普通小麦基因组中耐低磷胁迫特性的染色体控制

以普通小麦中国春的一套缺四体为材料,对其耐低磷胁迫特性进行鉴定和遗传分析。结果表明：（１）第１,４,７部分同源群与低磷胁迫特性关系最密切,且第１,７部分同源群内各染色体间在该性状的遗传互补性良好。第４部分同源群则不同,４Ａ可以有效补偿４Ｂ与４Ｄ的缺失,反之则不能。（２）第２,３,５６部分同源群与低磷胁迫特性关系不密切,且这些同源群内某一染以体的缺失大多不能被其他染色体有效地补偿,尤其是第３与第６部     

The genetic basis of zinc tolerance in the metallophyte Arabidopsis halleri ssp. halleri (Brassicaceae): an analysis of quantitative trait loci

The species Arabidopsis halleri, an emerging model for the study of heavy metal tolerance and accumulation in plants, has evolved a high level of constitutive zinc tolerance. Mapping of quantitative trait loci (QTL) was used to investigate the genetic architecture of zinc tolerance in this species. A first-generation backcross progeny of A. halleri ssp. halleri from a highly contaminated industrial site and its nontolerant relative A. lyrata ssp. petraea was produced and used for QTL mapping of zinc tolerance. A genetic map covering most of the A. halleri genome was constructed using 85 markers. Among these markers, 65 were anchored in A. thaliana and revealed high synteny with other Arabidopsis genomes. Three QTL of comparable magnitude on three different linkage groups were identified. At all QTL positions zinc tolerance was enhanced by A. halleri alleles, indicating directional selection for higher zinc tolerance in this species. The two-LOD support intervals associated with these QTL cover 24, 4, and 13 cM. The importance of each of these three regions is emphasized by their colocalization with HMA4, MTP1-A, and MTP1-B, respectively, three genes well known to be involved in metal homeostasis and tolerance in plants.     

Identification and characterization of an expansin gene AsEXP1 associated with heat tolerance in C3 Agrostis grass species

Plant tolerance of heat stress involves various changes at physiological and molecular levels. The objective of this study was to examine the expression of a gene encoding expansin protein in relation to heat tolerance in two C(3) grass species and genotypes differing in heat tolerance. Heat-tolerant, thermal Agrostis scabra, adapted to high temperatures in geothermal areas in Yellowstone National Park, was subjected to 20 degrees C (control) or 40 degrees C (heat stress) for 7 d in a growth chamber. Differential display analysis identified that a gene, AsEXP1, encoding an expansin protein, was strongly up-regulated in leaves exposed to heat stress in thermal A. scabra. Virtual northern hybridization and RT-PCR confirmed that AsEXP1 was a heat-inducible gene in leaves. The expression of AsEXP1 was induced at 1 h of plant exposure to heat stress and reached the highest level of expression at 4 h of treatment. A 1.3 kb full-length cDNA of AsEXP1 was isolated, which encodes a 251 amino acid protein. Two ecotypes of thermal A. scabra and 10 genotypes of Agrostis stolonifera (creeping bentgrass), a widely used turfgrass species in cool climatic regions, varying in the level of heat tolerance, were exposed to 40 degrees C for 7 d to examine the level of AsEXP1 expression in relation to heat tolerance. Genetic variation in heat tolerance was evaluated by measuring cell membrane stability, photochemical efficiency, and leaf growth. RT-PCR analysis revealed that the level of AsEXP1 in different genotypes was positively correlated with the level of heat tolerance in both grass species. The results first identified a heat-related expansin gene in grass species and suggest that AsEXP1 may be useful as a molecular marker to select for heat-tolerant grass germplasm.     

Modulation of the induction and circumvention of immunological tolerance to human gamma-globulin by interleukin 1

As with agents capable of causing the release of IL 1, IL 1 itself is capable of modulating certain tolerance-inducing events. Under the condition used in the present study, it previously has been firmly established that injection of A/J mice with DHGG induces a state of antigen-specific tolerance in both T helper (Th) and B cells. The tolerance in the B cell is of long duration, whereas that in the B cell is of shorter duration. Recombinant IL 1 (rIL 1) given shortly after the tolerogen DHGG results in the inhibition of the induction of tolerance resulting in antibody production. The induction of tolerance is inhibited at both its antigen-specific Th cell and B cell levels, although the latter may be caused by the former. The inhibition of the induction of tolerance by rIL 1 is not correlated to the generation of antigen-specific T suppressor cells. IL 1 mimics lipopolysaccharide and 8-bromoguanosine, which generate IL 1 production, in its ability to interfere with the in vivo induction of tolerance. However, in contrast to these latter mitogens which cause both terminal differentiation of B cells and IL 1 production, IL 1 itself does not cause in vivo circumvention of long-term tolerant Th cells in the presence of competent B cells and antigen. These latter findings suggest that a signal(s) in addition to those delivered by IL 1 is required for activation of the B cell compartment recovering from tolerance to antibody production. AHGG (immunogen) is a potent generator of IL 1 release, whereas DHGG has no effect on IL 1 release from macrophages and AHGG inhibits the induction of tolerance by DHGG. These latter results suggest that the lack of an IL 1 signal may be responsible for the deliverance of a tolerogenic rather than an immunogenic signal to the Th cell.     

A method for the rapid development of opiate tolerance in the guinea pig ileum

The rate and degree of in vitro tolerance development to morphine, normorphine and d,1-methadone were assessed on the excised guinea pig ileum. Agonists in fixed concentrations at 1/4, 1/2, 1 and 2 x IC50 were incubated with the tissue for 1, 2 or 4 hours. The degree of tolerance development was expressed as a ratio of the IC50 after and before incubation. A high degree of tolerance developed to all three agonists and the effect could be prevented by co-incubation with naloxone. Tolerance development was stereo-specific; levorphanol and 1-methadone developed much higher degrees of tolerance than their respective d-isomers. Furthermore, under the same conditions, subsensitivity to acetylcholine, norepinephrine, and adenosine monophosphate did not develop. The in vitro tolerance was accompanied by physical dependence development as evidenced by the fact that naloxone elicited muscular contracture in the tolerant ileum. cAMP enhanced the development of tolerance to normorphine and cycloheximide could reduce this phenomenon. It is concluded that the procedure may facilitate studies on the mechanisms involved in the development of opiate tolerance and physical dependence.     

Alterations in the antigenic structure of two major HSV-1 glycoproteins, gC and gB, influence immune regulation and susceptibility to murine herpes keratitis

We previously demonstrated that anterior chamber (AC) injection of HSV-1 before or simultaneous with topical corneal HSV-1 infection resulted in cellular immune tolerance of HSV-1 Ag and a reduced frequency of corneal stromal lesions. In the present study, we have investigated the role of the HSV-1 cell-surface glycoproteins gC and gB in the induction of tolerance, and the resulting reduced susceptibility to HSV-1 corneal stromal disease. These studies utilized mutant strains of HSV-1 with deletion or point mutations in the gene coding for gC or gB. Groups of mice received topical corneal infections with wild-type HSV-1, followed by AC injection of the same eye with wild-type HSV-1 or a mutant strain. Varying the antigenic composition of the virus injected into the AC resulted in three distinct patterns of immune responsiveness. In agreement with our previous findings, AC injection of wild-type HSV-1 induced a state of HSV-1 specific tolerance that extended to both the delayed type hypersensitivity (DTH) and CTL responses. A mutant strain lacking gC (gC-) induced partial tolerance characterized by undetectable CTL activity but a normal DTH response. A mutant strain lacking gB (gB-) caused partial suppression of the CTL response and no reduction of the DTH response. Thus, whereas gB may be involved in CTL tolerance induction in this model, gC clearly is not involved. In contrast, both gC and gB must be present in the AC to induce detectable DTH tolerance. The latter interpretation was strengthened by the observation that AC injection of a mixture of gC- (expressing normal gB) and gB- (expressing normal gC) effectively suppressed the DTH response to wild-type HSV-1. A panel of mar mutants with individual point mutations affecting gC and gB was used to identify the epitopes responsible for induction of DTH tolerance. Two of the gC mutants failed to induce DTH tolerance to wild-type HSV-1 when injected into the AC, suggesting that the sites on the gC molecule that are altered by these mutations are important for the induction of DTH tolerance. Similarly, one of the mar mutants for gB uniformly failed to suppress the DTH response, while another had a variable effect. The unique pattern of cellular immune reactivity exhibited by the mice receiving simultaneous topical corneal infection with wild-type HSV-1 and AC injection of gC- (no CTL but normal DTH) was associated with significantly reduced susceptibility to HSV-1 corneal stromal lesions.(ABSTRACT TRUNCATED AT 400 WORDS)     

Use of a stress inducible promoter to drive ectopic AtCBF expression improves potato freezing tolerance while minimizing negative effects on tuber yield

Solanum tuberosum is a frost-sensitive species incapable of cold acclimation. A brief exposure to frost can significantly reduce its yields, while hard frosts can completely destroy entire crops. Thus, gains in freezing tolerance of even a few degrees would be of considerable benefit relative to frost damage. The S . tuberosum cv. Umatilla was transformed with three Arabidopsis CBF genes ( AtCBF1-3 ) driven by either a constitutive CaMV35S or a stress-inducible Arabidopsis rd29A promoter. AtCBF1 and AtCBF3 over-expression via the 35S promoter increased freezing tolerance about 2 °C, whereas AtCBF2 over-expression failed to increase freezing tolerance. Transgenic plants of AtCBF1 and AtCBF3 driven by the rd29A promoter reached the same level of freezing tolerance as the 35S versions within a few hours of exposure to low but non-freezing temperatures. Constitutive expression of AtCBF genes was associated with negative phenotypes, including smaller leaves, stunted plants, delayed flowering, and reduction or lack of tuber production. While imparting the same degree of freezing tolerance, control of AtCBF expression via the stress-inducible promoter ameliorated these negative phenotypic effects and restored tuber production to levels similar to wild-type plants. These results suggest that use of a stress-inducible promoter to direct CBF transgene expression can yield significant gains in freezing tolerance without negatively impacting agronomically important traits in potato.     

Development of an immuno-affinity column for ochratoxin analysis using an organic solvent-tolerant monoclonal antibody

Two kinds of monoclonal antibodies (MoAbs), OCA-10A and OCA-1B, were prepared based on their specificity to ochratoxin A (OTA) and ochratoxin B (OTB) and on their tolerance to 40% methanol. In an indirect competitive enzyme-linked immunosorbent assay, the half maximal inhibitory concentration (IC(50)) value of OCA-10A was 27ng/mL for OTA and 17ng/mL for OTB, and that of OCA-1B was 28ng/mL for OTA and 13ng/mL for OTB. Immuno-affinity columns (IACs) using these MoAbs were prepared with agarose gel beads. The IAC with OCA-1B showed a NaCl-dependent binding ability to OTA and OTB, while interestingly, the IAC with OCA-10A bound to them without NaCl. The IAC with OCA-10A showed a high methanol tolerance when compared with existing IACs, as expected from the high methanol tolerance of OCA-10A itself. Such tolerance was maintained for the application of the cocoa extract with 70% methanol and the wheat extract with 60% acetonitrile, while the tolerance was slightly altered by interference from the cocoa extract. Examinations with organic solvents at higher concentrations than the allowable level in existing IACs showed that OTA and OTB spiked with wheat, cocoa and red wine could be purified with high recovery. The newly developed IAC is expected to show sufficient clean-up ability for food analyses.     

Isolation and characterization of a metronidazole tolerant mutant of the cyanobacterium Spirulina platensis exhibiting multiple stress tolerance

Mutant cells of Spirulina platensis isolated after chemical mutagenesis (NTG treatment) exhibited approximately three-fold higher tolerance to metronidazole and DCMU (3,4-dichlorophenyl-1, 1-dimethylurea) as compared with wild-type cells. At the same time, mutant cells exhibited a several-fold higher tolerance to supra-high irradiance (38 W/m2) than the wild-type, a further response involving Hill reaction activity in the mutant towards the supra-high irradiance mechanism which enabled the mutant cells to withstand the high light intensities. The metronidazole and DCMU tolerance in the mutant cells could not be obviously attributed to lower rates of growth and photosynthesis as suggested previously. A typical coiling pattern in the mutant cells might result in a reduction of exposed surface area, thereby restricting entry of the above toxins. The mutant strains exhibiting tolerance to multiple stresses are potentially useful for application under field conditions.     

棉花萌发期和苗期耐盐性评价及耐盐指标筛选

于2010年在江苏南京农业大学人工气候室内进行砂培试验,采用不同浓度的NaCl水溶液模拟盐胁迫,以多项指标盐害系数隶属函数值和总隶属函数值为依据,比较了13个棉花品种萌发期和苗期的耐盐性,并进行聚类分析.结果表明:150mmol·L-1NaCl是进行棉花耐盐性鉴定的适宜盐浓度.棉花的耐盐性在生育期和品种间表现不同:中棉所44和中棉所177是在萌发期和苗期均表现稳定的耐盐品种,表现稳定但不耐盐品种有中棉所102、苏棉12号和泗棉3号,表现稳定且中等耐盐品种有中棉所103、德夏棉1号和美棉33B;发芽率、发芽势、发芽指数、活力指数和鲜质量的盐害系数可以作为棉花萌发期耐盐鉴定指标,株高、叶片伸展速率、地上部干质量、根系干质量、根系活力和净光合速率的盐害系数可以作为棉花苗期耐盐鉴定指标.     

Proceedings: Correlation of various clinical parameters with glucose tolerance test in women using oral contraceptives

A study was carried out to determine whether oral contraceptives affect carbohydrate metabolism as assessed by glucose tolerance curves. Glucose tolerance tests were carried out in seventy-six women. The women were divided into two groups. The first group constituted the control and the second group comprised women taking combination oral contraceptives. The glucose tolerance curves were correlated with: (1) the duration of thereapy; (2) the family history of diabetes; (3) the obstetric history; (4) age: (5) weight gain; (6) parity; and (7) changes in blood pressure. The combination type of oral contraceptives were observed to affect adversely the glucose tolerance test. A significant correlation was recorded between the familial diabetic history, intake of combination contraceptives and abnormal glucose tolerance tests. A history of birth of a large baby was found to be an important indicator of abnormal values of glucose tolerance in women taking a combination type of oral contraceptive. Such women showed an abnormal curve pattern at a much earlier age in life compared with controls. It was also observed that a high percentage of women who had gained excessive weight on combination contraceptives had an altered glucose tolerance test. Parity and blood pressure were two parameters which did not reveal any correlation with abnormal glucose tolerance curves.     

Mapping of loci affecting copper tolerance in wheat—The possible impact of the vernalization gene Vrn-A1

Pot experiments with copper-treated soil and a control were performed in a greenhouse to determine QTLs for copper tolerance in wheat, using deletion, introgression and single chromosome recombinant lines. Genetic and physical mapping identified loci for copper tolerance on the long arm of chromosomes 5A and 5D, while loci with minor effects were found on the long and short arms of chromosome 5B. Tests on ‘Chinese Spring’–Aegilops tauschii introgression lines revealed a locus influencing copper tolerance on chromosome 3DS. QTLs for copper tolerance on chromosome 5A were mapped genetically and physically to exactly the same position as the gene for vernalization requirement (Vrn-A1). It is therefore suggested that Vrn-A1 may have a pleiotropic effect on copper tolerance may be due to the control of Cbf genes.     

Inheritance of tolerance susceptibility to human gamma-globulin in congenic mice.

The genetic control of susceptibility to tolerance induction with human gamma-globulin (HGG) was studied by using H-2 congenic mice. Strains tested that were congenic with C57BL/10Sn were completely tolerized by 1.0 mg deaggregated HGG. In contrast A/Sn mice showed full tolerance whereas A.SW mice were only intermediately tolerant. It was further shown that (B10 X SJL)F1 mice could be rendered tolerant but (B10.S X SJL)F1 mice could not. These data indicate a role for H-2 linked genes in control of tolerance susceptibility. Results obtained with the progeny of (B10.S X SJL)F1 backcrossed to B10.S indicate that two non-H-2 linked genes are involved in control of tolerance induction. Preliminary mapping studies show the H-2 gene located to the left of the IC subregion. These results confirm our previous finding that both H-2 and non-H-2 genes control susceptibility of adult mice to tolerance induction with HGG.     

小麦耐低磷相关性状的全基因组关联分析

通过对小麦耐低磷相关性状进行全基因组关联分析(GWAS,genome-wide association study),挖掘与小麦耐低磷性显著相关的单核苷酸多态性标记(SNP,single nucleotide polymorphism)位点及候选基因,为小麦耐低磷性状的遗传基础和分子机制研究提供理论参考。本试验以198份黄淮麦区小麦品种(系)为试验材料,设置低磷和正常磷营养液水培试验,利用小麦35K芯片对分布于小麦全基因组的11896个SNP,采用Q+K关联模型对小麦耐低磷性相关性状进行关联分析。结果表明,小麦耐低磷性状表现出广泛的表型变异,变异系数为15.65%~26.59%,多态性信息含量(PIC,polymorphic information content)为0.095~0.500。群体结构分析表明,试验所用自然群体可分为2个亚群,GWAS共检测到67个与小麦耐低磷相关性状显著关联的SNP位点(P≤0.001),这些位点分布在除3A、3B和3D以外的18条染色体上,单个SNP位点可解释5.826%~9.552%的表型变异。在这些显著位点中有4个SNP位点同时关联到了2个不同的耐低磷性状。对67个SNP位点进行发掘,筛选到7个可能与小麦耐低磷性有关的候选基因。TraesCS6A02G001000和TraesCS6A02G001100在锌指合成中有重要作用;TraesCS6A02G118100可能为低磷胁迫诱导基因;TraesCS5D02G536400、TraesCS1B02G154200和TraesCS5D02G536500与低磷胁迫相关酶类基因家族有关;TraesCS1D02G231200与植物DUF 538结构域蛋白有关,是植物胁迫相关调控蛋白候选基因。     

普通小麦品种Hope细胞膜热稳定性基因的染色体定位

利用全部 21个“中国春”的“Hope”染色体代换系及其亲本品种“中国春” (受体)和“Hope”(供体)对六倍体普通小麦的细胞膜热稳定性基因进行了染色体定位研究。结果表明:普通小麦品种“Hope”的1A、2A、2B、 2D、3A、3B、3D、5D和6B等9条染色体上具有耐热性基因,而其余染色体与“Hope”的耐热性无关。 Abstract:All 21 substitutions of common wheat(T.aestivum L.)and their parental cultivars“Chinese Spring”(recipient)and “Hope”(donor)were evaluated for their relative heat tolerance as measured by membrane thermostability to determine the chromosomal locations of genes controlling this trait.Results indicate that chromosomes 1A,2A,2B,2D,3A,3B,3D,5D and 6B were associated with heat tolerance of cv.Hope,while the others were not related to heat tolerance.     

Genetic basis of sodium exclusion and sodium tolerance in yeast. A model for plants

A yeast strain carrying disruptions in TRK1 and ENA genes was very sensitive to Na⁺ because uptake discriminated poorly between K⁺ and Na⁺, and Na⁺ efflux was insignificant. Transformation with TRK1 and ENA1 restored discrimination, Na⁺ efflux and Na⁺ tolerance. Increasing external Ca²⁺ increased Na⁺ tolerance almost in the same proportion in TRK1 enal cells and in trkl ENAI cells, suggesting an unspecific effect of this cation. By using a vacuolar ATPase mutant, the role of the vacuole in Na⁺ tolerance was also demonstrated. The yeast model of Na⁺ exclusion and Na⁺ tolerance may be extended to plants.     

The effect of lipopolysaccharide desensitization on the regulation of in vivo induction of immunologic tolerance and antibody production and in vitro release of IL-1

As previously reported, LPS and 8-derivatized guanosine (both generators of IL-1 release), as well as IL-1 itself interfere with the in vivo induction of tolerance to DHGG in A/J mice. In the present studies it was demonstrated that desensitization of either A/J or CBA/CaJ mice with LPS aborts the ability of LPS to interfere with the induction of tolerance to DHGG. The abrogation of the ability of LPS to interfere with tolerance by LPS desensitization is not the result of neutralization of LPS by antibody produced to LPS during desensitization. Desensitization with LPS also aborts the interference with tolerance induction by 7-methyl-8-oxoguanosine. LPS desensitization inhibits the ability of LPS and/or 7-methyl-8-oxoguanosine to both convert a tolerogenic signal to an immunogenic signal and interfere with the induction of a tolerant state to a subsequent injection of Ag. The effects resulting from desensitization may be in part attributed to the depletion of IL-1. LPS desensitization also modulates the antibody response to injection of the AG, AHGG. Desensitization with LPS markedly suppresses the antibody response to a subsequent injection of AHGG in CBA/CaJ mice. Desensitization with LPS also inhibits the anti-HGG antibody response in A/J mice, but in this strain its effect is dependent on the route of injection of AHGG. In an experiment directly comparing the responses of normal and desensitized A/J mice to either intravenous or intraperitoneal injection of AHGG, desensitization only suppressed the response in mice injected with AHGG i.p.. Desensitization with LPS also inhibits the ability of LPS to act as an adjuvant in a subsequent antibody response to AHGG. Not only does desensitization interfere with the primary antibody response to AHGG, but it also interferes with the secondary response, suggesting that the primary injection after desensitization induces a state of immunologic tolerance.     

Revealing hereditary variation of winter hardiness in cereals

A set of cereal crops and differentiating cultivars was shown to be of utility for identifying the major abiotic factors that limit the survival of winter crops in the cold season of a particular year. With this approach, the season was identified (1997-1998, Belgorod) when the survival of cereals depended on the tolerance to anaerobiosis rather than on the frost resistance. Differentiation of common wheat cultivars with respect to this property was attributed to a locus designated Win1 (Winter hardiness 1) and localized 3.2-5.8% recombination away from the B1 (awnlessness) gene. Winter barley (cultivar Odesskii 165) displayed the highest tolerance to anaerobiosis in the cold season; low and intermediate tolerance was established for winter durum wheat (cultivar Alyi Parus) and winter common wheat, respectively. Frost resistance and winter hardiness type 1 proved to be determined by different genetic systems, which showed no statistical association. Correlation analysis revealed significant positive associations of frost resistance in the field (1996-1997, Belgorod) with productivity, sedimentation index, plant height, and vegetation period in wheat. Statistical analysis associated frost resistance with gliadin-coding alleles of homeologous chromosomes 1 and 6 of the A, B, and D wheat genomes.