Rice yield and heading date are two distinct traits controlled by quantitative trait loci （QTLs）. The dissection of molecular mechanisms underlying rice yield traits is important for developing high-yielding rice va...Rice yield and heading date are two distinct traits controlled by quantitative trait loci （QTLs）. The dissection of molecular mechanisms underlying rice yield traits is important for developing high-yielding rice varieties. Here, we report the cloning and characterization of Ghd8, a major QTL with pleiotropic effects on grain yield, heading date, and plant height. Two sets of near isogenic line populations were developed for the cloning of GhdS. Ghd8 was narrowed down to a 20-kb region containing two putative genes, of which one encodes the OsHAP3 subunit of a CCAAT-box binding protein （HAP complex）; this gene was regarded as the Ghd8 candidate. A complementary test confirmed the identity and pleiotropic effects of the gene; interestingly, the genetic effect of Ghd8 was dependent on its genetic background. By regulating Ehdl, RFT1, and Hd3a, Ghd8 delayed flowering under long-day conditions, but promoted flowering under short-day conditions. Ghd8 up-regulated MOC1, a key gene controlling tillering and branching; this increased the number of tillers, primary and secondary branches, thus producing 50% more grains per plant. The ectopic expression of Ghd8 in Arabidopsis caused early flowering by 10 d-a situation similar to the one observed by its homolog AtHAP3b, when compared to wild-type under long-day conditions; these findings indicate the conserved function of Ghd8 and AtHAP3b in flowering in Arabidopsis. Our results demonstrated the important roles of Ghd8 in rice yield formation and flowering, as well as its opposite functions in flowering between rice and Arabidopsis under long-day conditions.展开更多
The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established hu...The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established human colon cancer cell lines: Colo-320 and SW1116. Treatments with 5-aza-2'-deoxycytidine (5-aza-dC) and trichostatin A, alone or in combination, were applied respectively. The methylation status of the CDKN2A promoter was determined by methyla-tion-specific PCR, and the acetylated status of the histones associated with the p21WAF1 and CDKN2A genes was examined by chromatin immunoprecipitation. The expression of the CDKN2A, p21WAF1, p53, p73, APC, c-myc, c-Ki-ras and survivin genes was detected by real-time RT-PCR and RT-PCR. The cell cycle profile was established by flow cytometry. We found that along with the demethylation of the CDKN2A gene promoter in both cell lines induced by 5-aza-dC alone or in combination with TSA, the expression of both CDKN2A and APC genes increased. The treatment of TSA or sodium butyrate up-regulated the transcription of p21WAF1 significantly by inducing the acetylation of histones H4 and H3, but failed to alter the acetylation level of CDKN2A-associated histones. No changes in transcription of p53, p73, c-myc, c-Ki-ras and survivin genes were observed. In addition, TSA or sodium butyrate was shown to arrest cells at the G1 phase. However, 5-aza-dC was not able to affect the cell cycle progression. In conclusion, regulation by epigenetic modification of the transcription of tumor-associated genes and the cell cycle progression in both human colon cancer cell lines Colo-320 and SW1116 is gene-specific.展开更多
Thinopyrum elongatum （2n = 2x = 14, EE）, a wild relative of wheat, has been suggested as a potentially novel source of resistance to several major wheat diseases including Fusarium Head Blight （FHB）. In this study...Thinopyrum elongatum （2n = 2x = 14, EE）, a wild relative of wheat, has been suggested as a potentially novel source of resistance to several major wheat diseases including Fusarium Head Blight （FHB）. In this study, a series of wheat （cv. Chinese Spring, CS） substitution and ditelosomic lines, including Th. elongatum additions, were assessed for Type II resistance to FHB. Results indicated that the lines containing chromosome 7E of Th. elongatum gave a high level of resistance to FHB, wherein the infection did not spread beyond the inoculated floret. Furthermore, it was determined that the novel resistance gene（s） of 7E was located on the short-ann （7ES） based on sharp difference in FHB resistance between the two 7E ditelosomic lines for each arm. On the other hand, Th. elongatum chromosomes 5E and 6E likely contain gene（s） for susceptibility to FHB because the disease spreads rapidly within the inoculated spikes of these lines. Genomic in situ hybridization （GISH） analysis revealed that the alien chromosomes in the addition and substitution lines were intact, and the lines did not contain discernible genomic aberrations. GISH and multicolor-GISH analyses were further performed on three trans- location lines that also showed high levels of resistance to FHB. Lines TA3499 and TA3695 were shown to contain one pair of wheat-Th. elongatum translocated chromosomes involving fragments of 7D plus a segment of the 7E, while line TA3493 was found to contain one pair of wheat-Th, elongatum translocated chromosomes involving the D- and A-genome chromosomes of wheat. Thus, this study has established that the short-arm of chromosome 7E of Th. elongatum harbors gene（s） highly resistant to the spreading of FHB, and chromatin of 7E introgressed into wheat chromosomes largely retained the resistance, implicating the feasibility of using these lines as novel material for breeding FHB-resistant wheat cultivars.展开更多
Introgression lines population was effectively used in mapping quantitative trait loci （QTLs）, identifying favorable genes, discovering hidden genetic variation, evaluating the action or interaction of QTLs in multi...Introgression lines population was effectively used in mapping quantitative trait loci （QTLs）, identifying favorable genes, discovering hidden genetic variation, evaluating the action or interaction of QTLs in multiple conditions and providing the favorable experimental materials for plant breeding and genetic research. In this study, an advanced backcross and consecutive selfing strategy was used to develop introgression lines （ILs）, which derived from an accession of Oryza rufipogon Griff. collected from Yuanjiang County, Yunnan Province of China, as the donor, and an elite indica cultivar Teqing （O. sativa L.）, as the recipient. Introgression segments from O. rufipogon were screened using 179 polymorphic simple sequence repeats （SSR） markers in the genome of each IL. Introgressed segments carried by the introgression lines population contained 120 ILs covering the whole O. rufipogon genome. The mean number of homozygous O. rufipogon segments per introgression line was about 3.88. The average length of introgressed segments was approximate 25.5 cM, and about 20.8% of these segments had sizes less than 10 cM. The genome of each IL harbored the chromosomal fragments of O. rufipogon ranging from 0.54% to 23.7%, with an overall average of 5.79%. At each locus, the ratio of substitution of O. rufipogon alleles had a range of 1.67-9.33, with an average of 5.50. A wide range of alterations in morphological and yield-related traits were also found in the introgression lines population. Using single-point analysis, a total of 37 putative QTLs for yield and yield components were detected at two sites with 7%-20% explaining the phenotypic variance. Nineteen QTLs （51.4%） were detected at both sites, and the alleles from O. rufipogon at fifteen loci （40.5%） improved the yield and yield components in the Teqing background. These O. rufipogon-O, sativa introgression lines will serve as genetic materials for identifying and using favorable genes from common wild rice.展开更多
Soil salinity is one of the major abiotic stresses affecting plant growth and crop production.In the present study,salt tolerance at rice seedling stage was evaluated using 87 introgression lines（ILs）,which were der...Soil salinity is one of the major abiotic stresses affecting plant growth and crop production.In the present study,salt tolerance at rice seedling stage was evaluated using 87 introgression lines（ILs）,which were derived from a cross between an elite indica cultivar Teqing and an accession of common wild rice（Oryza rufipogon Griff.）.Substantial variation was observed for four traits including salt tolerance score（STS）, relative root dry weight（RRW）,relative shoot dry weight（RSW） and relative total dry weight（RTW）.STS was significantly positively correlated with all other three traits.A total of 15 putative quantitative trait loci（QTLs） associated with these four traits were detected using single-point analysis,which were located on chromosomes 1,2,3,6,7,9 and 10 with 8%-26%explaining the phenotypic variance.The O. rufipogon-derived alleles at 13 QTLs（86.7%） could improve the salt tolerance in the Teqing background.Four QTL clusters affecting RRW, RSW and RTW were found on chromosomes 6,7,9 and 10,respectively.Among these four QTL clusters,a major cluster including three QTLs （qRRWIO,qRSWIO and qRTWIO） was found near the maker RM271 on the long arm of chromosome 10,and the O.rufipogon-derived alleles at these three loci increased RRW,RSW and RTW with additive effects of 22.7%,17.3%and 18.5%,respectively,while the phenotypic variance explained by these three individual QTLs for the three traits varied from 19%to 26%.In addition,several salt tolerant ILs were selected and could be used for identifying and utilizing favorable salt tolerant genes from common wild rice and used in the salt tolerant rice breeding program.展开更多
Many different types of buildings were severely damaged or collapsed during the May 12, 2008 Great Wenchuan Earthquake. Based on survey data collected in regions that were subjected to moderate to severe earthquake in...Many different types of buildings were severely damaged or collapsed during the May 12, 2008 Great Wenchuan Earthquake. Based on survey data collected in regions that were subjected to moderate to severe earthquake intensities, a comparison between the observed building damage, and the three earthquake performance objectives and seismic conceptual design principles specified by the national ＂Code for Seismic Design of Buildings GB50011-2001,＂ was carried out. Actual damage and predicted damage for a given earthquake level for different types of structures is compared. Discussions on seismic conceptual design principles, with respect to multiple defense lines, strong column-weak beam, link beam of shear walls, ductility detailing of masonry structures, exits and staircases, and nonstructural elements, etc. are carried out. Suggestions for improving the seismic design of structures are also proposed. It is concluded that the seismic performance objectives for three earthquake levels, i.e., ＂no failure under minor earthquake level, ＂＂repairable damage under moderate earthquake level＂ and ＂no collapse under major earthquake level＂ can be achieved if seismic design principles are carried out by strictly following the code requirements and ensuring construction quality.展开更多
Grain yield is one of the most important indexes in rice breeding, which is governed by quantitative trait loci （QTLs）. Different map- ping populations have been used to explore the QTLs controlling yield related tr...Grain yield is one of the most important indexes in rice breeding, which is governed by quantitative trait loci （QTLs）. Different map- ping populations have been used to explore the QTLs controlling yield related traits. Primary populations such as F2 and recombi- nant inbred line populations have been widely used to discover QTLs in rice genome-wide, with hundreds of yield-related QTLs detected. Advanced populations such as near isogenic lines （NILs） are efficient to further fine-map and clone target QTLs. NILs for primarily identified QTLs have been proposed and confirmed to be the ideal population for map-based cloning. To date, 20 QTLs directly affecting rice grain yield and its components have been cloned with NIL-F2 populations, and 14 new grain yield QTLs havebeen validated in the NILs. The molecular mechanisms＇of＇a continuous/y increasing number of genes are being unveiled, which aids in the understanding of the formation of grain yield. Favorable alleles for rice breeding have been ＇mined＇ from natural cultivars and wild rice by association analysis of known functional genes with target trait performance. Reasonable combination of favorable alleles has the potential to increase grain yield via use of functional marker assisted selection.展开更多
Eight indica ( Oryza sativa L.) environment-sensitive genic male-sterile (EGMS) lines, 2-2S, K1405S, F131S, 2136S, Pei-Ai 64S, 1290S, GD-IS and N17S, were sequentially seeded with 10-15 d interval at three sites, Wuha...Eight indica ( Oryza sativa L.) environment-sensitive genic male-sterile (EGMS) lines, 2-2S, K1405S, F131S, 2136S, Pei-Ai 64S, 1290S, GD-IS and N17S, were sequentially seeded with 10-15 d interval at three sites, Wuhan in 1997, Guiyang in 1997 and Sanya in 1997 and 1998, China. The results of investigations on self-sterilities showed that all of eight EGMS lines had stable sterile periods of longer than 30 d at Wuhan. They can be used for seed production of two-line hybrid rice, but can not reproduce themselves. Their stable sterile periods were shorter than 30 d at Guiyang, they can reproduce themselves and can not be used for hybrid seed production. In Sanya, their stable sterile periods were longer than 150 d, all of eight lines can be used for seed production in summer and autumn and reproduce themselves in winter. The fertility of all eight lines were sensitive to temperature. The sensitive stages, sensitive duration and critical point of temperatures (CPT) of fertility alteration in various lines were different. The sensitive stages of 2-2S and K1405S were from 18 d to 9 d before heading, the sensitive durations were 7-10 d and the CPTs were 23.7-24.5 degreesC. The sensitive stage, sensitive duration and CPT of F131S were from 17 to 5 d before heading, 13 d and 24.3-24.7 degreesC, respectively. The sensitive stage, sensitive duration and CPT of 2136S were from 18 to 12 d before heading, 7 d and 24.6-25.1 degreesC:, respectively. The sensitive stages, sensitive durations of Pei-Ai 64S, 1290S, N17S and GD-1S were from 24 to 13 d before heading and 10-13 d. And their CPTs were 24.6-25.1 degreesC, 25.5-26.2 degreesC, 25.4-26.1 degreesC,, and 24.1-24.7 degreesC, respectively.展开更多
Obejctive To detect the influence of antisense s oligodeoxynucleotides (S ODNs) of bd 2 and multidrug resistamce associated protein (MRP) genes multidrug resistance associated protein gene and bcl 2 antisen...Obejctive To detect the influence of antisense s oligodeoxynucleotides (S ODNs) of bd 2 and multidrug resistamce associated protein (MRP) genes multidrug resistance associated protein gene and bcl 2 antisense S oligodeoxynucleotides on cisplatin resistant lung adenocarcinoma cell line A 549 DDP which overexpresses both bcl 2 and MRP Methods A 549 DDP cells were treated with sense and antisense S ODN mediated by lipofection Expression of MRP and bcl 2 mRNA and protein in the treated cells was measured by RT PCR and flow cytometry (FCM), respectively Apoptosis was identified by DNA electrophoresis and terminal deoxynucleotidyl transferase (TdT) mediated biotin dUTP nick end labeling(TUNEL) The degree of drug resistance of the treated cells was detected by a cell viability 3' [4,5 dimethylthiazol 2 yl] 2,5 diphenyl tefrazolium bromide thiazolylblue (MTT) assay Results Expression of bcl 2 and MRP significantly decreased in the cells treated with bcl 2 or/and MRP antisense S ODN for 48h as compared to the cells untreated and sense treated ( P <0 05) Resistance to cisplatin in the cells treated with bcl 2 or/and MRP antisense S ODN decreased by 60 6% (6 5 times), 56 4% (7 2 times) and 71 0% (4 8 times), respectively, which paralleled the decrease of bcl 2 and MRP expression Similarly, the resistance to etoposide and epirubicin in antisense treated cells also reduced in parallel to decreases of the two gene expressions The drug resistance in sense treated cells was similar to that in untreated cells Statistically significant dose and concentration dependent increases of apoptotic cells were observed in the groups exposed to 100?μmol/L cisplatin for 48?h after treatment by bcl 2 or/and MRP antisense Conclusion Bcl 2 and MRP were at least additive and possibly synergistic in conferring drug resistance in a cisplatin resistant lung adenocarcinoma cell line Antisense S ODN could attenuate drug resistance by promoting cells apopto展开更多
Six core issues for vortex definition and identification concern with (1) the absolute strength,(2) the relative strength,(3) the rotational axis,(4) the vortex core center,(5) the vortex core size, and (6) the vortex...Six core issues for vortex definition and identification concern with (1) the absolute strength,(2) the relative strength,(3) the rotational axis,(4) the vortex core center,(5) the vortex core size, and (6) the vortex boundary (Liu C. 2019). However, most of the currently popular vortex identification methods, including the Q criterion, the criterion and the Acj criterion etc., are Eulerian local region-type vortex identification criteria and can only approximately identify the vortex boundary by somewhat arbitrary threshold. On the other hand, the existing Eulerian local line-type methods, which seek to extract line-type features such as vortex core line, are not entirely satisfactory since most of these methods are based on vorticity or pressure minimum that will fail in many cases. The key issue is the lack of a reasonable mathematical definition for vortex core center. To address this issue, a Liutex (previously named Rortex) based definition of vortex core center is proposed in this paper. The vortex core center, also called vortex rotation axis line here, is defined as a line where the Liutex magnitude gradient vector is aligned with the Liutex vector, which mathematically implies that the cross product of the Liutex magnitude gradient vector and the Liutex vector on the line is equal to zero. Based on this definition, a novel three-step method for extracting vortex rotation axis lines is presented. Two test cases, namely the Burgers vortex and hairpin vortices, are examined to justify the proposed method. The results demonstrate that the proposed method can successfully identify vortex rotation axis lines without any user-specified threshold, so that the proposed method is very straightforward, robust and efficient.展开更多
INTRODUCTIONVascular endothelial growth factor(VEGF)whichis also known as vascular permeability factor(VPF)is a heparin-binding,dimeric polypeptide growthfactor and a potent mitogen for endothelial cells.VEGF can stim...INTRODUCTIONVascular endothelial growth factor(VEGF)whichis also known as vascular permeability factor(VPF)is a heparin-binding,dimeric polypeptide growthfactor and a potent mitogen for endothelial cells.VEGF can stimulate the endothelial cell growth andenhance the motility through its two knownreceptors flt-1 and KDR.Acting through thesereceptors,VEGF may stimulate angiogenesis展开更多
This paper presents results of model tests for the landslide dam failure of a single dam and cascade dams in a sloping channel. The dams were designed to be regular trapezoid with fine sand. A new measuring method nam...This paper presents results of model tests for the landslide dam failure of a single dam and cascade dams in a sloping channel. The dams were designed to be regular trapezoid with fine sand. A new measuring method named the labeled line locating method was used to digitalize the captured instantaneous pictures. Under two different inflow discharges, the morphological evolution and the flow patterns during one dam failure and the failure of cascade dams were investigated. The results indicate that when the inflow discharge is large, the deformation pattern of the downstream dam is similar to that of the upstream dam, and both dams are characterized with the overtopping scour throughout the dam failure process. When the inflow discharge is small, the upstream dam is scoured mainly through a sluice slot formed by the longitudinal incision, and the downstream dam is characterized with the overtopping scour. The data set presented in this paper can be used for the validation of numerical models and provide a reference for the flood risk management of cascade landslide dams.展开更多
AIM: In order to obtain lymphogenous metastasisassociated genes, we compared the transcriptional profiles of mouse hepatocarcinoma cell lines Hca-F with highly lymphatic metastasis potential and Hca-P with low lymphat...AIM: In order to obtain lymphogenous metastasisassociated genes, we compared the transcriptional profiles of mouse hepatocarcinoma cell lines Hca-F with highly lymphatic metastasis potential and Hca-P with low lymphatic metastasis potential.METHODS: Total RNA was isolated from Hca-F and Hca-P cells and synthesized into double-stranded cDNA. In vitro transcription double-stranded cDNA was labeled with biotin (i.e. biotin-labeled cRNA, used as the probe). The cRNA probes hybridized with Affymetrix GeneChip() MOE430A (containing 22 690 transcripts, including 14 500 known mouse genes and 4 371 ESTs) respectively and the signals were scanned by the GeneArray Scanner. The results were then analyzed by bioinformatics.RESULTS: Out of the 14 500 known genes investigated,110 (0.8%) were up regulated at least 23 fold. Among the total 4 371 ESTs, 17 ESTs (0.4%) (data were not presented) were up regulated at least 23 fold. According to the Gene Ontology and TreeView analysis, the 110genes were further classified into two groups: differential biological process profile and molecular function profile.CONCLUSION: Using high-throughput gene chip method,a large number of genes and their cellular functions about angiogenesis, cell adhesion, signal transduction, cell motility, transport, microtubule-based process, cytoskeleton organization and biogenesis, cell cycle, transcription,chaperone activity, motor activity, protein kinase activity,receptor binding and protein binding might be involved in the process of lymphatic metastasis and deserve to be used as potential candidates for further investigation.Cyclin D1, Fosl1, Hsp47, EGFR and AR, and Cav-1 are selected as the possible candidate genes of the metastatic phenotype, which need to be validated in later experiments.ESTs (data were not presented) might indicate novel genes associated with lymphatic metastasis. Validating the function of these genes is helpful to identify the key or candidate gene/pathway responsible for lymphatic metastasis, which might be used as the diagnostic展开更多
In present study, Fe, Zn, Mn, Cu, Ca, Mg, P and K contents of 85 introgression lines （ILs） derived from a cross between an elite indica cultivar Teqing and the wild rice （Oryza rufipogon） were measured by inductiv...In present study, Fe, Zn, Mn, Cu, Ca, Mg, P and K contents of 85 introgression lines （ILs） derived from a cross between an elite indica cultivar Teqing and the wild rice （Oryza rufipogon） were measured by inductively coupled argon plasma （ICAP） spectrometry. Substantial variation was observed for all traits and most of the mineral elements were significantly positive correlated or independent except for Fe with Cu. A total of 31 putative quantitative trait loci （QTLs） were detected for these eight mineral elements by single point analysis. Wild rice （O. rufipogon） contributed favorable alleles for most of the QTLs （26 QTLs）, and chromosomes 1,9 and 12 exhibited 14 QTLs （45%） for these traits. One major effect of QTL for zinc content accounted for the largest proportion of phenotypic variation （11%-19%） was detected near the simple sequence repeats marker RM152 on chromosome 8. The co-locations of QTLs for some mineral elements observed in this mapping population suggested the relationship was at a molecular level among these traits and could be helpful for simultaneous improvement of these traits in rice grain by marker assisted selection.展开更多
文摘Rice yield and heading date are two distinct traits controlled by quantitative trait loci （QTLs）. The dissection of molecular mechanisms underlying rice yield traits is important for developing high-yielding rice varieties. Here, we report the cloning and characterization of Ghd8, a major QTL with pleiotropic effects on grain yield, heading date, and plant height. Two sets of near isogenic line populations were developed for the cloning of GhdS. Ghd8 was narrowed down to a 20-kb region containing two putative genes, of which one encodes the OsHAP3 subunit of a CCAAT-box binding protein （HAP complex）; this gene was regarded as the Ghd8 candidate. A complementary test confirmed the identity and pleiotropic effects of the gene; interestingly, the genetic effect of Ghd8 was dependent on its genetic background. By regulating Ehdl, RFT1, and Hd3a, Ghd8 delayed flowering under long-day conditions, but promoted flowering under short-day conditions. Ghd8 up-regulated MOC1, a key gene controlling tillering and branching; this increased the number of tillers, primary and secondary branches, thus producing 50% more grains per plant. The ectopic expression of Ghd8 in Arabidopsis caused early flowering by 10 d-a situation similar to the one observed by its homolog AtHAP3b, when compared to wild-type under long-day conditions; these findings indicate the conserved function of Ghd8 and AtHAP3b in flowering in Arabidopsis. Our results demonstrated the important roles of Ghd8 in rice yield formation and flowering, as well as its opposite functions in flowering between rice and Arabidopsis under long-day conditions.
基金This work was supported in part by National Natural Science Foundation of China(No.30170413)the Foundation for Jing Yuan FANG of National Excellent Doctoral Dissertation of China(No.199946)the Foundation of Shanghai Education Committee(Shuguang Plan,No.02SG45).
文摘The aim of this study is to assess the effects of DNA methylation and historic acetylation, alone or in combination, on the expression of several tumor-associated genes and cell cycle progression in two established human colon cancer cell lines: Colo-320 and SW1116. Treatments with 5-aza-2'-deoxycytidine (5-aza-dC) and trichostatin A, alone or in combination, were applied respectively. The methylation status of the CDKN2A promoter was determined by methyla-tion-specific PCR, and the acetylated status of the histones associated with the p21WAF1 and CDKN2A genes was examined by chromatin immunoprecipitation. The expression of the CDKN2A, p21WAF1, p53, p73, APC, c-myc, c-Ki-ras and survivin genes was detected by real-time RT-PCR and RT-PCR. The cell cycle profile was established by flow cytometry. We found that along with the demethylation of the CDKN2A gene promoter in both cell lines induced by 5-aza-dC alone or in combination with TSA, the expression of both CDKN2A and APC genes increased. The treatment of TSA or sodium butyrate up-regulated the transcription of p21WAF1 significantly by inducing the acetylation of histones H4 and H3, but failed to alter the acetylation level of CDKN2A-associated histones. No changes in transcription of p53, p73, c-myc, c-Ki-ras and survivin genes were observed. In addition, TSA or sodium butyrate was shown to arrest cells at the G1 phase. However, 5-aza-dC was not able to affect the cell cycle progression. In conclusion, regulation by epigenetic modification of the transcription of tumor-associated genes and the cell cycle progression in both human colon cancer cell lines Colo-320 and SW1116 is gene-specific.
基金supported by the grant of the National High Technology Research and Development Program("863"Program)of China(No.2011AA100101)
文摘Thinopyrum elongatum （2n = 2x = 14, EE）, a wild relative of wheat, has been suggested as a potentially novel source of resistance to several major wheat diseases including Fusarium Head Blight （FHB）. In this study, a series of wheat （cv. Chinese Spring, CS） substitution and ditelosomic lines, including Th. elongatum additions, were assessed for Type II resistance to FHB. Results indicated that the lines containing chromosome 7E of Th. elongatum gave a high level of resistance to FHB, wherein the infection did not spread beyond the inoculated floret. Furthermore, it was determined that the novel resistance gene（s） of 7E was located on the short-ann （7ES） based on sharp difference in FHB resistance between the two 7E ditelosomic lines for each arm. On the other hand, Th. elongatum chromosomes 5E and 6E likely contain gene（s） for susceptibility to FHB because the disease spreads rapidly within the inoculated spikes of these lines. Genomic in situ hybridization （GISH） analysis revealed that the alien chromosomes in the addition and substitution lines were intact, and the lines did not contain discernible genomic aberrations. GISH and multicolor-GISH analyses were further performed on three trans- location lines that also showed high levels of resistance to FHB. Lines TA3499 and TA3695 were shown to contain one pair of wheat-Th. elongatum translocated chromosomes involving fragments of 7D plus a segment of the 7E, while line TA3493 was found to contain one pair of wheat-Th, elongatum translocated chromosomes involving the D- and A-genome chromosomes of wheat. Thus, this study has established that the short-arm of chromosome 7E of Th. elongatum harbors gene（s） highly resistant to the spreading of FHB, and chromatin of 7E introgressed into wheat chromosomes largely retained the resistance, implicating the feasibility of using these lines as novel material for breeding FHB-resistant wheat cultivars.
基金Supported by the Project of Conservation and Utilization of Agricultural Wild Plants of the Ministry of Agriculture of China and a Grant from High- Tech Research and Development （863） Program of China （2006AA100101 ）, and the National Natural Science Foundation of China （30270803）. Publication of this paper is supported by the National Natural Science Foundation of China （30624808）.
文摘Introgression lines population was effectively used in mapping quantitative trait loci （QTLs）, identifying favorable genes, discovering hidden genetic variation, evaluating the action or interaction of QTLs in multiple conditions and providing the favorable experimental materials for plant breeding and genetic research. In this study, an advanced backcross and consecutive selfing strategy was used to develop introgression lines （ILs）, which derived from an accession of Oryza rufipogon Griff. collected from Yuanjiang County, Yunnan Province of China, as the donor, and an elite indica cultivar Teqing （O. sativa L.）, as the recipient. Introgression segments from O. rufipogon were screened using 179 polymorphic simple sequence repeats （SSR） markers in the genome of each IL. Introgressed segments carried by the introgression lines population contained 120 ILs covering the whole O. rufipogon genome. The mean number of homozygous O. rufipogon segments per introgression line was about 3.88. The average length of introgressed segments was approximate 25.5 cM, and about 20.8% of these segments had sizes less than 10 cM. The genome of each IL harbored the chromosomal fragments of O. rufipogon ranging from 0.54% to 23.7%, with an overall average of 5.79%. At each locus, the ratio of substitution of O. rufipogon alleles had a range of 1.67-9.33, with an average of 5.50. A wide range of alterations in morphological and yield-related traits were also found in the introgression lines population. Using single-point analysis, a total of 37 putative QTLs for yield and yield components were detected at two sites with 7%-20% explaining the phenotypic variance. Nineteen QTLs （51.4%） were detected at both sites, and the alleles from O. rufipogon at fifteen loci （40.5%） improved the yield and yield components in the Teqing background. These O. rufipogon-O, sativa introgression lines will serve as genetic materials for identifying and using favorable genes from common wild rice.
基金supported by the Project of Conservation and Utilization of Agro-Wild Plants of the Ministry of Agriculture of China and Special Fund for Agro-scientific Research in the Public Interest(No.201003021)
文摘Soil salinity is one of the major abiotic stresses affecting plant growth and crop production.In the present study,salt tolerance at rice seedling stage was evaluated using 87 introgression lines（ILs）,which were derived from a cross between an elite indica cultivar Teqing and an accession of common wild rice（Oryza rufipogon Griff.）.Substantial variation was observed for four traits including salt tolerance score（STS）, relative root dry weight（RRW）,relative shoot dry weight（RSW） and relative total dry weight（RTW）.STS was significantly positively correlated with all other three traits.A total of 15 putative quantitative trait loci（QTLs） associated with these four traits were detected using single-point analysis,which were located on chromosomes 1,2,3,6,7,9 and 10 with 8%-26%explaining the phenotypic variance.The O. rufipogon-derived alleles at 13 QTLs（86.7%） could improve the salt tolerance in the Teqing background.Four QTL clusters affecting RRW, RSW and RTW were found on chromosomes 6,7,9 and 10,respectively.Among these four QTL clusters,a major cluster including three QTLs （qRRWIO,qRSWIO and qRTWIO） was found near the maker RM271 on the long arm of chromosome 10,and the O.rufipogon-derived alleles at these three loci increased RRW,RSW and RTW with additive effects of 22.7%,17.3%and 18.5%,respectively,while the phenotypic variance explained by these three individual QTLs for the three traits varied from 19%to 26%.In addition,several salt tolerant ILs were selected and could be used for identifying and utilizing favorable salt tolerant genes from common wild rice and used in the salt tolerant rice breeding program.
文摘Many different types of buildings were severely damaged or collapsed during the May 12, 2008 Great Wenchuan Earthquake. Based on survey data collected in regions that were subjected to moderate to severe earthquake intensities, a comparison between the observed building damage, and the three earthquake performance objectives and seismic conceptual design principles specified by the national ＂Code for Seismic Design of Buildings GB50011-2001,＂ was carried out. Actual damage and predicted damage for a given earthquake level for different types of structures is compared. Discussions on seismic conceptual design principles, with respect to multiple defense lines, strong column-weak beam, link beam of shear walls, ductility detailing of masonry structures, exits and staircases, and nonstructural elements, etc. are carried out. Suggestions for improving the seismic design of structures are also proposed. It is concluded that the seismic performance objectives for three earthquake levels, i.e., ＂no failure under minor earthquake level, ＂＂repairable damage under moderate earthquake level＂ and ＂no collapse under major earthquake level＂ can be achieved if seismic design principles are carried out by strictly following the code requirements and ensuring construction quality.
基金supported by grants from the National Natural Science Foundation of China (30921091,30830064)the National Special Program for Research of Transgenic Plants of China (2009ZX08009-103B)+1 种基金the National Program on the Development of Basic Research (2010CB125901)the National Special Key Project of China on Functional Genomics of Major Plants and Animals (2012AA100103)
文摘Grain yield is one of the most important indexes in rice breeding, which is governed by quantitative trait loci （QTLs）. Different map- ping populations have been used to explore the QTLs controlling yield related traits. Primary populations such as F2 and recombi- nant inbred line populations have been widely used to discover QTLs in rice genome-wide, with hundreds of yield-related QTLs detected. Advanced populations such as near isogenic lines （NILs） are efficient to further fine-map and clone target QTLs. NILs for primarily identified QTLs have been proposed and confirmed to be the ideal population for map-based cloning. To date, 20 QTLs directly affecting rice grain yield and its components have been cloned with NIL-F2 populations, and 14 new grain yield QTLs havebeen validated in the NILs. The molecular mechanisms＇of＇a continuous/y increasing number of genes are being unveiled, which aids in the understanding of the formation of grain yield. Favorable alleles for rice breeding have been ＇mined＇ from natural cultivars and wild rice by association analysis of known functional genes with target trait performance. Reasonable combination of favorable alleles has the potential to increase grain yield via use of functional marker assisted selection.
文摘Eight indica ( Oryza sativa L.) environment-sensitive genic male-sterile (EGMS) lines, 2-2S, K1405S, F131S, 2136S, Pei-Ai 64S, 1290S, GD-IS and N17S, were sequentially seeded with 10-15 d interval at three sites, Wuhan in 1997, Guiyang in 1997 and Sanya in 1997 and 1998, China. The results of investigations on self-sterilities showed that all of eight EGMS lines had stable sterile periods of longer than 30 d at Wuhan. They can be used for seed production of two-line hybrid rice, but can not reproduce themselves. Their stable sterile periods were shorter than 30 d at Guiyang, they can reproduce themselves and can not be used for hybrid seed production. In Sanya, their stable sterile periods were longer than 150 d, all of eight lines can be used for seed production in summer and autumn and reproduce themselves in winter. The fertility of all eight lines were sensitive to temperature. The sensitive stages, sensitive duration and critical point of temperatures (CPT) of fertility alteration in various lines were different. The sensitive stages of 2-2S and K1405S were from 18 d to 9 d before heading, the sensitive durations were 7-10 d and the CPTs were 23.7-24.5 degreesC. The sensitive stage, sensitive duration and CPT of F131S were from 17 to 5 d before heading, 13 d and 24.3-24.7 degreesC, respectively. The sensitive stage, sensitive duration and CPT of 2136S were from 18 to 12 d before heading, 7 d and 24.6-25.1 degreesC:, respectively. The sensitive stages, sensitive durations of Pei-Ai 64S, 1290S, N17S and GD-1S were from 24 to 13 d before heading and 10-13 d. And their CPTs were 24.6-25.1 degreesC, 25.5-26.2 degreesC, 25.4-26.1 degreesC,, and 24.1-24.7 degreesC, respectively.
文摘Obejctive To detect the influence of antisense s oligodeoxynucleotides (S ODNs) of bd 2 and multidrug resistamce associated protein (MRP) genes multidrug resistance associated protein gene and bcl 2 antisense S oligodeoxynucleotides on cisplatin resistant lung adenocarcinoma cell line A 549 DDP which overexpresses both bcl 2 and MRP Methods A 549 DDP cells were treated with sense and antisense S ODN mediated by lipofection Expression of MRP and bcl 2 mRNA and protein in the treated cells was measured by RT PCR and flow cytometry (FCM), respectively Apoptosis was identified by DNA electrophoresis and terminal deoxynucleotidyl transferase (TdT) mediated biotin dUTP nick end labeling(TUNEL) The degree of drug resistance of the treated cells was detected by a cell viability 3' [4,5 dimethylthiazol 2 yl] 2,5 diphenyl tefrazolium bromide thiazolylblue (MTT) assay Results Expression of bcl 2 and MRP significantly decreased in the cells treated with bcl 2 or/and MRP antisense S ODN for 48h as compared to the cells untreated and sense treated ( P <0 05) Resistance to cisplatin in the cells treated with bcl 2 or/and MRP antisense S ODN decreased by 60 6% (6 5 times), 56 4% (7 2 times) and 71 0% (4 8 times), respectively, which paralleled the decrease of bcl 2 and MRP expression Similarly, the resistance to etoposide and epirubicin in antisense treated cells also reduced in parallel to decreases of the two gene expressions The drug resistance in sense treated cells was similar to that in untreated cells Statistically significant dose and concentration dependent increases of apoptotic cells were observed in the groups exposed to 100?μmol/L cisplatin for 48?h after treatment by bcl 2 or/and MRP antisense Conclusion Bcl 2 and MRP were at least additive and possibly synergistic in conferring drug resistance in a cisplatin resistant lung adenocarcinoma cell line Antisense S ODN could attenuate drug resistance by promoting cells apopto
基金supported by the National Natural Science Foundation of China (Grant No. 91530325).
文摘Six core issues for vortex definition and identification concern with (1) the absolute strength,(2) the relative strength,(3) the rotational axis,(4) the vortex core center,(5) the vortex core size, and (6) the vortex boundary (Liu C. 2019). However, most of the currently popular vortex identification methods, including the Q criterion, the criterion and the Acj criterion etc., are Eulerian local region-type vortex identification criteria and can only approximately identify the vortex boundary by somewhat arbitrary threshold. On the other hand, the existing Eulerian local line-type methods, which seek to extract line-type features such as vortex core line, are not entirely satisfactory since most of these methods are based on vorticity or pressure minimum that will fail in many cases. The key issue is the lack of a reasonable mathematical definition for vortex core center. To address this issue, a Liutex (previously named Rortex) based definition of vortex core center is proposed in this paper. The vortex core center, also called vortex rotation axis line here, is defined as a line where the Liutex magnitude gradient vector is aligned with the Liutex vector, which mathematically implies that the cross product of the Liutex magnitude gradient vector and the Liutex vector on the line is equal to zero. Based on this definition, a novel three-step method for extracting vortex rotation axis lines is presented. Two test cases, namely the Burgers vortex and hairpin vortices, are examined to justify the proposed method. The results demonstrate that the proposed method can successfully identify vortex rotation axis lines without any user-specified threshold, so that the proposed method is very straightforward, robust and efficient.
基金National Distinguished Young Scientist Fund,39525021 State Key Basic Research Program G1998051203
文摘INTRODUCTIONVascular endothelial growth factor(VEGF)whichis also known as vascular permeability factor(VPF)is a heparin-binding,dimeric polypeptide growthfactor and a potent mitogen for endothelial cells.VEGF can stimulate the endothelial cell growth andenhance the motility through its two knownreceptors flt-1 and KDR.Acting through thesereceptors,VEGF may stimulate angiogenesis
基金supported by the National Basic Research and Development Program of China(973 Program,Grant No.2007CB714105)the National Natural Science Foundation of China(Grant No.50909067)
文摘This paper presents results of model tests for the landslide dam failure of a single dam and cascade dams in a sloping channel. The dams were designed to be regular trapezoid with fine sand. A new measuring method named the labeled line locating method was used to digitalize the captured instantaneous pictures. Under two different inflow discharges, the morphological evolution and the flow patterns during one dam failure and the failure of cascade dams were investigated. The results indicate that when the inflow discharge is large, the deformation pattern of the downstream dam is similar to that of the upstream dam, and both dams are characterized with the overtopping scour throughout the dam failure process. When the inflow discharge is small, the upstream dam is scoured mainly through a sluice slot formed by the longitudinal incision, and the downstream dam is characterized with the overtopping scour. The data set presented in this paper can be used for the validation of numerical models and provide a reference for the flood risk management of cascade landslide dams.
基金Supported by the National Natural Science Foundation of China,No. 30371583
文摘AIM: In order to obtain lymphogenous metastasisassociated genes, we compared the transcriptional profiles of mouse hepatocarcinoma cell lines Hca-F with highly lymphatic metastasis potential and Hca-P with low lymphatic metastasis potential.METHODS: Total RNA was isolated from Hca-F and Hca-P cells and synthesized into double-stranded cDNA. In vitro transcription double-stranded cDNA was labeled with biotin (i.e. biotin-labeled cRNA, used as the probe). The cRNA probes hybridized with Affymetrix GeneChip() MOE430A (containing 22 690 transcripts, including 14 500 known mouse genes and 4 371 ESTs) respectively and the signals were scanned by the GeneArray Scanner. The results were then analyzed by bioinformatics.RESULTS: Out of the 14 500 known genes investigated,110 (0.8%) were up regulated at least 23 fold. Among the total 4 371 ESTs, 17 ESTs (0.4%) (data were not presented) were up regulated at least 23 fold. According to the Gene Ontology and TreeView analysis, the 110genes were further classified into two groups: differential biological process profile and molecular function profile.CONCLUSION: Using high-throughput gene chip method,a large number of genes and their cellular functions about angiogenesis, cell adhesion, signal transduction, cell motility, transport, microtubule-based process, cytoskeleton organization and biogenesis, cell cycle, transcription,chaperone activity, motor activity, protein kinase activity,receptor binding and protein binding might be involved in the process of lymphatic metastasis and deserve to be used as potential candidates for further investigation.Cyclin D1, Fosl1, Hsp47, EGFR and AR, and Cav-1 are selected as the possible candidate genes of the metastatic phenotype, which need to be validated in later experiments.ESTs (data were not presented) might indicate novel genes associated with lymphatic metastasis. Validating the function of these genes is helpful to identify the key or candidate gene/pathway responsible for lymphatic metastasis, which might be used as the diagnostic
基金Supported by the Project of Conservation and Utilization of AgriculturalWild Plants of the Ministry of Agriculture of Chinathe National High-TechResearch and Development ("863") Program of China (2006AA100101)the National Natural Science Foundation of China (30771319).
文摘In present study, Fe, Zn, Mn, Cu, Ca, Mg, P and K contents of 85 introgression lines （ILs） derived from a cross between an elite indica cultivar Teqing and the wild rice （Oryza rufipogon） were measured by inductively coupled argon plasma （ICAP） spectrometry. Substantial variation was observed for all traits and most of the mineral elements were significantly positive correlated or independent except for Fe with Cu. A total of 31 putative quantitative trait loci （QTLs） were detected for these eight mineral elements by single point analysis. Wild rice （O. rufipogon） contributed favorable alleles for most of the QTLs （26 QTLs）, and chromosomes 1,9 and 12 exhibited 14 QTLs （45%） for these traits. One major effect of QTL for zinc content accounted for the largest proportion of phenotypic variation （11%-19%） was detected near the simple sequence repeats marker RM152 on chromosome 8. The co-locations of QTLs for some mineral elements observed in this mapping population suggested the relationship was at a molecular level among these traits and could be helpful for simultaneous improvement of these traits in rice grain by marker assisted selection.
