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1.
A carrot gene homologous to the ABI3 gene of Arabidopsis wasisolated from a carrot somatic embryo cDNA library and designatedC-ABI3. The sequence of C-ABI3 was very similar to those ofABI3 of Arabidopsis and VP1 of maize in certain conserved regions.The expression of C-ABI3 was detected specifically in embryogeniccells, somatic embryos and developing seeds. Thus, expressionof C-ABI3 was limited to tissues that acquired desiccation tolerancein response to endogenous or exogenous abscisic acid (ABA).Endogenous levels of ABA in seeds increased transiently andthen desiccation of seeds started. The expression of C-ABI3in developing seeds was observed prior to the increase in levelsof endogenous ABA that was followed by desiccation of seeds.In transgenic mature leaves in which C-ABI3 was ectopicallyexpressed, expression of ECP31, ECP63 and ECP40 was inducedby treatment with ABA, which indicates that the expression ofECP genes was controlled by the pathway(s) that involved C-ABI3and ABA. This suggests that C-ABI3 has the same function asVP1/ABI3 factor in carrot somatic embryos. (Received March 4, 1998; Accepted September 4, 1998)  相似文献   

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The Japanese morning glory carrying the recessive mutable speckledallele with the dominant speckled-activator bears colorlessflowers with fine and round colored spots distributed over thecorolla whereas the plant without the speckled-activator producespale yellow flowers. Previous chemical analysis has indicatedthat a mutation in the gene for flavanone 3-hydroxylase (F3H)is a likely candidate for the speckled allele. However, theF3HmRNA without sequence alteration accumulates normally inthe pale yellow flowers, indicating that the speckled alleleis neither the F3H gene nor a regulatory gene acting on theF3H gene expression. (Received April 4, 1997; Accepted June 2, 1997)  相似文献   

4.
Four cDNA clones were isolated from Vigna mungo seedlings bythe screening with cDNA encoding UDP-glu-cose:flavonoid 3-0-glucosyltransferase(UF3GT) of Antirrhinum majus as a probe; the product of thegene corresponding to one cDNA was more highly expressed inthe first simple leaves than in stems. Nucleotide sequence analysisrevealed 1,691 bp (including 326 bp non-reading) containingan open reading frame of 455 amino acids. The deduced aminoacid sequence showed 42% and 23% identity with those of A. majusUDP-glucose:flavonoid 3-O-glucosyltransferase (UF3GT) and Petuniahybrida UDP-rhamnose:anthocyanidin 3-0-glucoside rhamnosyltrans-ferase(RT), respectively. One region of the cDNA (amino acids 325to 387) showed similarity to ceramide UDP-galac-tosyltransferasesof mice, rats and humans. A crude extract from Escherichia coli,in which the protein was expressed from the cDNA, showed highUF3GaT activity but low UF3GT activity, and was similar in Km,optimal pH and substrate specificity to UF3GaT from V. mungo.We conclude that we have obtained UDP-galactose:flavonoid 3-0-galactosyltransferase(UF3GaT) cDNA from V. mungo. 4 Deceased.  相似文献   

5.
All eight isolines of three maturity genes (E1/e1, E2 /e2, andE3 /e3) of soyabean [Glycine max (L.) Merrill] cv. Clark weregrown in widely different combinations of photoperiod and temperature.Under the more inductive conditions, i.e. in a warm mean temperature(30°C) when daylengths were less than the critical value(i.e. less than about 13 h), the isolines flowered at similartimes (23-24 d). The responses of all isolines to temperaturewere also similar, if not identical. Increase in daylength abovethe critical photoperiod progressively delayed flowering untilthe time taken to flower (f) reached a maximum at the ceilingphotoperiod. The relations between the rate of progress towardsflowering (1/f) and photoperiod (between the critical and ceilingvalues) were linear. The coefficient characterizing the slopeof the response (photoperiod sensitivity) varied amongst theisolines. These responses could be grouped into three categoriesof increasing sensitivity: (1) least sensitive, e1e2e3 , e1E2e3, e1e2E3 ; (2) intermediate, E1e2e3 , e1E2E3 ; and (3) mostsensitive, E1E2e3, E1e2E3 , E1E2E3 . Thus, in the Clark cultivargenetic background, E1 induces greater photoperiod sensitivitybut neither E2 nor E3 on their own have any effect. However,both E2 and E3 together induce photoperiod sensitivity comparableto that induced by E1 alone. Furthermore, in addition to thisepistasis, either E2 or E3 has considerable epistatic effecton E1, further increasing photoperiod sensitivity. The effectsof these genes and their epistasis were also reflected in theextent of the maximum delays to flowering which occur when theceiling photoperiod is exceeded, and also possibly in earlinessin circumstances when photoperiods were below the critical value.Copyright1994, 1999 Academic Press Glycine max (L.) Merrill, soyabean, maturity genes, flowering, photoperiod, temperature  相似文献   

6.
The effects of different applied NO3 concentrations onextension growth and final length and area of leaves 1–4of five cereals and six pasture grasses of temperate originwere examined. Increased applied NO3 in the range 0.1–50mol m–3; caused decreased duration of growth but increasedgrowth rate and final length of leaves 2–4 of the cerealsAvena saliva, Hordeum vulgare, Secale cereale x Triticosecaleand Triticum aestivum. For all cereals, increased NO3resulted in increased area of leaves 1-4. Pasture grasses weresupplied either 0.5 or 50 mol m–3; NO3. Increasedapplied NO3 (0.5–50 mol m–3) resulted indecreased duration of growth and increased growth rate and finalarea of leaves 1–4 of Bromus willdenowii leaves 2–4of Festuca arundinaceae and leaves 3 and 4 of Lolium multiflorum.In addition, length of leaves 3 and 4 of B. willdenowii increasedwith increased NO3. Increased NO3 resulted in increased areaof leaves 2–4 of Daciylis glomerata and Lolium perenneand leaves 3 and 4 of Phalaris aquatica but had no effect onextension growth of all three species. Avena saliva L., oat, Hordeum vulgare L., barley, Secale cereaie L., rye, x Triticosecale Wittm, triticale, Triticum aestivum L., wheat, Bromus willdenowii Kunth, prairie grass, Dactylis glomerata L., cocksfoot, Festuca arundinaceae Shreb, tall fescue, Lolium multiflorum Lam, Italian ryegrass, Lolium perenne L, perennial ryegrass, Phalaris aquatica L, nitrate,, leaf extension, leaf expansion  相似文献   

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The effects of different applied NO3 concentrations onextension growth and final length and area of leaves 1–4of five cereals and six pasture grasses of temperate originwere examined. Increased applied NO3 in the range 0.1–0.5.0mol m–3 caused decreased duration of growth but increasedgrowth rate and final length of leaves 2–4 of the cerealsAvena saliva, Hordeum vulgare, Secale cereale, x Triticosecaleand Triticum aestivum. For all cereals, increased NO3resulted in increased area of leaves 1–4. Pasture grasseswere supplied either 0.5 or 50 mol m–3 NO3. Increasedapplied NO3 (0.5–5.0 mol m–3) resulted indecreased duration of growth and increased growth rate and finalarea of leaves 1–4 of Bromus wiltdenowii, leaves 2–4ofFestuca arundinaceae and leaves 3 and 4 of Lolium muitiflorum.In addition, length of leaves 3 and 4 of B. witidenowii increasedwith increased NO3. Increased NO3 resulted inincreased area of leaves 2–4 of Dactylis gtomerata andLolium perenne and leaves 3 and 4 of Phalaris aquaiica but hadno effect on extension growth of all three species. Avena sativa L, oat, Hordeum vulgare L, barley, Secale cereale L, rye, x Triticosecale Wittm, triticale, Triticum aestivum L, wheat, Bromus willdenowii Kunth, prairie grass, Dactylis gtomerata L, cocksfoot, Festuca arundinaceae Shreb, tall fescue, Lolium multijlorum Lam, Italian ryegrass, Lolium perenne L, perennial ryegrass, Phalaris aquatica L, nitrate, leaf extension, leaf expansion  相似文献   

9.
Plants of four isolines of soyabean [Glycine max(L.) Merrill]‘Clark’, viz‘L71-920’ (maturity genecomplemente1e2e3 ), ‘L80-5914’ (E1e2e3), ‘Clark’(e1E2E3), and ‘L65-3366’ (E1E2E3), were grown inshort (12.25 h d - 1natural light) and long days (12.25 h d- 1natural light supplemented with 2.75 h d - 1low-irradianceartificial light) from first flowering to maturity in a polythenetunnel maintained at 30/24°C (day/night). Whereas therewere few differences among the isolines grown in short days,in long days the dominant alleles increased crop duration, biomassand seed yield substantially. Increases in biological and economicyield were not solely a consequence of longer crop duration:the dominant alleles also increased crop growth rate and radiationuse efficiency in long days (from 1.3 g MJ - 1total radiationine1e2e3 to 2.8 g MJ - 1inE1E2E3 ). Greater radiation use efficiencyresulted from a relatively longer leaf area duration, betterdistribution and orientation of a larger mass of leaves withinthe canopy, and smaller partitioning of assimilates to reproductivestructures. The work reveals the substantial effects of thethree lociE1 / e1, E2/ e2and E3/e3 on the response of plantgrowth, as well as development, to environment. Their relevanceto crop adaptation is discussed. Copyright 2000 Annals of BotanyCompany Glycine max(L.) Merrill, soyabean, maturity genes, flowering, phenology, growth, yield  相似文献   

10.
Using theblood-free perfused rat brain, we examined the redox behavior ofcytochrome oxidase of two chromophores, hemeaa3 and copper.When perfusate inflow was stopped to induce global ischemia,the reduction of heme a + a3 was triphasic,with a rapid phase, a slow phase, and a second rapid phase. Incontrast, the reduction of copper was monophasic after the rapid phaseof heme a + a3. The triphasicreduction of heme a + a3 was diminished by energy-depleting treatments, such as addition of an uncoupler. Thetime course of the reduction of copper was not affected by the energydepletion. During global ischemia the decrease in creatine phosphate nearly paralleled the reduction of hemea + a3, whereas ATPremained at the control level until ~60% of hemea + a3 was reduced inthe rapid phase. In the slow phase, ATP started to decrease with thereduction of copper. The redox behavior of copper was similar to theslow phase of the reduction of heme a + a3 because ofthe higher oxygen affinity of copper than of hemeaa3. Therefore,the rapid phase of the reduction of hemea + a3 can be used asan alarm before a decrease in ATP, whereas the reduction of copperindicates a decrease in ATP under severe hypoxia. Thus the coppersignal in noninvasive near-infrared spectroscopy is a useful parameterfor the clinical setting.

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Nitrate reductase activity (NRA, in vivo assay) and nitrate(NO-3) content of root and shoot and NO-3 and reduced nitrogencontent of xylem sap were measured in five temperate cerealssupplied with a range of NO-3 concentrations (0·1–20mol m–3) and three temperate pasture grasses suppliedwith 0·5 or 5 0 mol m–3 NO-3 For one cereal (Hordeumvulgare L ), in vitro NRA was also determined The effect ofexternal NO-3 concentration on the partitioning of NO-3 assimilationbetween root and shoot was assessed All measurements indicatedthat the root was the major site of NO3 assimilation in Avenasatwa L, Hordeum vulgare L, Secale cereale L, Tnticum aestivumL and x Triticosecale Wittm supplied with 0·1 to 1·0mol m–3 NO-3 and that for all cereals, shoot assimilationincreased in importance as applied NO-3 concentration increasedfrom 1.0 to 20 mol m–3 At 5.0–20 mol m–3 NO3,the data indicated that the shoot played an important if notmajor role in NO-3 assimilation in all cereals studied Measurementson Lolium multiflorum Lam and L perenne L indicated that theroot was the main site of NO-3 assimilation at 0.5 mol m–3NO-3 but shoot assimilation was predominant at 5.0 mol m–3NO-3 Both NRA distribution data and xylem sap analysis indicatedthat shoot assimilation was predominant in Dactylis glomerataL supplied with 0.5 or 5.0 mol m–3 NO-3 Avena sativa L., oats, Hordeum vulgare L., barley, Secale cereale L., rye, x Triticosecale Wittm., triticale, Triticum aestivum L., wheat, Dactylis glomerata L., cocksfoot, Lolium multiflorum Lam., Italian ryegrass, Lolium perenne L., perennial ryegrass, nitrate, nitrate assimilation, nitrate reductase activity, xylem sap  相似文献   

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Cloning and characterization of the ALG3 gene of Saccharomyces cerevisiae   总被引:2,自引:0,他引:2  
The Saccharomyces cerevisiae alg3-1 mutant is descilbed as defectivein the biosynthesis of dolichol-linked oligosaccharides (Huffakerand Robbins, Proc. Natl. Acad. Sci. USA, 80, 7466–7470,1983). Man5GlcNAc2-PP-Dol accumulates in alg3 cells and EndoH resistant carbohydrates are transferred to protein by theoligosaccharyltransferase complex. In this study, we describethe cloning of the ALG3 locus by complementation of the temperaturesensitive growth defect of the alg3 stt3 double mutant. Theisolated ALG3 gene complements both the defect in the biosynthesisof lipidlinked oligosaccharides of the alg3-mutant and the underglycosylationof secretory proteins. The inactivation of the nonessentialALG3 gene results in the accumulation of lipid-linked Man5GlcNAc2and protein-bound carbohydrates which are completely Endo Hresistant. The ALG3 locus encodes a potential ER-transmembraneprotein of 458 amino acids (53 kDa) with a C-terminal KKXX-retrievalsequence. lipid-linked oligosaccharide N-glycosylation synthetic lethality  相似文献   

16.
In Arabidopsis thaliana, four genes have been identified inthe RBCS gene family, one being assigned to subfamily RBCS-Aand the other three to subfamily RBCS-B (1B, 2B and 3B). Todetermine the chromosomal location ofthese genes, hybridizationanalysis with CIC YAC high-density filters was carried out forthe RBCS-A gene, and CAPS analysis for the three RBCS-B genes,based on the finding that restriction fragment length polymorphismis present in the upstream region of the gene RBCS-3B. The RBCS-Agene was mapped at 100.8 cM from the top of chromosome 1 andthe three RBCS-B genes at 62.70 cM from the top of chromosome5.  相似文献   

17.
The structure of the zooplankton biotic community and of copepodpopulation in the coastal area of Terra Nova Bay (Ross Sea,Antarctica) was investigated during the 10th Italian AntarcticExpedition (1994/1995). Zooplankton biotic community consistedmainly of pteropods (Limacina helicina and Clione antarctica),Cyclopoid (Oithona similis), Poecilostomatoid (Oncaea curvata)and Calanoid (Ctenocalanus vanus, Paraeuchaeta antarctica, Metridiagerlachei and Stephos longipes) copepods, ostracods, larvalpolychaetes and larval euphausiids. Zooplankton abundance rangedfrom 48.1 ind m–3 to 5968.9 ind m–3, and copepodabundance ranged from 45.2 ind m–3 to 3965.3 ind m–3.The highest peak of zooplankton abundance was observed between25 m and the surface and was mainly due to the contributionof O. similis, O. curvata and C. vanus. Zooplankton biomassranged from 5.28 mg m–3 to 13.04 mg m–3 dry weight;the maximum value was observed between 25 m and the surface.Total lipid content varied from 216.44 to 460.73 mg g–1dry weight.  相似文献   

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The galectin family of β-galactoside binding lectins isinvolved in normal and pathological processes. Altered expressionof galectin-3 has been described in many cancers, and studiesof cancer cell lines have implicated this lectin in variousaspects of the tumorigenic cascade. The goal of this reportwas to directly assess the importance of galectin-3 in tumorbiology by introducing the galectin-3 null mutation (galectin-3–/–)into mouse lines genetically programmed to develop cancers.We used two mouse models of human intestinal cancer, the ApcMinand Apc1638N lines, to study tumor initiation and tumor progression.We also crossed the galectin-3–/– mice with PyMTtransgenic animals, a model in which primary mammary gland tumorsgive rise to lung metastases at high frequency. Unexpectedly,we show that the absence of galectin-3 does not affect the evolutionof the disease in any of these three situations.  相似文献   

20.
To study the role of metallothioneins (MTs) in Zn accumulation,the expression of TcMT2a, TcMT2b, and TcMT3 was analysed inthree accessions and 15 F3 families of two inter-accession crossesof the Cd/Zn hyperaccumulator Thlaspi caerulescens, with differentdegrees of Zn accumulation. The highest expression levels werefound in the shoots of a superior metal-accumulating calamineaccession from St Laurent le Minier, with >10-fold TcMT3expression compared with another calamine accession and a non-metallicolousaccession. Moreover, F3 sibling lines from the inter-accessioncrosses that harboured the MT2a or MT3 allele from St Laurentle Minier had higher expression levels. However, there was noco-segregation of TcMT2a or TcMT3 expression and Zn accumulation.To examine the functions of TcMTs in plants, TcMT2a and TcMT3were ectopically expressed in Arabidopsis. The transformantlines had reduced root length in control medium but not at highmetal concentrations, suggesting that the ectopically expressedproteins interfered with the physiological availability of essentialmetals under limited supply. The Arabidopsis transformant linesdid not show increased tolerance to Cd, Cu, or Zn, nor increasedCd or Zn accumulation. Immunohistochemical analysis indicatedthat in roots, MT2 protein is localized in the epidermis androot hairs of both T. caerulescens and Arabidopsis thaliana.The results suggest that TcMT2a, TcMT2b, and TcMT3 are not primarilyinvolved in Zn accumulation as such. However, the elevated expressionlevels in the metallicolous accessions suggests that they docontribute to the metal-adapted phenotype, possibly throughimproving Cu homeostasis at high Zn and Cd body burdens. Alternatively,they might function as hypostatic enhancers of Zn or Cd tolerance. Key words: Cd, crosses, metallothionein, protein, quantitative real-time PCR, Thlaspi caerulescens, Zn Received 14 August 2008; Revised 14 October 2008 Accepted 15 October 2008  相似文献   

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