RAV1 is a novel DNA-binding protein with two distinct DNA-binding domains unique in higher plants,but its role in plant growth and development remains unknown. Using cDNA array,we found that transcription of RAV1 is d...RAV1 is a novel DNA-binding protein with two distinct DNA-binding domains unique in higher plants,but its role in plant growth and development remains unknown. Using cDNA array,we found that transcription of RAV1 is downregulated by epibrassinolide (epiBL) in Arabidopsis suspension cells. RNA gel blot analysis revealed that epiBL-regulated RAV1 transcription involves neither protein phosphorylation/dephosphorylation nor newly synthesized protein,and does not require the functional BRI1,suggesting that this regulation might be through a new BR signaling pathway.Overexpressing RAV1 in Arabidopsis results in a retardation of lateral root and rosette leaf development,and the underexpression causes an earlier flowering phenotype,implying that RAV1 may function as a negative regulatory component of growth and development.展开更多
AIM:To examine the role of nucleostemin in the growth regulation of gastric cancer,liver cancer and other cancers.METHODS:RT-PCR was used to clone the fragment of nucleostemin cDNA from HEK 293 cells.Eighteen kinds of...AIM:To examine the role of nucleostemin in the growth regulation of gastric cancer,liver cancer and other cancers.METHODS:RT-PCR was used to clone the fragment of nucleostemin cDNA from HEK 293 cells.Eighteen kinds of malignant tumor tissues including gastric adenocarcinoma and liver cancer tissues,3 kinds of benign tumor tissues,3 kinds of benign hyperplastic tissues and normal tissues were employed to examine nucleostemin gene expression by RT-PCR,Slot blot,Northern blot and in situ hybridization.RESULTS:We successfully cloned a 570 bp fragment of nucleostemin-cDNA from HEK-293 cells.All edtected malignant tumor tissues,benign tumor tissues,and benign hyperplastic tissues had hign levels of nucleostemin expression.Nucleostemin was also expressed in human placenta tissue at a high levle.In terminally differentiated normal human adult kidney and mammary gland tissues,no nucleostemin expression could be detected.CONCLUSION:Nucleostemin can help regulate the proliferation of both cancer cells and stem cells.It might play an important role in the growth regulation of gastric cancer,liver cancer and other cancers.展开更多
Ammonia (NH3) volatilization, denitrification loss, and nitrous oxide (N2O) emission were investigated from an irrigated wheat-maize rotation field on the North China Plain, and the magnitude of gaseous N loss from de...Ammonia (NH3) volatilization, denitrification loss, and nitrous oxide (N2O) emission were investigated from an irrigated wheat-maize rotation field on the North China Plain, and the magnitude of gaseous N loss from denitrification and NH3 volatilization was assessed. The micrometeorological gradient diffusion method in conjunction with a Bowen Ratio system was utilized to measure actual NH3 fluxes over a large area, while the acetylene inhibition technique (intact soil cores) was employed for measurement of denitrification losses and N2O emissions. Ammonia volatilization loss was 26.62% of the applied fertilizer nitrogen (N) under maize, while 0.90% and 15.55% were lost from the wheat field at sowing and topdressing, respectively. The differences in NH3 volatilization between different measurement events may be due to differences between the fertilization methods, and to differences in climatic conditions such as soil temperature.Denitrification losses in the fertilized plots were 0.67%-2.87% and 0.31%-0.49% of the applied fertilizer N under maize and wheat after subtracting those of the controls, respectively. Nitrous oxide emissions in the fertilized plots were approximately 0.08%-0.41% and 0.26%-0.34% of the applied fertilizer N over the maize and wheat seasons after subtracting those of the controls, correspondingly. The fertilizer N losses due to NH3 volatilization were markedly higher than those through denitrification and nitrous oxide emissions. These results indicated that NH3 volatilization was an important N transformation in the crop-soil system and was likely to be the major cause of low efficiencies with N fertilizer in the study area. Denitrification was not a very important pathway of N fertilizer loss, but did result in important evolution of the greenhouse gas N2O and the effect of N2O emitted from agricultural fields on environment should not be overlooked.展开更多
This paper reports the cloning and expression analysis of a high-affinity nitrate transporter inwheat ( Triticurn aestivurn L.). A full-length cDNA, TaNRT2.3(accession number AY053452), was isolatedfrom NO3--induced r...This paper reports the cloning and expression analysis of a high-affinity nitrate transporter inwheat ( Triticurn aestivurn L.). A full-length cDNA, TaNRT2.3(accession number AY053452), was isolatedfrom NO3--induced roots of wheat. The cDNA encodes a polypeptide with 507 amino acids and 12transmembrane domains, belongs to nitrate/nitrite porter (NNP) family within the major facilitator superfamily(MFS), and is closely related to other NRT2 proteins from plants. The expressions of TaNtTT2 genes inwheat tissues were analyzed using Northern blot, results indicated that TaNRT2 were induced specificallyin roots but not in shoots in response to both low (5-200 μmol/L) and high (2.0 retool/L) concentrationsof NO^-. TaNRT2transcripts were undetectable in N-deprived or NH4^+grown plant roots. The significantcorrelation between the time course of TaNtTT2transcription accumulation in the roots of wheat plantsgrown in 0.2 mmol/L NO3- and the time course of the nitrate uptake rates by wheat plants grown under thesame conditions suggested that TaNtTT2 played an important role in high-affinity NO3-uptake. Using thesplit root system, we found that supplying NO3- to one part of the roots induced the expression of TaNtTT2in the other part not supplied with NO3- or supplied with NH4^+, which implied that N cycling within plantsacted as a regulatory signal for N uptake.展开更多
A stable transformation system for the expression of foreign genes in the unicellular greenmarine alga (Dunaliella salina Teod.) was established. Using electroporation, the alga was transformed witha plasmid containin...A stable transformation system for the expression of foreign genes in the unicellular greenmarine alga (Dunaliella salina Teod.) was established. Using electroporation, the alga was transformed witha plasmid containing the hepatitis B surface antigen (HBsAg） gene and the chloramphenicol acetyltransferase(CAT) gene as a selectable gene. PCR and Southern blotting analysis indicated that the HBsAEgene wasintegrated into the D. salina genome. Northern dotting analysis showed that the HBsAg gene was expressedat the mRNA level. The stable expression of HBsAg protein in transformants was confirmed by HBsAgenzyme-linked immunosorbent assay (HBsAg EUSA) and Western blotting analysis. Also, PCR and Southernblotting analyses showed that the CA Tgene was integrated into the D, salina genome, and CAT EUSAindicated that CAT protein was stably expressed in the cells. The introduced HBsAg DNA and HBsAgprotein expression were stably maintained for at least 60 generations in media devoid of chloramphenicol.This is the first report of the stable expression of foreign genes in D. salina.展开更多
Two yield-enhancing genes (yld1.1 and yld2.1) are located on chromosomes 1 and 2 respectivelyin a weedy relative of cultivated rice, Oryza rufipogon. SSR markers RM9 and RM166 are closelylinked with the two loci respe...Two yield-enhancing genes (yld1.1 and yld2.1) are located on chromosomes 1 and 2 respectivelyin a weedy relative of cultivated rice, Oryza rufipogon. SSR markers RM9 and RM166 are closelylinked with the two loci respectively. Minghui63 (MH63) has been a widely used restorationline in hybrid rice production in China during the past two decades. The F1 of cross 'MH63O.rufipogon' was backcrossed with MH63 generation by generation. RM9 and RM166 were used toselect the plants from the progeny of the backcross populations. The results were as follows:(1) In BC2F1 population, the percentage of the individuals which have RM9 and RM166 amplifiedbands simultaneously was 12.2%, while in the BC3F1 population, that was 16.3%. (2) Among 400individuals of BC3F1, four yield-promising plants were obtained, with yield being 30% more thanthat of MH63. (3) The products amplified by primer RM166 in O. rufipogon and MH63 weresequenced. It was found that the DNA fragment sequence amplified by RM166 from MH63 was 101 bpshorter than that from O. rufipogon. The 101bp sequence is a part of an intron of the PCNA(proliferating cell nuclear antigen) gene.展开更多
It is reported that chromosome 1 R of rye (Secale cereale L) convey phosphorus use efficientgene (s), and 1RS/1BL translocation genotype Lovrin No. 10 is P use efficient. So we hypothesized whetherP efficient gene(s) ...It is reported that chromosome 1 R of rye (Secale cereale L) convey phosphorus use efficientgene (s), and 1RS/1BL translocation genotype Lovrin No. 10 is P use efficient. So we hypothesized whetherP efficient gene(s) locate on 1RS, and the high P efficiency of Lovrin No.10 is from 1RS? To test thishypothesis, we investigated the P use efficiency (PUE) of a doubled haploid (DH) population with 61 linesderived from anther culture of F1 hybrid between Lovrin No.10 and phosphorus uptake inefficient genotypeChinese Spring to see whether PUE differs between DH line with and without 1RS/1BL translocation.Acidic polyacrylamide-gel electrophoresis (A-PAGE) of gliadin and genomic DNA in situ hybridization (GISH)were employed to discriminate 1RS/1BL translocation DH lines from the normal 1B DH lines. Among the61 DH lines investigated, A-PAGE analysis showed that 34 lines contained the 1RS/1BL translocationchromosome, which was characterized by the presence of a 1RS-specific Sec- 1 marker bands. Furtherverification with GISH proved that 33 in the 34 lines contained a pair of homozygous 1RS/1BL transloca-tion chromosomes, only one line was a 1RS/1BL monosomic line. A field experiment was carried out on Pdeficient soil to investigate grain yield, biomass, numbers of spikes per plant (SPP), P uptake efficiency(PUpE), and P utilization efficiency (PUtE) of the DH lines and their parents under -P (nil P applied) and +P(60 kg P/hm2 applied) at maturity. Results showed soil P deficiency decreased the values of the first fourtraits in Lovrin No.10, but were more severe for Chinese Spring. Lovrin No.10 had higher values of all theabove tested traits at both -P and +P than Chinese Spring did, but had similar PUtE with Chinese Spring.These five traits segregated, and differed greatly among DH lines under both -P and +P conditions.Although the variations among DH lines exceeded the difference between the two parents, the averagevalues of the DH lines were between the two parents. The average of the above five traits, and P deficiencytolerance (PDT) (measured by relative grain yield of -P/+P) were not different between the DH lines withand without 1RS/1BL translocation. This indicated that there was no association between 1RS and PUEand PDT in Lovrin No.10, and 1RS may not have P efficient gene(s). Therefore, in the offspring of LovrinNo.10, it is possible to combine high PUE and PDT with good quality without the negative effect of 1RS onflour quality.展开更多
Signal transduction in early embryogenesis needs to be properly controlled. A new player involved in tuning down TGF β signaling has now been identified – new evidence that multi-layer control of signaling is essent...Signal transduction in early embryogenesis needs to be properly controlled. A new player involved in tuning down TGF β signaling has now been identified – new evidence that multi-layer control of signaling is essential in vivo.展开更多
A cross between wilt resistant flax variety Jinya7 and susceptible variety Jinya1 wasmade for mapping wilt resistance gene(s). The inoculation test of F1 and F2 progeny provedthat the resistance of Jinya7 to wilt is c...A cross between wilt resistant flax variety Jinya7 and susceptible variety Jinya1 wasmade for mapping wilt resistance gene(s). The inoculation test of F1 and F2 progeny provedthat the resistance of Jinya7 to wilt is controlled by two dominant genes. With 48 EcoRⅠ/MseⅠ primer combinations, amplified fragment length polymorphisms (AFLP) analysis wasperformed on two parents and their F2 resistance and susceptibility bulks. A total ofabout 3300 distinguishable bands were amplified, of which three bands had stabledifferences. The genetic linkage analysis of the three polymorphic DNA fragments withthe resistance gene(s) was made in the F2 segregating population derived from the crossbetween Jinya7 and Jinya1. The DNA fragment AG/CAG was found closely linked to one of thewilt-resistant genes, which with a genetic distance of 5.2cm, was tentatively named FuJ7(t).The cloned fragment AG/CAG was sequenced and then converted successfully to a sequencecharacterized amplified region (SCAR) marker, which can be used more conveniently in theidentification and marker-assisted selection for the wilt resistance gene FuJ7(t) toflax wilt.展开更多
Abstract: A rice mutant with reduced heading date (designated rhd1) found in a transgenic line of cultivar Teqing 2 (Oryza sativa L. ssp. indica) was used to identify the genes related to rice heading and thereby to s...Abstract: A rice mutant with reduced heading date (designated rhd1) found in a transgenic line of cultivar Teqing 2 (Oryza sativa L. ssp. indica) was used to identify the genes related to rice heading and thereby to study its molecular mechanism. Genetic analysis showed that rhd1 was a dominant mutation and did not result from T-DNA insertion. By using the differential display polymerase chain reaction (DD-PCR) technique, differential gene expression between rhd1 and Teqing 2 was compared and a rhd1-down-regulated c DNA fragment was identified. Sequence analysis showed that this fragment shared 99% similarity to the OsGRF1 (O. sativa growth-regulating factor 1) gene. The OsGRF1 gene encodes a putative transcription factor, which contains two conserved regions: the QLQ (Gln, Leu, Gln) and WRC (Trp, Arg, Cys) domains. Southern analysis indicates that OsGRF1 may be encoded by single copy gene in the rice genome. RNA interference results revealed that transgenic lines with reduced OsGRF1 transcript displayed delayed growth and development, developed small leaves, and had delayed heading. The extent of the phenotypes developed was well-correlated with the OsGRF1 gene transcript. Our results clearly demonstrate that the OsGRF1 gene is not only involved in regulating growth at the juvenile stage, but that it may also be involved in the regulation of heading in rice.展开更多
Most dehydration-responsive element-binding (DREB) factors interact specifically with the dehydration-responsive element (DRE) and control the expression of many stress-inducible genes in Arabidopsis. In rice (Oryza s...Most dehydration-responsive element-binding (DREB) factors interact specifically with the dehydration-responsive element (DRE) and control the expression of many stress-inducible genes in Arabidopsis. In rice (Oryza sativa L. cv. Lansheng), we cloned three DREB homologs: OsDREB1-1, OsDREB4- 1, and OsDREB4-2. The deduced amino acid sequences revealed that each protein contained a potential nuclear localization signal, an AP2 DNA-binding domain, and a possible acidic activation domain. The yeast one-hybrid assay indicated that both OsDREB4-1 and OsDREB4-2 proteins specifically bound to DRE and activated expression of the dual reporter genes of histidine (HIS3) and galactosidase (LacZ). In rice seedlings,expression of OsDREB4-1 was induced by dehydration and high salt, whereas OsDREB1-1 and OsDREB4-2 were expressed constitutively. Under normal growth conditions, OsDREB1-1 was expressed strongly in the leaf, sheath, and spike, was expressed relatively weak in the stem and only faintly expressed in the roots,whereas expression of transcripts of OsDREB4-1 and OsDREB4-2 was higher in the roots, stem, and spike,lower in the leaf, and undetectable in the sheath. Together, these results imply that expression of the OsDREB genes could be controlled by specific aspects of differentiation or development. Thus, OsDREB4-1 could function as a trans-acting factor in the DRE/DREB regulated stress-responsive pathway.展开更多
: The plant phytohormone cytokinin plays an important role in many facets of plant growth and development by regulating cell division and differentiation. Recent studies have shed significant light into the mechanisms...: The plant phytohormone cytokinin plays an important role in many facets of plant growth and development by regulating cell division and differentiation. Recent studies have shed significant light into the mechanisms of cytokinin metabolism and signaling. However, little is known about how the hormone is transported in planta, although it has been proposed that the hormone is presumably transported in nucleoside-conjugated forms. Here, we report the identification and characterization of cytokinin transporters in Arabidopsis. We previously reported that a gain-of-function mutation in the PGA22/AtIPT8 gene caused overproduction of cytokinins in planta. In an effort to screen for suppressor of pga 22/atipt 8 (soi) mutants, we identified a mutant soi33-1. Molecular and genetic analyses indicated that SOI33 encodes a putative equilibrative nucleoside transporter (ENT), previously designated as AtENT8. Members of this small gene family are presumed to be involved in the transport of nucleosides in eukaryotic cells. Under conditions of nitrogen starvation, loss-of-function mutations in SOI33/AtENT8 or in a related gene AtENT3 cause a reduced sensitivity to the nucleoside-type cytokinins isopentenyladenine riboside (iPR) and transzeatin riboside (tZR), but display a normal response to the free base-type cytokinins isopentenyladenine (iP) and trans-zeatin (tZ). Conversely, overexpression of SOI33/AtENT8 renders transgenic plants hypersensitive to iPR but not to iP. An in planta measurement experiment indicated that uptake efficiency of 3H-labeled iPR was reduced more than 40% in soi33 and atent3 mutants. However, a mutation in AtENT1 had no substantial effect on the cytokinin response and iPR uptake efficiency. Our results suggest that SOI33/ AtENT8 and AtENT3 are involved in the transport of nucleoside-type cytokinins in Arabidopsis.展开更多
Two G. somalense monosomic alien addition lines were identified from the derived backcross progenies of allohexaploid between G. hirsutum and G. somalense through cytological and morphological observation. Furthermore...Two G. somalense monosomic alien addition lines were identified from the derived backcross progenies of allohexaploid between G. hirsutum and G. somalense through cytological and morphological observation. Furthermore, the alien addition chromosome was identified and distinguished by RAPD analysis. A total of 160 RAPD primers were used for PCR amplification. Primer SBSG11 could produce a spe-cific molecular marker (600 bp) for monosomic alien addi-tion line Ⅰ(MAAL Ⅰ). Primer SBSC03 could produce a specific molecular marker (700 bp) for monosomic alien ad-dition line Ⅱ(MAAL Ⅱ). SBSE07 and SBSE08 could re-spectively produce common molecular marker for mono-somic alien addition lines Ⅰ and Ⅱ. G . somalense alien addition lines could be important for cotton improvement.展开更多
Soil-borne fungal and oomycetal pathogens cause devastating agricultural losses every year. The abundance and diversity of filamentous eukaryotes in the roots of healthy plants are in flue need by root-associated bact...Soil-borne fungal and oomycetal pathogens cause devastating agricultural losses every year. The abundance and diversity of filamentous eukaryotes in the roots of healthy plants are in flue need by root-associated bacteria that protect host plants from disease caused by fungi and oomycetes (Duran et al., 2018).展开更多
A spontaneous white panicle mutant was found from the F6 progenies of an indica/japonica cross. The mu-tant exhibits white stripes on its basal leaves while the pani-cles, rachis and pedicel are milky white colored at...A spontaneous white panicle mutant was found from the F6 progenies of an indica/japonica cross. The mu-tant exhibits white stripes on its basal leaves while the pani-cles, rachis and pedicel are milky white colored at flowering stage. Genetic analysis in an F2 population from the cross of Zhi7/white panicle mutant indicates that the white panicle phenotype is controlled by a single recessive nuclear gene, tentatively termed as wp(t). Using microsatellite markers, the wp(t) gene was anchored between the markers of SSR101 and SSR63.9 with a map distance of 2.3 and 0.8 cM, respec-tively, and co-segregated with the marker of SSR17 on rice chromosome 1.展开更多
In order to improve the carbon-assimilation ability of C3 plants, we isolated a C4-specific photosynthetic enzyme gene, Ppc (encode phosphoenolpyruvate carboxylase, PEPCase) from the genome of the C4 plant, sorghum, a...In order to improve the carbon-assimilation ability of C3 plants, we isolated a C4-specific photosynthetic enzyme gene, Ppc (encode phosphoenolpyruvate carboxylase, PEPCase) from the genome of the C4 plant, sorghum, and transformed rice with it. As shown by sequence analysis, the gene is composed of 10 exons and 9 introns, and the full-length transcript is 5989 bp long. A recombinant expres-sion vector, p1301PEPC, was constructed by inserting the gene into a plasmid vector, pCAMBIA1301, which was then transformed into two japonica rice varieties, Nongken 58 and Zhonghua 10, using an Agrobacterium-mediated transforma-tion system. PCR analysis, activity measurement of PEPCase, and protein-, RNA- and DNA-based hybridization all con-firmed the successful integration of the C4-specific Ppc gene into the nuclear genome of rice and its high level expression. Physiological studies revealed the photosynthetic features characterizing C4 plants such as marked lowering of CO2 compensation point and photorespiration rate, and im-proved carboxylation efficiency. This study provides useful experimental materials and opens up new avenues for fur-ther studies on improving photosynthetic efficiency of elite varieties of rice.展开更多
149 complete mitochondrial DNA (mtDNA) cytochrome b (Cyt b) genes (1140 bp) of Gymnocypris przewalskii, Gymnocypris eckloni and Gymnocypris scolisto-mus from the Lake Qinghai, Yellow River and Qaidam Basin were sequen...149 complete mitochondrial DNA (mtDNA) cytochrome b (Cyt b) genes (1140 bp) of Gymnocypris przewalskii, Gymnocypris eckloni and Gymnocypris scolisto-mus from the Lake Qinghai, Yellow River and Qaidam Basin were sequenced and analyzed. Consistent dendrogram indi-cated that the samples collected from the same species do not constitute a separate monophyletic group and all the samples were grouped into three highly divergent lineages (A, B and C). Among them, Lineage A contained all samples of G. przewalskii from the Lake Qinghai and partial samples of the G. eckloni from the Yellow River. Lineage B contained the remaining samples of G. eckloni from the Yellow River. Lineage C was composed of a monophyletic group by G. eck-loni from the Qaidam Basin. Analysis of molecular variance (AMOVA) indicated that most of genetic variations were detected within these three mtDNA lineages (93.12%), sug-gesting that there are three different lineages of Gymnocypris in this region. Our Cyt b sequence data showed that G. przewalskii was not a polytypic species, and G. scolistomus was neither an independent species nor a subspecies of G. eckloni. The divergent mtDNA lineages of G. eckloni from the Yellow River suggested that gene flow between the different populations was restricted to a certain extent by several gorges on the upper reach of the Yellow River. Lineage B of G. eckloni might be the genetic effect from the ancestor which was incorporated with the endemic schizothoracine fishes when the headward erosion of the Yellow River reached to its current headwaters of late. The G. eckloni from Basin Qaidam was a monophyletic group (lineage C) and Fst values within G. eckloni from the Yellow River were higher than 0.98, suggesting that the gene flow has been interrupted for a long time and the G. eckloni from Basin Qaidam might have been evolved into different species by ecology segrega-tion. The correlation between the rakers number of Gymno-cypris and population genetic variation was not significant. All Gymnocypris populations exhibited a low nucleotide di-versity (π = 0.00096―0.00485). Therefore the Gymnocypris populations from Basin Qaidam could have experienced se-vere bottleneck effect in history. Our result suggested Gym-nocypris populations of Basin Qaidam should give a high priority in conservation programs.展开更多
Resistance to rice blast pathogen mostly shows a quantitative trait controlled by several minor genes. Its complexity and the mutable characteristic of rice blast iso-lates both hinder the development of the blast res...Resistance to rice blast pathogen mostly shows a quantitative trait controlled by several minor genes. Its complexity and the mutable characteristic of rice blast iso-lates both hinder the development of the blast resistance re-search. The article here tried to explore the resistance gene distribution on rice chromosomes and the way of function. Totally 124 QTLs have been identified against 20 isolates using Cartographer software with a ZYQ8/JX17 DH popula-tion, which separately are at 100 loci of 72 marker intervals on 12 rice chromosomes. Of them, 16 QTLs were determined by the isolate HB-97-36-1. 82 QTLs (66.13%) are from the resistant parent alleles, ZYQ8, while 42 QTLs (33.87%) are from the susceptible parent alleles, JX17. In comparison of their positions on chromosome, most QTLs are clustered together and distributed nearby the major genes especially the regions on chromosomes 1, 2, 8, 10 and 12. Each QTL could account for the resistance variation between 3.52%—68.64%. And, a positional QTL might display the resistance to several different isolates with different contributions.展开更多
Fine mapping of Helminthosporium turcicum resistance gene Ht2 is extremely valuable for map-based cloning of the Ht2 gene, gaining a better knowledge of the distribution of resistance genes in maize genome and marker-...Fine mapping of Helminthosporium turcicum resistance gene Ht2 is extremely valuable for map-based cloning of the Ht2 gene, gaining a better knowledge of the distribution of resistance genes in maize genome and marker-assisted selection in maize breeding. An F2 mapping population was developed from a cross between a resistant inbred line 77Ht2 and a susceptible inbred line Huobai. With the aid of RFLP marker analyses, the Ht2 gene was mapped between the RFLP markers UMC89 and BNL2.369 on chromosome 8, with a genetic distance of 0.9 cM to BNL2.369. There was a linkage between SSR markers UMC1202, BNLG1152, UMC1149 and the Ht2 gene by SSR assay. Among the SSR markers, the genetic distance between UMC1149 and the Ht2 gene was 7.2 cM. By bulked segregant analysis 7 RAPD-amplified products which were probably linked to the Ht2 gene were selected after screening 450 RAPD primers and converted the single-copy ones into SCAR markers. Linkage analysis showed that the genetic distance between the SCAR marker SD-06633 and the Ht2 gene was 0.4 cM. From these results, a part of linkage map around the Ht2 gene was constructed.展开更多
A rice initiation-type lesion mimic mutant (imi) was identified, which was isolated from an indica rice Zhongxian 3037 through γ radiation mutagenesis. Trypan blue staining and sterile culture revealed that the mutan...A rice initiation-type lesion mimic mutant (imi) was identified, which was isolated from an indica rice Zhongxian 3037 through γ radiation mutagenesis. Trypan blue staining and sterile culture revealed that the mutant spontaneously developed lesions on the leaves in a develop mentally regulated and light-dependent manner. Genetic analysis indicated that the lesion mimic trait was controlled by a single resessive locus. Using public molecular markers and an F2 population derived from lmi and 93-11, we mapped the lmi locus to the short arm of chromosome 8, nearby the centromere, between two SSR markers RM547 and RM331. The genetic distance was 1.2 and 3.2 Cm, respectively. Then according to the public rice genomic sequence between the two SSR markers, lmi was further finely tagged by three CAPS markers: C4135-8, C4135-9 and C4135-10. And lmi locus was a co-segregated with marker C4135-10, providing a starting point for imi gene cloning.展开更多
基金supported by grants from the National Natural Science Foundation of China(No.39889003,30070074,30221002)a National Distinguished Young Scholar Award to Jia Yang LI.
文摘RAV1 is a novel DNA-binding protein with two distinct DNA-binding domains unique in higher plants,but its role in plant growth and development remains unknown. Using cDNA array,we found that transcription of RAV1 is downregulated by epibrassinolide (epiBL) in Arabidopsis suspension cells. RNA gel blot analysis revealed that epiBL-regulated RAV1 transcription involves neither protein phosphorylation/dephosphorylation nor newly synthesized protein,and does not require the functional BRI1,suggesting that this regulation might be through a new BR signaling pathway.Overexpressing RAV1 in Arabidopsis results in a retardation of lateral root and rosette leaf development,and the underexpression causes an earlier flowering phenotype,implying that RAV1 may function as a negative regulatory component of growth and development.
文摘AIM:To examine the role of nucleostemin in the growth regulation of gastric cancer,liver cancer and other cancers.METHODS:RT-PCR was used to clone the fragment of nucleostemin cDNA from HEK 293 cells.Eighteen kinds of malignant tumor tissues including gastric adenocarcinoma and liver cancer tissues,3 kinds of benign tumor tissues,3 kinds of benign hyperplastic tissues and normal tissues were employed to examine nucleostemin gene expression by RT-PCR,Slot blot,Northern blot and in situ hybridization.RESULTS:We successfully cloned a 570 bp fragment of nucleostemin-cDNA from HEK-293 cells.All edtected malignant tumor tissues,benign tumor tissues,and benign hyperplastic tissues had hign levels of nucleostemin expression.Nucleostemin was also expressed in human placenta tissue at a high levle.In terminally differentiated normal human adult kidney and mammary gland tissues,no nucleostemin expression could be detected.CONCLUSION:Nucleostemin can help regulate the proliferation of both cancer cells and stem cells.It might play an important role in the growth regulation of gastric cancer,liver cancer and other cancers.
基金Project supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KZCX2-413-3)the National Key Basic Research Support Foundation (NKBRSF) of China (No. G1999011803) the Australian Centre for
文摘Ammonia (NH3) volatilization, denitrification loss, and nitrous oxide (N2O) emission were investigated from an irrigated wheat-maize rotation field on the North China Plain, and the magnitude of gaseous N loss from denitrification and NH3 volatilization was assessed. The micrometeorological gradient diffusion method in conjunction with a Bowen Ratio system was utilized to measure actual NH3 fluxes over a large area, while the acetylene inhibition technique (intact soil cores) was employed for measurement of denitrification losses and N2O emissions. Ammonia volatilization loss was 26.62% of the applied fertilizer nitrogen (N) under maize, while 0.90% and 15.55% were lost from the wheat field at sowing and topdressing, respectively. The differences in NH3 volatilization between different measurement events may be due to differences between the fertilization methods, and to differences in climatic conditions such as soil temperature.Denitrification losses in the fertilized plots were 0.67%-2.87% and 0.31%-0.49% of the applied fertilizer N under maize and wheat after subtracting those of the controls, respectively. Nitrous oxide emissions in the fertilized plots were approximately 0.08%-0.41% and 0.26%-0.34% of the applied fertilizer N over the maize and wheat seasons after subtracting those of the controls, correspondingly. The fertilizer N losses due to NH3 volatilization were markedly higher than those through denitrification and nitrous oxide emissions. These results indicated that NH3 volatilization was an important N transformation in the crop-soil system and was likely to be the major cause of low efficiencies with N fertilizer in the study area. Denitrification was not a very important pathway of N fertilizer loss, but did result in important evolution of the greenhouse gas N2O and the effect of N2O emitted from agricultural fields on environment should not be overlooked.
文摘This paper reports the cloning and expression analysis of a high-affinity nitrate transporter inwheat ( Triticurn aestivurn L.). A full-length cDNA, TaNRT2.3(accession number AY053452), was isolatedfrom NO3--induced roots of wheat. The cDNA encodes a polypeptide with 507 amino acids and 12transmembrane domains, belongs to nitrate/nitrite porter (NNP) family within the major facilitator superfamily(MFS), and is closely related to other NRT2 proteins from plants. The expressions of TaNtTT2 genes inwheat tissues were analyzed using Northern blot, results indicated that TaNRT2 were induced specificallyin roots but not in shoots in response to both low (5-200 μmol/L) and high (2.0 retool/L) concentrationsof NO^-. TaNRT2transcripts were undetectable in N-deprived or NH4^+grown plant roots. The significantcorrelation between the time course of TaNtTT2transcription accumulation in the roots of wheat plantsgrown in 0.2 mmol/L NO3- and the time course of the nitrate uptake rates by wheat plants grown under thesame conditions suggested that TaNtTT2 played an important role in high-affinity NO3-uptake. Using thesplit root system, we found that supplying NO3- to one part of the roots induced the expression of TaNtTT2in the other part not supplied with NO3- or supplied with NH4^+, which implied that N cycling within plantsacted as a regulatory signal for N uptake.
文摘A stable transformation system for the expression of foreign genes in the unicellular greenmarine alga (Dunaliella salina Teod.) was established. Using electroporation, the alga was transformed witha plasmid containing the hepatitis B surface antigen (HBsAg） gene and the chloramphenicol acetyltransferase(CAT) gene as a selectable gene. PCR and Southern blotting analysis indicated that the HBsAEgene wasintegrated into the D. salina genome. Northern dotting analysis showed that the HBsAg gene was expressedat the mRNA level. The stable expression of HBsAg protein in transformants was confirmed by HBsAgenzyme-linked immunosorbent assay (HBsAg EUSA) and Western blotting analysis. Also, PCR and Southernblotting analyses showed that the CA Tgene was integrated into the D, salina genome, and CAT EUSAindicated that CAT protein was stably expressed in the cells. The introduced HBsAg DNA and HBsAgprotein expression were stably maintained for at least 60 generations in media devoid of chloramphenicol.This is the first report of the stable expression of foreign genes in D. salina.
文摘Two yield-enhancing genes (yld1.1 and yld2.1) are located on chromosomes 1 and 2 respectivelyin a weedy relative of cultivated rice, Oryza rufipogon. SSR markers RM9 and RM166 are closelylinked with the two loci respectively. Minghui63 (MH63) has been a widely used restorationline in hybrid rice production in China during the past two decades. The F1 of cross 'MH63O.rufipogon' was backcrossed with MH63 generation by generation. RM9 and RM166 were used toselect the plants from the progeny of the backcross populations. The results were as follows:(1) In BC2F1 population, the percentage of the individuals which have RM9 and RM166 amplifiedbands simultaneously was 12.2%, while in the BC3F1 population, that was 16.3%. (2) Among 400individuals of BC3F1, four yield-promising plants were obtained, with yield being 30% more thanthat of MH63. (3) The products amplified by primer RM166 in O. rufipogon and MH63 weresequenced. It was found that the DNA fragment sequence amplified by RM166 from MH63 was 101 bpshorter than that from O. rufipogon. The 101bp sequence is a part of an intron of the PCNA(proliferating cell nuclear antigen) gene.
文摘It is reported that chromosome 1 R of rye (Secale cereale L) convey phosphorus use efficientgene (s), and 1RS/1BL translocation genotype Lovrin No. 10 is P use efficient. So we hypothesized whetherP efficient gene(s) locate on 1RS, and the high P efficiency of Lovrin No.10 is from 1RS? To test thishypothesis, we investigated the P use efficiency (PUE) of a doubled haploid (DH) population with 61 linesderived from anther culture of F1 hybrid between Lovrin No.10 and phosphorus uptake inefficient genotypeChinese Spring to see whether PUE differs between DH line with and without 1RS/1BL translocation.Acidic polyacrylamide-gel electrophoresis (A-PAGE) of gliadin and genomic DNA in situ hybridization (GISH)were employed to discriminate 1RS/1BL translocation DH lines from the normal 1B DH lines. Among the61 DH lines investigated, A-PAGE analysis showed that 34 lines contained the 1RS/1BL translocationchromosome, which was characterized by the presence of a 1RS-specific Sec- 1 marker bands. Furtherverification with GISH proved that 33 in the 34 lines contained a pair of homozygous 1RS/1BL transloca-tion chromosomes, only one line was a 1RS/1BL monosomic line. A field experiment was carried out on Pdeficient soil to investigate grain yield, biomass, numbers of spikes per plant (SPP), P uptake efficiency(PUpE), and P utilization efficiency (PUtE) of the DH lines and their parents under -P (nil P applied) and +P(60 kg P/hm2 applied) at maturity. Results showed soil P deficiency decreased the values of the first fourtraits in Lovrin No.10, but were more severe for Chinese Spring. Lovrin No.10 had higher values of all theabove tested traits at both -P and +P than Chinese Spring did, but had similar PUtE with Chinese Spring.These five traits segregated, and differed greatly among DH lines under both -P and +P conditions.Although the variations among DH lines exceeded the difference between the two parents, the averagevalues of the DH lines were between the two parents. The average of the above five traits, and P deficiencytolerance (PDT) (measured by relative grain yield of -P/+P) were not different between the DH lines withand without 1RS/1BL translocation. This indicated that there was no association between 1RS and PUEand PDT in Lovrin No.10, and 1RS may not have P efficient gene(s). Therefore, in the offspring of LovrinNo.10, it is possible to combine high PUE and PDT with good quality without the negative effect of 1RS onflour quality.
文摘Signal transduction in early embryogenesis needs to be properly controlled. A new player involved in tuning down TGF β signaling has now been identified – new evidence that multi-layer control of signaling is essential in vivo.
文摘A cross between wilt resistant flax variety Jinya7 and susceptible variety Jinya1 wasmade for mapping wilt resistance gene(s). The inoculation test of F1 and F2 progeny provedthat the resistance of Jinya7 to wilt is controlled by two dominant genes. With 48 EcoRⅠ/MseⅠ primer combinations, amplified fragment length polymorphisms (AFLP) analysis wasperformed on two parents and their F2 resistance and susceptibility bulks. A total ofabout 3300 distinguishable bands were amplified, of which three bands had stabledifferences. The genetic linkage analysis of the three polymorphic DNA fragments withthe resistance gene(s) was made in the F2 segregating population derived from the crossbetween Jinya7 and Jinya1. The DNA fragment AG/CAG was found closely linked to one of thewilt-resistant genes, which with a genetic distance of 5.2cm, was tentatively named FuJ7(t).The cloned fragment AG/CAG was sequenced and then converted successfully to a sequencecharacterized amplified region (SCAR) marker, which can be used more conveniently in theidentification and marker-assisted selection for the wilt resistance gene FuJ7(t) toflax wilt.
文摘Abstract: A rice mutant with reduced heading date (designated rhd1) found in a transgenic line of cultivar Teqing 2 (Oryza sativa L. ssp. indica) was used to identify the genes related to rice heading and thereby to study its molecular mechanism. Genetic analysis showed that rhd1 was a dominant mutation and did not result from T-DNA insertion. By using the differential display polymerase chain reaction (DD-PCR) technique, differential gene expression between rhd1 and Teqing 2 was compared and a rhd1-down-regulated c DNA fragment was identified. Sequence analysis showed that this fragment shared 99% similarity to the OsGRF1 (O. sativa growth-regulating factor 1) gene. The OsGRF1 gene encodes a putative transcription factor, which contains two conserved regions: the QLQ (Gln, Leu, Gln) and WRC (Trp, Arg, Cys) domains. Southern analysis indicates that OsGRF1 may be encoded by single copy gene in the rice genome. RNA interference results revealed that transgenic lines with reduced OsGRF1 transcript displayed delayed growth and development, developed small leaves, and had delayed heading. The extent of the phenotypes developed was well-correlated with the OsGRF1 gene transcript. Our results clearly demonstrate that the OsGRF1 gene is not only involved in regulating growth at the juvenile stage, but that it may also be involved in the regulation of heading in rice.
基金国家重点基础研究发展计划(973计划)，the National Special Program for Research and Industrialization of Transgenic Plants，国家科技攻关项目
文摘Most dehydration-responsive element-binding (DREB) factors interact specifically with the dehydration-responsive element (DRE) and control the expression of many stress-inducible genes in Arabidopsis. In rice (Oryza sativa L. cv. Lansheng), we cloned three DREB homologs: OsDREB1-1, OsDREB4- 1, and OsDREB4-2. The deduced amino acid sequences revealed that each protein contained a potential nuclear localization signal, an AP2 DNA-binding domain, and a possible acidic activation domain. The yeast one-hybrid assay indicated that both OsDREB4-1 and OsDREB4-2 proteins specifically bound to DRE and activated expression of the dual reporter genes of histidine (HIS3) and galactosidase (LacZ). In rice seedlings,expression of OsDREB4-1 was induced by dehydration and high salt, whereas OsDREB1-1 and OsDREB4-2 were expressed constitutively. Under normal growth conditions, OsDREB1-1 was expressed strongly in the leaf, sheath, and spike, was expressed relatively weak in the stem and only faintly expressed in the roots,whereas expression of transcripts of OsDREB4-1 and OsDREB4-2 was higher in the roots, stem, and spike,lower in the leaf, and undetectable in the sheath. Together, these results imply that expression of the OsDREB genes could be controlled by specific aspects of differentiation or development. Thus, OsDREB4-1 could function as a trans-acting factor in the DRE/DREB regulated stress-responsive pathway.
基金国家自然科学基金，中国科学院知识创新工程项目，科技部资助项目，the Ministry of Education, Culture, Sports, Science，Grants-in-Aids for Scientific Research on Functional Analysis of Genes Relevant to Agriculturally Important Traits in Rice Genome，中国科学院'百人计划'，国家自然科学基金
文摘: The plant phytohormone cytokinin plays an important role in many facets of plant growth and development by regulating cell division and differentiation. Recent studies have shed significant light into the mechanisms of cytokinin metabolism and signaling. However, little is known about how the hormone is transported in planta, although it has been proposed that the hormone is presumably transported in nucleoside-conjugated forms. Here, we report the identification and characterization of cytokinin transporters in Arabidopsis. We previously reported that a gain-of-function mutation in the PGA22/AtIPT8 gene caused overproduction of cytokinins in planta. In an effort to screen for suppressor of pga 22/atipt 8 (soi) mutants, we identified a mutant soi33-1. Molecular and genetic analyses indicated that SOI33 encodes a putative equilibrative nucleoside transporter (ENT), previously designated as AtENT8. Members of this small gene family are presumed to be involved in the transport of nucleosides in eukaryotic cells. Under conditions of nitrogen starvation, loss-of-function mutations in SOI33/AtENT8 or in a related gene AtENT3 cause a reduced sensitivity to the nucleoside-type cytokinins isopentenyladenine riboside (iPR) and transzeatin riboside (tZR), but display a normal response to the free base-type cytokinins isopentenyladenine (iP) and trans-zeatin (tZ). Conversely, overexpression of SOI33/AtENT8 renders transgenic plants hypersensitive to iPR but not to iP. An in planta measurement experiment indicated that uptake efficiency of 3H-labeled iPR was reduced more than 40% in soi33 and atent3 mutants. However, a mutation in AtENT1 had no substantial effect on the cytokinin response and iPR uptake efficiency. Our results suggest that SOI33/ AtENT8 and AtENT3 are involved in the transport of nucleoside-type cytokinins in Arabidopsis.
文摘Two G. somalense monosomic alien addition lines were identified from the derived backcross progenies of allohexaploid between G. hirsutum and G. somalense through cytological and morphological observation. Furthermore, the alien addition chromosome was identified and distinguished by RAPD analysis. A total of 160 RAPD primers were used for PCR amplification. Primer SBSG11 could produce a spe-cific molecular marker (600 bp) for monosomic alien addi-tion line Ⅰ(MAAL Ⅰ). Primer SBSC03 could produce a specific molecular marker (700 bp) for monosomic alien ad-dition line Ⅱ(MAAL Ⅱ). SBSE07 and SBSE08 could re-spectively produce common molecular marker for mono-somic alien addition lines Ⅰ and Ⅱ. G . somalense alien addition lines could be important for cotton improvement.
文摘Soil-borne fungal and oomycetal pathogens cause devastating agricultural losses every year. The abundance and diversity of filamentous eukaryotes in the roots of healthy plants are in flue need by root-associated bacteria that protect host plants from disease caused by fungi and oomycetes (Duran et al., 2018).
文摘A spontaneous white panicle mutant was found from the F6 progenies of an indica/japonica cross. The mu-tant exhibits white stripes on its basal leaves while the pani-cles, rachis and pedicel are milky white colored at flowering stage. Genetic analysis in an F2 population from the cross of Zhi7/white panicle mutant indicates that the white panicle phenotype is controlled by a single recessive nuclear gene, tentatively termed as wp(t). Using microsatellite markers, the wp(t) gene was anchored between the markers of SSR101 and SSR63.9 with a map distance of 2.3 and 0.8 cM, respec-tively, and co-segregated with the marker of SSR17 on rice chromosome 1.
文摘In order to improve the carbon-assimilation ability of C3 plants, we isolated a C4-specific photosynthetic enzyme gene, Ppc (encode phosphoenolpyruvate carboxylase, PEPCase) from the genome of the C4 plant, sorghum, and transformed rice with it. As shown by sequence analysis, the gene is composed of 10 exons and 9 introns, and the full-length transcript is 5989 bp long. A recombinant expres-sion vector, p1301PEPC, was constructed by inserting the gene into a plasmid vector, pCAMBIA1301, which was then transformed into two japonica rice varieties, Nongken 58 and Zhonghua 10, using an Agrobacterium-mediated transforma-tion system. PCR analysis, activity measurement of PEPCase, and protein-, RNA- and DNA-based hybridization all con-firmed the successful integration of the C4-specific Ppc gene into the nuclear genome of rice and its high level expression. Physiological studies revealed the photosynthetic features characterizing C4 plants such as marked lowering of CO2 compensation point and photorespiration rate, and im-proved carboxylation efficiency. This study provides useful experimental materials and opens up new avenues for fur-ther studies on improving photosynthetic efficiency of elite varieties of rice.
文摘149 complete mitochondrial DNA (mtDNA) cytochrome b (Cyt b) genes (1140 bp) of Gymnocypris przewalskii, Gymnocypris eckloni and Gymnocypris scolisto-mus from the Lake Qinghai, Yellow River and Qaidam Basin were sequenced and analyzed. Consistent dendrogram indi-cated that the samples collected from the same species do not constitute a separate monophyletic group and all the samples were grouped into three highly divergent lineages (A, B and C). Among them, Lineage A contained all samples of G. przewalskii from the Lake Qinghai and partial samples of the G. eckloni from the Yellow River. Lineage B contained the remaining samples of G. eckloni from the Yellow River. Lineage C was composed of a monophyletic group by G. eck-loni from the Qaidam Basin. Analysis of molecular variance (AMOVA) indicated that most of genetic variations were detected within these three mtDNA lineages (93.12%), sug-gesting that there are three different lineages of Gymnocypris in this region. Our Cyt b sequence data showed that G. przewalskii was not a polytypic species, and G. scolistomus was neither an independent species nor a subspecies of G. eckloni. The divergent mtDNA lineages of G. eckloni from the Yellow River suggested that gene flow between the different populations was restricted to a certain extent by several gorges on the upper reach of the Yellow River. Lineage B of G. eckloni might be the genetic effect from the ancestor which was incorporated with the endemic schizothoracine fishes when the headward erosion of the Yellow River reached to its current headwaters of late. The G. eckloni from Basin Qaidam was a monophyletic group (lineage C) and Fst values within G. eckloni from the Yellow River were higher than 0.98, suggesting that the gene flow has been interrupted for a long time and the G. eckloni from Basin Qaidam might have been evolved into different species by ecology segrega-tion. The correlation between the rakers number of Gymno-cypris and population genetic variation was not significant. All Gymnocypris populations exhibited a low nucleotide di-versity (π = 0.00096―0.00485). Therefore the Gymnocypris populations from Basin Qaidam could have experienced se-vere bottleneck effect in history. Our result suggested Gym-nocypris populations of Basin Qaidam should give a high priority in conservation programs.
文摘Resistance to rice blast pathogen mostly shows a quantitative trait controlled by several minor genes. Its complexity and the mutable characteristic of rice blast iso-lates both hinder the development of the blast resistance re-search. The article here tried to explore the resistance gene distribution on rice chromosomes and the way of function. Totally 124 QTLs have been identified against 20 isolates using Cartographer software with a ZYQ8/JX17 DH popula-tion, which separately are at 100 loci of 72 marker intervals on 12 rice chromosomes. Of them, 16 QTLs were determined by the isolate HB-97-36-1. 82 QTLs (66.13%) are from the resistant parent alleles, ZYQ8, while 42 QTLs (33.87%) are from the susceptible parent alleles, JX17. In comparison of their positions on chromosome, most QTLs are clustered together and distributed nearby the major genes especially the regions on chromosomes 1, 2, 8, 10 and 12. Each QTL could account for the resistance variation between 3.52%—68.64%. And, a positional QTL might display the resistance to several different isolates with different contributions.
基金This work was jointly supported by the National Transgenic Plant Research Foundation of China (Grant No. J00-A-002) and the National Research Foundation for Key Techniques (The Explo-ration and Application of Crop Resources,2001-2003,04-012) of China.
文摘Fine mapping of Helminthosporium turcicum resistance gene Ht2 is extremely valuable for map-based cloning of the Ht2 gene, gaining a better knowledge of the distribution of resistance genes in maize genome and marker-assisted selection in maize breeding. An F2 mapping population was developed from a cross between a resistant inbred line 77Ht2 and a susceptible inbred line Huobai. With the aid of RFLP marker analyses, the Ht2 gene was mapped between the RFLP markers UMC89 and BNL2.369 on chromosome 8, with a genetic distance of 0.9 cM to BNL2.369. There was a linkage between SSR markers UMC1202, BNLG1152, UMC1149 and the Ht2 gene by SSR assay. Among the SSR markers, the genetic distance between UMC1149 and the Ht2 gene was 7.2 cM. By bulked segregant analysis 7 RAPD-amplified products which were probably linked to the Ht2 gene were selected after screening 450 RAPD primers and converted the single-copy ones into SCAR markers. Linkage analysis showed that the genetic distance between the SCAR marker SD-06633 and the Ht2 gene was 0.4 cM. From these results, a part of linkage map around the Ht2 gene was constructed.
基金This work was supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KXCXZ-1-02-01)the National Natural Science Foundation of China(Grant No.39880020).
文摘A rice initiation-type lesion mimic mutant (imi) was identified, which was isolated from an indica rice Zhongxian 3037 through γ radiation mutagenesis. Trypan blue staining and sterile culture revealed that the mutant spontaneously developed lesions on the leaves in a develop mentally regulated and light-dependent manner. Genetic analysis indicated that the lesion mimic trait was controlled by a single resessive locus. Using public molecular markers and an F2 population derived from lmi and 93-11, we mapped the lmi locus to the short arm of chromosome 8, nearby the centromere, between two SSR markers RM547 and RM331. The genetic distance was 1.2 and 3.2 Cm, respectively. Then according to the public rice genomic sequence between the two SSR markers, lmi was further finely tagged by three CAPS markers: C4135-8, C4135-9 and C4135-10. And lmi locus was a co-segregated with marker C4135-10, providing a starting point for imi gene cloning.
