The effect of caffeine,different fixation regimes and low temperature on microtubules in the cells of higher plants

Caffeine, (1:3:7-tri-methyl-xanthine), either as a prefixation treatment or included with glutaralde-hyde as the primary fixative, destroys or disorganises the microtubules associated with the formation of secondary walls in fibres from the flowering stem of the grass Lolium temulentum L. There is no observable effect of caffeine treatment on the microtubules associated with primary wall formation in collenchyma and young fibres from L. temulentum or in root cap cells of Zea mays L. and Phaseolus vulgaris L. The microtubules associated with primary wall formation are destroyed by cold treatment but not those associated with secondary wall formation. Tannic acid included in the fixative shows the microtubules associated with secondary wall formation in fibres of L. temulentum to be composed of 13 subunits. Treatment with lanthanum hydroxide does not stain the core or the halo of the microtubules.Abbreviation PIPES Piperazine N-N- bis 2 ethanol sulphonic acid The Grassland Research Institute is financed through the Agricultural Research Council     

Survey ofLymantria obfuscata and its natural enemies in India

The status ofLymantria obfuscata Walker in India is discussed. Notes on its taxonomy, distribution, life-history and economic importance are given for comparison with those of the gypsy moth,Lymantria dispar (L.). Parasites ofL. obfuscata in India are reviewed. A survey in 1961–66 revealed an additional 50 species of natural enemies ofL. obfuscata in India. The incidence and biology of some of the important ones are presented. A comparison is made between these parasites and those ofL. dispar. Some of the natural enemies ofL. obfuscata already attackL. dispar in America. Others are closely related to the parasites of the gypsy moth. The scope for utilisation of parasites ofL. obfuscata in other countries is discussed. Possible use of parasites ofL. dispar from the U.S.A. or elsewhere againstL. obfuscata in India is suggested. Research financed in part by the U.S.D.A. under grant PL-480.     

Neural organisation in the first optic ganglion of the nocturnal bee <Emphasis Type="Italic">Megalopta genalis</Emphasis>

Each neural unit (cartridge) in the first optic ganglion (lamina) of the nocturnal bee Megalopta genalis contains nine receptor cell axons (6 short and 3 long visual fibres), and four different types of first-order interneurons, also known as L-fibres (L1 to L4) or lamina monopolar cells. The short visual fibres terminate within the lamina as three different types (svf 1, 2, 3). The three long visual fibres pass through the lamina without forming characteristic branching patterns and terminate in the second optic ganglion, the medulla. The lateral branching pattern of svf 2 into adjacent cartridges is unique for hymenopterans. In addition, all four types of L-fibres show dorso-ventrally arranged, wide, lateral branching in this nocturnal bee. This is in contrast to the diurnal bees Apis mellifera and Lasioglossum leucozonium, where only two out of four L-fibre types (L2 and L4) reach neighbouring cartridges. In M. genalis, L1 forms two sub-types, viz. L1-a and L1-b; L1-b in particular has the potential to contact several neighbouring cartridges. L2 and L4 in the nocturnal bee are similar to L2 and L4 in the diurnal bees but have dorso-ventral arborisations that are twice as wide. A new type of laterally spreading L3 has been discovered in the nocturnal bee. The extensive neural branching pattern of L-fibres in M. genalis indicates a potential role for these neurons in the spatial summation of photons from large groups of ommatidia. This specific adaptation in the nocturnal bee could significantly improve reliability of vision in dim light. B.G. is grateful for travel awards from the Royal Physiographic Society, the Per Westlings Fond, the Foundation of Dagny and Eilert Ekvall and the Royal Swedish Academy of Sciences. E.J.W. acknowledges the receipt of a Smithsonian Short-Term Research Fellowship and thanks the Swedish Research Council, the Crafoord Foundation, the Wenner–Gren Foundation and the Royal Physiographic Society of Lund for their ongoing support. W.T.W. was supported by general research funds from the Smithonian Tropical Research Institute     

Endosperm dosage relationships among Lycopersicon species

Summary Accessions of eight Lycopersicon species and five yellow-flowered Solanum species were used as males in crosses with 2x and 4x L. esculentum to observe seed set and progeny ploidy. Species which failed in crosses to L. esculentum were crossed as males to 2x and 4x L. peruvianum. In cases of low seed set, chromosome counts were undertaken to establish the nature of the progeny. Endosperm Balance Number (EBN) relationships were determined for the crossability groups. Results support the basic concept of an L. esculentum crossability complex and an L. peruvianum crossability complex. Within the L. esculentum complex, all EBNs appear identical with a value of 2. Within the L. peruvianum complex, more variability appears to exist. The EBN values of this group are higher, and may be approximately double those of the L. esculentum complex. The EBN of L. peruvianum var humifusum appears to be somewhat lower than other L. peruvianum types. The EBN values of S. lycopersicoides, S. rickii, S. ochranthum and S. juglandtfolium could not be determined experimentally. Differential aspects of Lycopersicon and tuber-bearing Solanum evolution may be interpreted on the basis of endosperm compatibility.Co-operative investigation of the Vegetable Crops Research Unit, U.S. Department of Agriculture, Agricultural Research Service, and the Wisconsin Agricultural Experiment Station     

L-Fucose production by engineered Escherichia coli

L -Fucose (6-deoxy-L -galactose) is a major constituent of glycans and glycolipids in mammals. Fucosylation of glycans can confer unique functional properties and may be an economical way to manufacture L -fucose. Research can extract L -fucose directly from brown algae, or by enzymatic hydrolysis of L -fucose-rich microbial exopolysaccharides. However, these L -fucose production methods are not economical or scalable for various applications. We engineered an Escherichia coli strain to produce L -fucose. Specifically, we modified the strain genome to eliminate endogenous L -fucose and lactose metabolism, produce 2′-fucosyllactose (2′-FL), and to liberate L -fucose from 2′-FL. This E. coli strain produced 16.7 g/L of L -fucose with productivity of 0.1 g·L⁻¹·h⁻¹ in a fed-batch fermentation. This study presents an efficient one-pot biosynthesis strategy to produce a monomeric form of L -fucose by microbial fermentation, making large-scale industrial production of L -fucose feasible.     

Electrophoretic variability in island populations of Drosophila simulans and Drosophila immigrans

Genetic structure and variability were investigated in several Hawaiian populations of D. simulans and D. immigrans. Genetic variability is lower in Hawaiian populations of D. simulans than in Texas populations, and allelic differences exist as well. For D. immigrans, Hawaiian and Korean populations are similar in variability, allelic content, and gene frequencies. Several hypothesis are advanced to account for the patterns in gene variation observed between island and continental populations of these two colonizing species.This research was supported by Grant GB-23230 to the Hawaii Subprogram of the International Biology Program, by Grant GB-27586 to Dr. H. L. Carson, and by the Research Board of the School of Life Sciences, University of Illinois, Urbana, Illinois.Technical Report No. 57 of the U.S. IBP, Hawaii Integrated Research Program.     

Germination salt resistance of alfalfa (Medicago sativa L.) germplasm in relation to subspecies and centers of diversity

Saline soils and water severely limit the productivity of crop and pasture lands in semiarid and arid environments. The breeding of salt resistant cultivars of some crops is a partial solution to this problem. To breed for increased salt resistance, scientists must characterize the potentials and limitations of germplasm resources. This study measured the salt resistance of 761 alfalfa (Medicago sativa L. Emend. Sensu Lato) plant introduction accessions to NaCl during germination and characterized the resistance by subspecies, country of origin, and center of diversity. Experiments indicated that germplasm from the arid Indian and African centers excelled in NaCl resistance during germination. Germplasm from the Falcata center was least resistant. M. sativa L. subsp. sativa was more than twice as resistant as M. sativa L. subsp. ambigua or subsp. falcata. Thus, more resistant germplasm potentially adapted to the warm desert regions is available than resistant germplasm better suited to alfalfa production in more temperate regions. Joint contribution of the USDA-Agricultural Research Service and the Utah Agricultural Experimental Station Journal Paper no. 3782. Joint contribution of the USDA-Agricultural Research Service and the Utah Agricultural Experimental Station Journal Paper no. 3782.     

Ultimobranchial gland ultrastructure of larval axolotls,Ambystoma mexicanum shaw,with some observations on the newt,Pleurodeles waltlii Micahelles

Summary The fine structure of the ultimobranchial (UB) glands of two common laboratory urodeles, viz., larval axolotls, Ambystoma mexicanum Shaw and adult Pleurodeles waltlii Micahelles, is described and compared in what is believed to be the first ultrastructural report on urodele UB glands. The axolotl UB gland shows a wide variety of form, being represented by an elongated diffuse series of follicles and sometimes by one or two large discrete terminal follicular bodies. In these axolotl UB glands up to four cell categories are distinguishable including a tonofilamentous cell and a secretory cell that is possibly homologous with calcitonin-producing C cells of anurans or other vertebrates. These two cell categories are also found in the Pleurodeles gland. The possible significance of the various cells is considered.We are indebted to the Central Research Fund of London University and the Science Research Council for awards making this research possible. We would also like to thank Dr. Eyal of the Dept. of Zoology, The Hebrew University, Jerusalem for the gift of the Pleurodeles and Mr. Raynor L. Jones for his excellent technical assistance.     

Ultrastructure of the pericardium in chitons (Mollusca: Polyplacophora), in relation to filtration and contraction mechanisms

Summary The pericardium in Lepidopleurus asellus (Spengler), Tonicella marmorea (Fabricius), T. rubra L., Ischnochiton albus L., and Calleochiton laevis (Montagu), species taxonomically far apart, is described. It consists of a flat, simple epithelium facing the pericardial cavity, a basement membrane, a muscle layer with two types of muscle fibres, nerve processes, glio-interstitial cells, and fibrocytes, embedded in a loose collagen matrix. The epithelium in L. asellus and I. albus have convoluted lateral cell borders, and in L. asellus very long basal cell processes are seen. Type 1 muscle fibres resemble smooth molluscan muscle. Type 2 muscle fibres resemble cardiac muscle fibres in chitons. Nerve processes associated with glio-interstitial cells and cell processes, run free in the matrix. Synapses in type 1 fibres are covered with glio-interstitial cell processes, lacking in type 2 muscle fibres synapses.This work was supported by grants from the Norwegian Research Council for Science and the Humanities     

Effects of age on the acquisition of agreement inflection

Grammaticality judgement tasks show that second language learners who started during childhood are significantly more accurate on judging inflection than learners who started after puberty [Johnson, J., & Newport, E. (1989). Cognitive Psychology, 21, 60–99; Johnson, J., & Newport, E. (1991). Cognition, 39, 215–258; McDonald, J. (2000). Applied Psycholinguistics, 21, 395–423. Production data confirmthat inflection is a bottleneck in adult language acquisition, and that they differ from child learners in this respect [Lardiere, D. (1998). Second Language Research, 14, 359–375; Prévost, P. (2003). Studies in Second Language Acquisition, 25, 65–97; Pre vost, P., & White, L. (2000). Second Language Research, 16(2), 103–133]. Although the observations suggest that the acquisition of inflection is influenced by age, there is no study that focuses on this particular issue nor is there an articulated explanation available for the observed age-related difference. In this contribution, we compare child L2 learners of Dutch to child L1 and adult L2 learners of Dutch in order to investigate effects of age on the acquisition of verbal and adjectival inflection. We hypothesize that adult agreement paradigms differ from child agreement paradigms, the reason being that adult learners cannot rely on syntactic cues, whereas children make reliable use of syntax in building paradigms. By effect, adult learners end up with non-targetlike small paradigms that contain underspecified suffixes. We focus on the types of errors in the three learner groups (child L1, child L2 and adult L2). Our empirical basis consists of results obtained in a series of production experiments. An erratum to this article can be found at     

Differential foliar responses of northern hardwoods to fertilization

A 70-year-old thinned northeastern Fagus-Betula-Acer stand in the Adirondack Mountains of northern New York was fertilized with varying combinations of N, P, K, and lime in the spring of 1976.Betula alleghaniensis Brit.,Acer saccharum Marsh.,Acer rubrum L., andFagus grandifolia Ehrh. foliage was collected in the autumn for 1974 through 1977 and analyzed for foliage areas and weights, and levels of ash, N, P, K, Ca, Mg, Mn, Na, Fe, Zn, Al, Cu, and Co. Comparisons are made within species and among treatments, expressed as concentrations on a dry weight basis. Elemental composition is examined to determine the differential foliar responses to fertilization.Contribution of State University of New York College of Environmental Science and Forestry, Syracuse, New York, 13210.The authors are Graduate Research Assistant, Director of Huntington Forest, Technical Research Assistant, and Professor of Forest Soil Science (now deceased), SUNY, respectively.     

Proteinase inhibitors I and II in fruit of wild tomato species: Transient components of a mechanism for defense and seed dispersal

The juice of unripe fruit from a wild species of tomato, Lycopersicon peruvianum (L.) Mill., LA 107, contains over 50% of its soluble proteins as the sum of two proteinase inhibitors. These are the highest levels of proteinase inhibitors and highest percentage of soluble proteins as proteinase inhibitors of any plant or animal tissue found to date. Fruit of the modern tomato, L. esculentum Mill., contains only negligible quantities of the two inhibitors. The two proteinase inhibitors in the fruit of L. peruvianum are members of the Inhibitor I and II families previously found in potato tubers and in leaves of wounded potato and tomato plants. The levels of the two inhibitors in the unripe fruit decrease significantly during ripening. Unripe fruit from other wild Lycopersicon species such as L. parviflorum Rick, Kesicki, Fobes et Holle, L. hirsutum Humb. et Bonpe., L. pimpinellifolium Mill., and other lines of L. peruvianum contain moderate levels of the inhibitors that also decrease during ripening. Another wild tomato species, L. pennellii Corr., is similar to L. esculentum in not containing the two proteinase inhibitors in either unripe or ripe fruit. The transient levels of the inhibitors in fruit of wild species indicate that they are present in unripe fruit as defensive chemicals against insects, birds or small mammals and their disappearance during ripening may render them edible to facilitate seed dispersal. High levels of mRNAs coding for Inhibitors I and II in unripe fruit of L. peruvianum, LA 107, indicate that strong promoters may regulate the developmentally expressed proteinase-inhibitor genes in tomato fruit that may have a substantial potential for use in genetic-engineering experiments to enhance the production of large quantities of proteinase inhibitors or other proteins in field tomatoes.Abbreviations poly(A)⁺ mRNA polyadenylated mRNA - SDS-PAGE sodium dodecyl sulfate-polyacrylamide electrophoresis Project 1791, College of Agriculture and Home Economics Research Center, Washington, State University     

The cellular pathway of sucrose transport in developing cotyledons ofVicia faba L. andPhaseolus vulgaris L.: a physiological assessment

The cellular pathway of sugar uptake in developing cotyledons of Vicia faba L. and Phaseolus vulgaris L. seed was evaluated using a physiological approach. The cotyledon interface with the seed coat is characterised by a specialised dermal cell complex. In the case of Vicia faba cotyledons, the epidermal component of the dermal cell complex is composed of transfer cells. Sucrose is the major sugar presented to the outer surface of both cotyledons and it is taken up from the apoplasm unaltered. Estimated sucrose concentrations within the apparent free space of Vicia and Phaseolus cotyledons were 105 and 113 mM respectively. Rates of in-vitro uptake of [¹⁴C]sucrose by cotyledon segments or by whole cotyledons following physical removal or porter inactivation of the outer cells demonstrated that, for both Vicia and Phaseolus cotyledons, the dermal cell complexes are the most intense sites of sucrose uptake. Accumulation of [¹⁴C]sucrose in the storage parenchyma of whole cotyledons was directly affected by experimental manipulation of uptake by the outer cell layers and plasmolytic disruption of the interconnecting plasmodesmata. These findings indicated that sucrose accumulated by the dermal cell complexes is transported symplasmically to the storage parenchyma. Overall, it is concluded that the dermal cell complexes of the developing legume embryo, irrespective of the presence or absence of wall ingrowths, are the major sites for the uptake of sucrose released from the maternal tissues to the seed apoplasm. Thereafter, the accumulated sucrose is transported radially inward through the symplast to the storage parenchyma.Abbreviations AFS apparent free space - CF 5-(6)-carboxyfluorescein - CFDA 5-(6)-carboxyfluorescein diacetate - Mes 2-(N-morpholino)ethanesulfonic acid - PCMBS p-chloromercuribenzenesulfonic acid - SRG sulphorhodamine G The investigation was supported by funds from the Research Management Committee, The University of Newcastle and the Australian Research Council. One of us, R. McDonald, gratefully acknowledges the support of an Australian Postgraduate Research Award. We are grateful to Stella Savoury for preparing the photomicrographs.     

Resistance of the group A streptococcal L form to sonic oscillation

The mechanical fragility of the L form of two group A streptococcal strains was assessed by subjecting L-form suspensions to sonic oscillation (60 W, 20 kc/sec). To evaluate the effect of the sonic energy applied, the original streptococcal strains and aSerratia marcescens strain were subjected to the same treatment. The killing of the organisms by sonic oscillation followed the expression log N_o/N_t=–K·t^1/2. The mortality rate constants K of the streptococcus,S. marcescens and the L form of the AED and GL-8 streptococcal strains were –0.19,–0.98,–1.14 and–1.52 min^–1/2. respectively. The mortality rates of the L form of the two streptococcal strains differed significantly (P=0.01). From a comparison of these data, and taking into account the difference in cell envelope between the bacterial and the L form, it is concluded that the limiting envelopes of the group A streptococcal L-form elements probably possess a relatively marked stability. The factors which might be responsible for the difference in mortality rates between the L form of the streptococcal strains are discussed.The author wishes to thank Dr. W. Hijmans (Institute for Rheumatism Research, Leiden) for his contribution to and constant interest in the work and Mr. J. C. Houwelingen (Department of Mathematical Statistics, Utrecht) for the statistical analysis. This study could not have been accomplished without the able and conscientious technical assistance of Miss H. L. Ensering (Institute for Rheumatism Research, Leiden), which is gratefully acknowledged.     

Resolution of two molecular forms of sucrose-phosphate synthase from maize,soybean and spinach leaves

Two forms of sucrose-phosphate synthase (EC 2.4.1.14) were resolved from leaves of three species, maize (Zea mays L. cv. Pioneer 3184), soybean (Glycine max (L.) Merr., cv. Ransom) and spinach (Spinacia oleracea L. cv. Resistoflay) by hydroxyapatite Ultrogel chromatography, using a 75-mM (designated peak 1) and 250-mM (peak 2) K-phosphate discontinuous-gradient elution. Rechromatography of the two forms showed that they were not readily interconvertible. The distribution of activity between the two forms differed among species and changed during purification of the enzyme. Recovery of peak-1 activity was specifically lowered when maize leaf extracts were prepared in the absence of magnesium, indicating that the two forms may differ in stability. In addition, the forms of the enzyme from maize differed in the extent of glucose-6-phosphate activation. These results provide evidence for the existence of multiple forms of sucrose-phosphate synthase in leaves of different species and that the forms differ in regulatory properties.Abbreviations Fru6P fructose 6-phosphate - Glc6P glucose 6-phosphate - HAU hydroxyapatite Ultrogel - Pi inorganic phosphate - SPS sucrose-phosphate synthase - UDP uridine 5-diphosphate - UDPG uridinediphosphate glucose Cooperative investigations of the United States Department of Agriculture, Agricultural Research Service, and the North Carolina Agricultural Research Service, Raleigh. Paper No. 10511 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh. Supported in part by USDA Competitive Research Grant No. 85-CRCR-1-1568     

A computer-assisted examination of the storage protein genetic variation in 841 accessions of Triticum dicoccoides

Summary Triticum turgidum L. var. dicoccoides (wild emmer) is an important genetic resource for increasing the protein content of common wheat (Triticum aestivum L.). Many studies have shown that the presence or absence of bands in sodium dodecyl sulfate polyacrylamide (SDS-PAGE) electrophoregrams of wheat storage proteins to be of a purely genetic character. A total protein extraction and SDS-PAGE technique was used to estimate the storage protein genetic variability among 841 accessions of wild emmer collected from various ecological regions in the Middle East. In addition, a computer data bank was developed, recording the onedimension electrophoregram bands for each accession by molecular weight (MW) and relative Coomassie Blue staining intensity as determined from densitometer scans. Analyses of this information are being used to identify specific accessions for further study by two dimension electrofocusing-electrophoresis and breeding and genetic analyses. The computer-assisted analyses indicated that the greatest genetic variability occurs for proteins in the high MW region (above 70,000 MW) followed by those in the medium range (70,000 to 33,300 MW). Comparatively little variability was revealed for protein subunits of below 33,300 MW.Scientific Paper No. 6591. College of Agriculture Research Center, Washington State University, Pullman, Project No. 1568. This work was supported in part by the U.S.-Israel Binational Agricultural Research and Development Fund (BARD)     

The heart Ultrastructure of lepidopleurus asellus (Spengler) and Tonicella marmorea (Fabricius) (Mollusca: Polyplacophora)

Summary The ultrastructure of the auricles, the ostia, and the ventricle of L. asellus and T. marmorea is described. The heart wall consists of an epicardium, a basement membrane, and an inner loose myocardium. The epicardial cells of the auricle are podocytes. The exposed cell body and the branched processes show pedicles. Ventricular epicardium is flat and simple. The slender, unbranched, mononucleated muscle fibres have a peripheral nucleus located midway along the fibre. Mitochondria are peripherally located, leaving the center to longitudinally running thick and thin myofilaments. Dense bodies and attachment plaques make up the Z-material. Sarcomeres and myofibrils are absent, as are transverse tubules and intercalated disks. The sarcoplasmic reticulum consists of peripheral tubules and subsarcolemmal cisternae, some of which radiate, branch, and run between myofilaments. Couplings are lacking. Ventricular fibres in T. marmorea show nexuses and desmosomes; in L. asellus only nexuses. The muscular ostia are tubular, and muscle fibres resemble those of the ventricle; nexuses are detected in T. marmorea and desmosomes in L. asellus. The only nervous elements observed are some nerve processes, structurally similar to those of other molluscs.Supported by grants from the Norwegian Research Council for Science and Humanities     

Interspecific hybrids between kenaf ( Hibiscus cannabinus ) and roselle ( H. sabdariffa )

The successful interspecific cross is reported for the first time between kenaf (Hibiscus cannabinus L.), a diploid species (2n=36) and roselle (Hibiscus sabdariffa L.), a tetraploid species (2n=72). Kenaf, grown for its bast fiber and also under investigation as a source of paper pulp, is fast-growing and well adapted to mechanical harvesting, but susceptible to root-knot nematodes. Roselle, also grown for its bast fiber, is slower growing, not well adapted to mechanical harvesting, but certain varieties are resistant to root-knot nematodes. Five hybrid plants were produced from the pollination of 4,445 flowers of kenaf with pollen from roselle; no hybrid plants were produced from 2,655 pollinations made in the reciprocal direction. One line of roselle was the parent of 3 of the 5 hybrids; one line of kenaf was the parent of 2 of these 3. The F₁ hybrids were triploid, and varied in vigor, growth habit and vegetative morphology, but had similar flowers. Two of the F₁ hybrids showed high pollen fertility, apparently as a result of restitution at first meiotic division leading to unreduced spores. These two hybrids each produced a small amount of seed, which gave rise to an F₂ population of 22 plants. The F₂ plants vary in vigor but are morphologically uniform, have thick leaves with mosaic sectors, and are presumably spontaneous allohexaploids. The theoretical possibilities of increasing the percentage of recovery of the F₁ interspecific hybrids and of developing a synthesized hybrid variety useful for bast fiber and paper pulp are discussed. Research done cooperatively by Crops Research Division and Agricultural Engineering Research Division, Agricultural Research Service, U.S. Department of Agriculture (USDA), and the University of Florida Agricultural Experiment Station. Cytological investigations were carried out at the Department of Biological Sciences, Florida State University. Thanks are extended to the many individuals and organizations who supplied material for this study, and to M. Griffin Bell and E. Otho Richey, Agricultural Research Technicians, for their enthusiastic assistance.     

Expression of enzymatically active and correctly targeted strictosidine synthase in transgenic tobacco plants

Strictosidine, a precursor to over 1000 indole alkaloids including the anti-tumor drugs vinblastine, vincristine, and camptothecin, is produced by the condensation of tryptamine and secologanin. Strictosidine synthase, the enzyme responsible for this condensation, is the first committed step in the indole-alkaloid pathway. We have introduced a modified cDNA encoding Strictosidine synthase from Catharanthus roseus (L.) Don. (McKnight et al. 1990, Nucl. Acids Res. 18, 4939) driven by the CaMV 35S promoter into tobacco (Nicotiana tabacum L.). Transgenic tobacco plants expressing this construct had from 3 to 22 times greater strictosidinesynthase activity than C. roseus plants. Ultrastructural immunolocalization demonstrated that strictosidine synthase is a vacuolar protein in C. roseus and is correctly targeted to the vacuole in transgenic tobacco. Immunoblot analysis of strictosidine synthase showed that two distinct forms of the enzyme were produced in transgenic tobacco plants but that only a single form was made in C. roseus. This observation indicates that the second form of the protein is not simply a result of overexpression in tobacco, but may reflect differences in protein processing between tobacco and C. roseus.Abbreviations cDNA complementary DNA - TLC thin-layer chromatography We thank Dr. C.A. Roessner for providing the E. coli strain expressing strictosidine synthase, Dr. J. Balsevich for providing alkaloid standards, and Dr. L. Cloney for assisting with antibody preparation. This work was supported by a National Institutes of Health Biomedical Research Support Grant to T.D.M and by a grant from the US Department of Agriculture, Competitive Research Grants Office (90-37262-5375) to C.L.N.