Different Expression Patterns of the Promoters of the NgrolB and NgrolC Genes during the Development of Tobacco Genetic Tumors

Hybrids (F1) between Nicotiana glauca and N. langsdorffii areprone to develop tumorous tissues on normaltype F1 tissues,namely, genetic tumors. To investigate the patterns of expressionof Ngrol genes during the development of genetic tumors, weperformed an analysis of transgenic genetic tumors that harboredthe promoters of the NgrolB and NgrolC genes fused to a reportergene for rß-glucuronidase (GUS) using a tumorization-redifferentiationsystem derived from F1 plants in vitro. Histochemical analysis of the expression of NgrolB-GUS in normal-typeF1 transgenic plants revealed GUS activity in meristematic zones,while in NgrolC-GUS transformed plants the activity was detectedmainly in the vascular systems of various organs. Tumorous tissues,which arose spontaneously as a consequence of aging or wereinduced by cutting, showed high levels of GUS expression underthe control of promoters of both the NgrolB and the NgrolC gene.Time course analysis during tumorization that followed cuttingof leaves of normal-type F1 plants showed clearly that NgrolB-GUSwas expressed in all dividing cells in the cut region after3 days. By contrast, the expression of NgrolC-GUS was detectedin organized tissues, such as procambium in teratomatous tumors,7–10 days after cutting treatment. During redifferentiationfrom genetic tumors to normal-type plants, the expression ofGUS under control of both Ngrol promoters decreased and expressionresembled that in normal-type tissues. These results suggestthe possibility that the Ngrol genes might be involved in formationof genetic tumors and, moreover, that the expression of NgrolBmight be linked to mitosis and while that of NgrolC might berelated to differentiation of tissues, such as the vascularsystem, in F1 plants. (Received January 19, 1996; Accepted March 24, 1996)     

Cloning and Functional Expression of a Novel Geranylgeranyl Pyrophosphate Synthase Gene from Arabidopsis thaliana in Escherichia coli

A gene encoding a novel geranylgeranyl pyrophosphate (GGPP)synthase from Arabidopsis thaliana has been identified and termedGGPS5. The gene has been sequenced and expressed in Escherichiacoli. The deduced amino acid sequence showed 64.5% and 57.5%identity with a putative GGPP synthase from Arabidopsis andCapsicum annuum, respectively. GGPP enzymatic activity was detectedin E. coli cells expressing the GGPS5 gene in two differentways. One was the direct measurement of GGPP synthase activityin cell extracts and the other was the yellow color productionof cells when the GGPS5 gene was co-expressed with crtB, crtI,crtX, crtY and crtZ genes derived from Erwinia uredovora. (Received May 20, 1996; Accepted December 14, 1996)     

Mutations in the SGR4, SGR5 and SGR6 Loci of Arabidopsis thaliana Alter the Shoot Gravitropism

Shoots of higher plants grow upward in response to gravity.To elucidate the molecular mechanism of this response, we haveisolated shoot gravitropism (sgr) mutants in Arabidopsis thaliana.In this report, we describe three novel mutants, sgr4-1, sgr5-1and sgr6-1 whose inflorescence stems showed abnormal gravitropicresponses as previously reported for sgr1, sgr2 and sgr3. Thesenew sgr mutations were recessive and occurred at three independentgenetic loci. The sgr4-1 mutant showed severe defect in gravitropismof both inflorescence stem and hypocotyl but were normal inroot gravitropism as were sgr1 and sgr2. The sgr5-1 and sgr6-1mutants showed reduced gravitropism only in inflorescence stemsbut normal in both hypocotyls and roots as sgr3. These resultssupport the hypothesis that some mechanisms of gravitropismare genetically different in these three organs in A. thaliana.In addition, these mutants showed normal phototropic responses,suggesting that SGR4, SGR5 and SGR6 genes are specifically involvedin gravity perception and/or gravity signal transduction forthe shoot gravitropic response. (Received November 21, 1996; Accepted February 17, 1997)     

Chromosomal Mapping of Genes in theRBCS Family in Arabidopsis thaliana

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.     

VR-ACS6 is an Auxin-Inducible l-Aminocyclopropane-l-carboxylate Synthase Gene in Mungbean (Vigna radiata)

We have isolated four cDNA clones of ACC synthase from etiolatedmungbean seedlings treated with auxin. PVR-ACS2, pVR-ACS3 andpVR-ACS6 contained the same sequences as the previously reportedDNA fragments, pMAC2, pMAC3 (Botella et al. 1992b) and pMBAl(Kim et al. 1992), respectively. pVR-ACSl was identical withpAIM-1 (Botella et al. 1992a). VR-ACS6 was specifically induced in response to the auxin signal.The IAA-induction of VR-ACS6 was very rapid (within 30 min)and insensitive to cycloheximide treatment at concentrationsup to 100 µM. Significant accumulation of VR-ACS6 mRNAwas detected at 1 µM.IAA.The IAA-induced expression ofVR-ACS6 was suppressed by ABA and ethylene, but enhanced byBA. These characteristics of VR-ACS6 expression were well correlatedwith the physiological data of auxin-induced ethylene productionin mungbean hypocotyls. VR-ACS1 was strongly induced by cycloheximide, but was foundto be not auxin-specific. Inhibitors of either ethylene biosynthesis(AOA) or action (NBD) increased the basal level of VR-ACS1 mRNA. (Received May 7, 1996; Accepted November 25, 1996)     

Partial Characterization of a 17 kDa Acidic Protein, EFP, Induced by Thiocarbamate in the Early Flowering Phase in Asparagus Seedlings

Asparagus officinalis seedlings treated with either thiocarbamatesor carbamates are induced to flower within 2-3 weeks of application.SDS-PAGE and 2-D PAGE resolutions of total soluble proteinsof treated seedlings showed the accumulation of an acidic 17kDa polypeptide. Partialmino acid sequence of the acidic proteinshowed homology to the wound-responsive A. officinalisPR 1,AoPRl. We named this protein EFP, early flowering protein, owingto its advanced appearance during the early transition fromvegetative to floral phase. Carbamates and thiocarbamates thatinduced more than 80% flowering rates corresponded with increasedlevel of EFP while compounds that are weak flower inducers showedreduced amount of EFP. The observation thus denned the correlationshipof EFP to variable flowering rates. (Received May 27, 1996; Accepted July 11, 1996)     

Expression and Promoter Activity of Genes for Isozymes of Horseradish Peroxidase

The expression and promoter activity of genes for isozymes ofhorseradish peroxidase, namely, prxCla, prxClb, prxC2 and prxC3,were studied. Organ-specific expression of these genes in horseradishplants was examined by Northern blot analysis. The group ofprxCl genes was expressed mostly in stems, while prxC2 and prxC3were expressed to a greater extent in roots. Hardly any expressionof any of the genes was detected in leaves. In transient-expressionassays with tobacco protoplasts, about 500 bp of the 5'-noncodingregions of each of the genes, ligated to the gene for ß-glucuronidase(GUS), exhibited significant promoter activity. In particular,the fragments extending from the initiation codon of the prxC2gene to –529 bp and –1 kbp supported high levelsof GUS activity, which were 4.4 and 11.4 times respectively,the activity observed under control of the 35S promoter fromcauliflower mosaic virus (CaMV). Conserved enhancer sequencesof human genes were found in the 5'-flanking region of prxC2,and deletion of the regions that contained the enhancer sequencesreduced the GUS activity. High levels of GUS activity were observedin transgenic tobacco plants that contained 1 kbp of the 5'flanking region of prxC2 fused to the GUS gene. GUS activitywas diminished when deletion from the 5' end extended as faras the CAAT box. No significant organ-specific expression ofGUS was observed with any such deletion. (Received April 15, 1992; Accepted September 11, 1992)     

Distribution of Calanus species in Kongsfjorden, a glacial fjord in Svalbard

The distribution of Calanus species was investigated in Kongsfjordenin summer of 1996 and 1997. In both years Calanus finmarchicusand Calanus glacialis dominated, although the boreal C. finmarchicuswas more abundant than the Arctic C. glacialis in 1997. Thiscoincided with a 2°C higher water temperature at 50 m in1997, indicating stronger influence of Atlantic origin waterthat year. Advected Calanus finmarchicus occurred in deep andsubsurface layers of the outer fjord in 1996 (200 ind. m^-3,mainly CIII). A less abundant local population aggregated insurface layers of the inner fjord (100 ind. m^-3). Similarly,advected C. finmarchicus occurred in subsurface layers in 1997(446 ind. m^-3, mainly CIII and CIV) and a local population insurface layers (183 ind. m^-3, mainly CI). Calanus glacialisin 1996 aggregated as CII and CIII in the deep layers of theouter fjord (272 ind. m^-3), whereas CIII–CV were abundant(216 ind. m^-3) in cold surface waters of the inner fjord. In1997 C. glacialis (mostly CIII–CV) was more abundant inthe outer than in the inner part of the fjord (40 and 192 ind.m^-3, respectively). Within Kongsfjorden, Calanus finmarchicusneeds one year to complete its life cycle, whereas Calanus glacialisneeds two. Calanus hyperboreus seems to be an expatriate inthe fjord system.     

Rice Embryo Globulins: Amino-Terminal Amino Acid Sequences, cDNA Cloning and Expression

A globulin fraction prepared from rice embryos contained polypeptidesor polypeptide groups of 49 kDa (designated REG1), 46 kDa (designatedREG2), about 35 kDa, 32 kDa and 25 kDa. The amino-terminal sequencesof REG1 and the major polypeptide in the 35-kDa group were identical,suggesting that the REG1 polypeptide undergoes partial proteolyticprocessing that removes a carboxy-terminal region. A cDNA clone,designated pcREG2, encoding REG2 was isolated, and its nucleotidesequence was determined. The deduced amino acid sequence ofREG2 was found to be 68% identical to that of the maize GLB2globulin. Reg2 mRNA was present at high levels during embryodevelopment for up to 14 days after flowering (DAF). Lower levelswere found 20 DAF when the maturation of embryos was almostcompleted, and at the dry mature stage. Reg2 mRNA almost disappearedupon imbibition of isolated dry mature embryos but it was re-inducedat a low level by further treatment with ABA. The expressionof Reg2 was not induced by ABA in suspension-cultured cells,unlike that of Osem, one of the late embryogenesis abundantprotein (LEA) genes. (Received November 6, 1995; Accepted April 22, 1996)     

Genetic Analysis of the Effects of Polar Auxin Transport Inhibitors on Root Growth in Arabidopsis thaliana

Polar auxin transport inhibitors, including N-1-naphthylphthalamicacid (NPA) and 2,3,5-triiodobenzoic acid (TIBA), have variouseffects on physiological and developmental events, such as theelongation and tropism of roots and stems, in higher plants.We isolated NPA-resistant mutants of Arabidopsis thaliana, withmutations designated pir1 and pir2, that were also resistantto TIBA. The mutations specifically affected the root-elongationprocess, and they were shown ultimately to be allelic to aux1and ein2, respectively, which are known as mutations that affectresponses to phytohormones. The mechanism of action of auxintransport inhibitors was investigated with these mutants, inrelation to the effects of ethylene, auxin, and the polar transportof auxin. With respect to the inhibition of root elongationin A. thaliana, we demonstrated that (1) the background levelof ethylene intensifies the effects of auxin transport inhibitors,(2) auxin transport inhibitors might act also via an inhibitorypathway that does not involve ethylene, auxin, or the polartransport of auxin, (3) the hypothesis that the inhibitory effectof NPA on root elongation is due to high-level accumulationof auxin as a result of blockage of auxin transport is not applicableto A. thaliana, and (4) in contrast to NPA, TIBA itself hasa weak auxin-like inhibitory effect. (Received April 12, 1996; Accepted September 2, 1996)     

Chromosomal control of the tolerance of gradually and suddenly imposed salt stress in the Lophopyrum elongatum and wheat,Triticum aestivum L. genomes

The facultatively halophytic Lophopyrum elongatum, closely related wheat, Triticum aestivum, and their amphiploid tolerate salt stress better if they are gradually exposed to it than if they are suddenly stressed. Lophopyrum elongatum has greater tolerance of both forms of salt stress than wheat, and its genome partially confers this tolerance on their amphiploid. Chromosomal control of the tolerance of both stress regimes in the L. elongatum and wheat genomes was investigated with disomic and ditelosomic addition lines and disomic substitution lines of L. elongatum chromosomes in wheat and with wheat tetrasomics. The tolerance of the sudden salt stress is principally controlled by L. elongatum chromosomes 3E and 5E and less by 1E, 2E, 6E, and 7E and the tolerance of gradually imposed salt stress principally by chromosomes 3E, 4E, and 5E, and less by chromosome 1E and 7E. Ditelosomic analysis indicated that genes conferring the tolerance of sudden stress are on chromosome arms 1EL, 5ES, 5EL, 6EL, 7ES and 7EL and those controlling the gradual stress regime are on 1ES, 1EL, 5ES, 5EL, 6ES, 7ES, and 7EL. In wheat, chromosomes in homoeologous groups 1, 3, and 7 and chromosomes in homoeologous groups 1, 4, and 6 were shown to enhance the tolerance of suddenly and gradually imposed stress, respectively. The arms of chromosome 3E individually conferred tolerance to neither stress regime. Chromosome 2E and wheat chromosomes 2B and 2D reduce the tolerance of both stress regimes in a hyperploid state. In 2E this effect was associated with arm 2EL. A potential relationship between the tolerance of these stress regimes and the expression of the early-salt induced genes is examined.     

The Mode of Expression and Promoter Analysis of the arcA Gene, an Auxin-Regulated Gene in Tobacco BY-2 Cells

The arcA, a member of the G protein rß-subunit family,was isolated from tobacco BY-2 cells as an auxin-responsivegene. Characterization of arcA, which should help to elucidatethe function of the gene product in the plant cells, was performedwith emphasis on the mode of expression and the analysis ofits promoter. Accumulation of the arcA message was detectedonly after treatments with auxins and not after treatments withother phytohormones or CdCl₂, implying that responsiveness ofarcA was exclusive to auxin. The putative arcA promoter regionwas fused to a reporter gene for rß-glucuronidase(GUS), and transient expression was analyzed in tobacco BY-2cells. Two series of arcA promoter/GUS chimeric genes were constructed.One consisted of a set of 5' nested deletions of the arcA promoterconnected to the gene for GUS and the other consisted of a varietyof the arcA promoter fragments fused to a minimal promoter-GUSconstruct. The results indicated that the promoter sequencecovering four sets of direct repeats (– 562 to –167)was necessary for the sufficient response of arcA promoter toauxin in BY-2 cells. Moreover, irrespective of auxin treatment,elevated activity of GUS driven by this promoter fragment wasdetected, a result that implies that this region behaves anenhancer in BY-2 cells. (Received September 30, 1995; Accepted March 1, 1996)     

Expression of Plasma Membrane Water Channel Genes under Water Stress in Nicotiana excelsior

Deduced amino acid sequences encoded by the cDNAs related tothe MIP gene family from Nicotiana excelsior were characterized.Phylogenetic characterization of the products of correspondinggenes named NeMip1, NeMip2, and NeMip3 strongly suggested thatthey are water channel proteins localized in the plasma membrane.Organ specificity of the gene expression was examined in leaves,roots, and reproductive organs. NeMip1 was expressed in rootsand reproductive organs; however, it was hardly detectable inleaves. Two other genes, NeMip2 and NeMip3, were expressed inall of organs examined. mRNA accumulation from the genes wasinvestigated in leaves under salt- and drought-stresses. Theresults demonstrated that mRNA accumulation from all three genesincreased under salt- and drought-stresses within one day. However,they showed different accumulation patterns. In addition totheir up-reg-ulation under salt- and drought-stresses, dailychanges in NeMip2 and NeMip3 mRNA accumulation was observedunder unstressed conditions in leaves. (Received May 2, 1997; Accepted September 3, 1997)     

云南蚊科三新种 （双翅目：蚊科）

记述了采自云南蚊科3新种,即：蓝带蚊属伪费蚊亚属一新种瞿氏蓝带蚊Uranotaenia (Pseudoficalbia) qui Dong, Dong et Zhou, sp. Nov.,采自西双版纳优乐山竹穴积水中,与新糊蓝带蚊Ur. Novobscura Barraud和二斑蓝带蚊Ur. Bimaculata Leicester近缘;领蚊属一新种类孟连领蚊Heizmannia (Heizmannia) menglianeroides Dong, Dong et Zhou, sp. Nov.,采自云南省景洪县森林竹筒积水中,与孟连领蚊Hz. Menglianensis Lu et Gong, 1986为近缘;库蚊属泰蚊亚属一新种陈氏库蚊Culex (Thaiomyia) cheniDong, Wang et Lu, sp. Nov.,采自云南西北部海拔1795 m的腾冲县竹筒积水,与海南库蚊Cu. (Th.) hainaensis Chen, 1977近缘。讨论了各新种与近缘种的鉴别特征。新种分别存放在云南省疟疾防治研究所和贵阳医学院微生物教研室。     

Identification of Open Reading Frames in Schizosaccharomyces pombe cDNAs

A total of 214 non-overlapping cDNA clones from Schizosaccharomycespombe were selected and completely sequenced. The clones notpreviously reported were divided into the following three groups:1) homologous to Saccharomyces cerevisiae genes (139 clones);2) homologous to genes from other organisms but not to thosefrom Sac. cerevisiae (4 clones); and 3) no similar sequences(40 clones). Among the 31 sequences identical to those in thepublic databases, 4 genes have regions corresponding to introns.Protein sequences which had homologs both in budding yeast andmammals were compared with those from Sac. cerevisiae and mammals.The search revealed that the evolutionary distances among thesespecies are similar at least with genes of this category.     

A NEW METHOD FOR RECORDING THE IN SITU PUMPING ACTIVITY OF INFAUNAL BIVALVES

A new method for measuring the pumping activity of infaunalbivalves is described. The method is based on the simultaneousrecording of three temperatures: (1) the temperature of thesea water above the bivalve, (2) the temperature of the sedimentand (3) the internal temperature of the bivalve. When thermicshifts between sediment and sea water are induced by the sunand/or the ground water, comparison of the three temperaturesprovides information on the pumping activity of the bivalve.The method was applied during the day to Tapes decussatus andRuditapes philippinarum (Veneridae). Their pumping activityappears continuous except during emersion at ebb. Sestonic concentrationsas high as 325 mg 1^–1 induced no detectable interruption.Analysis of the data suggests that in situ pumping rate is notconstant but fluctuates. (Received 14 February 1996; accepted 15 May 1996)