid inducer line carrying a CRISPR/Cas9 cassette targeting for a desired agronomic trait to pollinate an elite maize in bred line and to generate genome-edited haploids in the elite maize background. Homozygous pure DH lines with the desired trait improvement could be generated within two generations, thus bypassing the lengthy procedure of repeated crossing and backcrossing used in conventional breeding for integrating a desirable trait into elite commercial backgrounds.
基金supported by 863 Project (2012AA10A305)Chinese Universities Scientific Fund (2014XJ036)+1 种基金NSF (31301321)948 Project (2011-G15)
文摘Maize(Zea mays) root system architecture(RSA)mediates the key functions of plant anchorage and acquisition of nutrients and water. In this study,a set of 204 recombinant inbred lines(RILs) was derived from the widely adapted Chinese hybrid ZD958(Zheng58 Chang7-2),genotyped by sequencing(GBS) and evaluated as seedlings for 24 RSA related traits divided into primary,seminal and total root classes. Signi ficant differences between the means of the parental phenotypes were detected for 18 traits,and extensive transgressive segregation in the RIL population was observed for all traits. Moderate to strong relationships among the traits were discovered. A total of 62 quantitative trait loci(QTL) were identi fied that individually explained from1.6% to 11.6%(total root dry weight/total seedling shoot dry weight) of the phenotypic variation. Eighteen,24 and 20 QTL were identi fied for primary,seminal and total root classes of traits,respectively. We found hotspots of 5,3,4 and 12 QTL in maize chromosome bins 2.06,3.02-03,9.02-04,and 9.05-06,respectively,implicating the presence of root gene clusters or pleiotropic effects. These results characterized the phenotypic variation and genetic architecture of seedling RSA in a population derived from a successful maize hybrid.
基金supported by grants from National Natural Science Foundation of China(31770210 and 31570191)National Key Research and D evelopm ent Program of China(2016YFD0100303).
文摘In response to competition for light from their neighbors,shade-intolerant plants flower precociously to ensure reproductive success and survival.However,the molecular mechanisms underlying this key developmental switch are not well understood.Here,we show that a pair of Arabidopsis transcription factors essential for phytochrome A signaling,FAR-RED ELONGATED HYPOCOTYL3(FHY3)and FAR-RED IMPAIRED RESPONSE1(FAR1),regulate flowering time by integrating environmental light signals with the miR156-SPL module-mediated aging pathway.We found that FHY3 and FAR1 directly interact with three flowering-promoting SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE(SPL)transcription factors,SPL3,SPL4,and SPL5,and inhibit their binding to the promoters of several key flowering regulatory genes,including FRUITFUL(FUL),LEAFY(LFY),APETALA1(AP1),and MIR172C,thus downregulating their transcript levels and delaying flowering.Under simulated shade conditions,levels of SPL3/4/5 proteins increase,whereas levels of FHY3 and FAR1 proteins decline,thus releasing SPL3/4/5 from FHY3/FAR1 inhibition to allow activation of FUL,LFY,AP1,and MIR172C and,consequently,early flowering.Taken together,these results unravel a novel mechanism whereby plants regulate flowering time by integrating environmental cues(such as light conditions)and an internal developmental program(the miR156-SPL module-mediated aging pathway).
基金supported by the National Natural Science Foundation of China to X.J.Z.(grant number 31771707)National Special Program for GMO Development of China to R.M.C.(2016ZX08003-002)the National Key Basic Research Program of China(2014CB138205)。
文摘Although the genetic basis for endosperm development in maize(Zea mays)has been well studied,the mechanism for coordinating grain filling with increasing kernel size remains elusive.Here,we report that increased kernel size was selected during modern breeding and identify a novel DELLA-like transcriptional regulator,ZmGRAS11,which positively regulates kernel size and kernel weight in maize.We find that Opaque2,a core transcription factor for zein protein and starch accumulation,transactivates the expression of Zm GRAS11.Our data suggest that the Opaque2-Zm GRAS11 module mediates synergistic endosperm enlargement with grain filling.
文摘Maize(Zea mays ssp.mays)is a major staple crop,with the highest tonnage among cereal crops worldwide(FAO 2014).Over the past century,maize yields have increased about 8-fold in the US central Corm Belt(from 1,287 kg/ha in the 19305 to 11,084 kg/ha in 2017,http://www.fao.org,Duvick 2005b)due to a combination of genetic gain resulting from breeding efforts and im-proved management practices(such as application of synthetic nitrogen fertilizers,weed,and pest control,increased efficiency of harvest equipment,etC.).A major management practice that contributed to the continuous yield increase is continual increases in planting density(from 30,000 plants per hectare or less in the 1930s to 80,000 plants per hectare or higher in the 1980s,Duvick 2005a,2005b).A series of retro-spective studies have suggested that newer hybrids yield more than older hybrids because of improved plant architecture better adapted to high density planting and increased ability to withstand various biotic and abiotic stresses associated with high density planting(ollenaar and Wu 1999;Duvick 2005a,2005b).Although lagging behind the United States,increasing planting density has been a popular practice in other countries as well for increasing grain yield per unit land area in the last few decades(Li et al.2011).
基金financially supported by the Ministry of Science and Technology of China (2016YFD0100503 to L.J.)the National Natural Science Foundation of China (31870283 to L.J.)+1 种基金Shanghai Agriculture Applied Technology Development Program (Z20180103 to L.J.)Beijing Natural Science Foundation (6172032 to B.W.)
文摘As essential B vitamin for humans, folates accumulation in edible parts of crops, such as maize kernels, Is of great importance for human health. But its breeding is always limited by the prohibitive cost of folate profiling. The molecular breeding is a more executable and efficient way for folate fortification, but is limited by the molecular knowledge of folate regulation. Here we report the genetic mapping of folate quantitative trait loci (QTLs) using a segregated population crossed by two maize lines, one high in folate (GEMS31) and the other low in folate (DAN3130). Two folate QTLs on chromosome 5 were obtained by the combination of F2 whole-exome sequencing and F3 kernel-folate profiling. These two QTLs had been confirmed by bulk segregant analysis using F6 pooled DNA and F7 kernel-folate profiling, and were overlapped with QTLs identified by another segregated population. These two QTLs contributed 41.6% of phenotypic variation of 5-formyltetrahydrofolate, the most abundant storage form among folate derivatives in dry maize grains, in the GEMS31×DAN3130 population. Their fine mapping and functional analysis will reveal details of folate metabolism, and provide a basis for marker-assisted breeding aimed at the enrichment of folates in maize kernels.
