Temperature and salinity effect on growth and chemical composition of Gyrodinium aureolum Hulburt in culture

A factorial experiment shows highly significant effects of temperature(12 5–22.5°C) and salinity (17.8–34 S) on thegrowth rate of Gyrodinium aureolum, with a significant temperature-salinityinteraction. The maximum growth rate of G aureolum is measuredto 0.61 div. day^–1 at 20°C and 22.3 S. Gyrodiniumaureolum does not grow at temperatures :10 °C or 25°Cand at salinities 12 S. The cellular content of carbon (C) andnitrogen (N) and the elemental ratios N/C, P/C and N/P are significantlyaffected by the temperature The cellular content of phosphorus(P) and the elemental ratios P/C and N/P vary significantlywith salinity Significant temperature-salinity interactionsare found for the cellular content of carbon, nitrogen and phosphorus.Variations in the N/P ratio indicate that G.aureolum has a largestorage capacity for phosphorus It is suggested that temperatureis one important limiting factor in the initiation of bloomsof G.aureolum in north European waters.     

Acid Phosphatase Activity in Karri (Eucalyptus diversicolor F. Muell.) in Relation to Soil Phosphate and Nitrogen Supply

O'Connell, A. M. and Grove, T. S. 1985. Acid phosphatase activityin karri (Eucalyptus diversicolor F. Muell.) in relation tosoil phosphate and nitrogen supply.—J. exp. Bot. 36: 1359–1372 Soluble acid phosphatase activity was measured in tissues ofkarri (Eucalyptus diversicolor F. Muell.) seedlings and fiveyear old karri trees to which P and N fertilizer had been applied.Addition of P from 0 to 1250 mg P kg^–1 soil with a basaltreatment of other nutrients produced significant increasesin growth, P content and P concentration of karri seedlings.In each of five plant components (shoot tips, partly expandedleaves, mature leaves, young stems and old stems) soluble acidphosphatase activity was greatest at low levels of added P anddecreased with increasing soil P supply. The range of acid phosphataseactivity (0·5-6·5 µmol NPP g^–1 f.wt.min^–1) was similar to that reported for a number of agriculturaland horticultural plants. Enzyme activity was highest for shoottips and lowest for old stems. However, the relative changein activity with decreasing soil P supply was greatest for stems(4·3 fold) and least for shoot tips (2·7 fold) Mature leaves of seedlings grown in ‘high P’ and‘low P’ soil at four levels of added N showed, inaddition to the effect of P, a significant N-P interaction onsoluble acid phosphatase activity. In leaf samples from fiveyear old karri trees there was a significant decrease in solubleacid phosphatase with increasing P fertilization. Addition ofN fertilizer had no significant effect on enzyme activity, probablybecause added N had little effect on foliar N concentrations Exponential models relating (1) plant growth to enzyme activityand (2) plant growth to P concentration in stems and matureleaves of plants grown in soil with a range of added P accountedfor 78–92% and 63–87%, respectively, of the variationin top dry weight. The results suggest that for the diagnosisof plant P status, (1) stem components may be the most appropriatetissue to sample, and (2) nutrient and enzyme assays may complementeach other, P concentration being most useful where P supplyis adequate and phosphatase activity where P supply limits growth Key words: Phosphatase activity, Eucalyptus diversicolor, nutrients, phosphorus, nitrogen, forests     

Biochemical compositions of two dominant bloom- forming species isolated from the Yangtze River Estuary in response to different nutrient conditions

Variations of cellular total lipid, total carbohydrate and total protein content of two dominant bloom-forming species (Skeletonema costatum and Prorocentrum donghaiense) isolated from the Yangtze River Estuary were examined under six different nutrient conditions in batch cultures. Daily samples were collected to estimate the cell growth, nutrient concentration and three biochemical compositions content during 7 days for S. costatum and the same sampling procedure was done every other day during 10 days for P. donghaiense. Results showed that for S. costatum, cellular total lipid content increased under phosphorus (P) limitation, but not for nitrogen (N) limitation; cellular carbohydrate were accumulated under both N and P limitation; cellular total protein content of low nutrient concentration treatments were significantly lower than that of high nutrient concentration treatments. For P. donghaiense, both cellular total lipid content and total carbohydrate content were greatly elevated as a result of N and P exhaustion, but cellular total protein content had no significant changes under nutrient limitation. In addition, the capability of accumulation of three biochemical constituents of P. donghaiense was much stronger than that of S. costatum. Pearson correlation showed that for both species, the biochemical composition of three constituents (lipid, carbohydrate and protein) had no significant relationship with extracellular N concentration, but had positive correlation with extracellular and intracellular P concentration. The capability of two species to accumulate cellular total lipid and carbohydrate under nutrient limitation may help them accommodate the fluctuating nutrient condition of the Yangtze River Estuary. The different responses of two species of cellular biochemical compositions content under different nutrient conditions may provide some evidence to explain the temporal characteristic of blooms caused by two species in the Yangtze River Estuary.     

Pumpkin (Cucurbita sp.) seed globulin VI. Proteolytic activities appearing in germinating cotyledons

N--benzoyl D,L-arginine p-nitroanilide (BAPA), leucine p-nitroanilide(LPA) and casein hydrolytic activities were assayed in germinatingcotyledons. BAPA hydrolytic activity was not detected in dryseeds, but increased rapidly from 1 to 4 days of germinationand then decreased. LPA and casein hydrolytic activities weredetected in dry seeds and increased from 2 to 4 days. Caseinhydrolytic activity decreased faster than the other two activities. BAPA hydrolytic enzyme was partially purified. It was inhibitedby p-chloromercuribenzoate and activated by ß-mercaptoethanoland dithiothreitol, but was not affected by EDTA, phenylmethylsulfonylfluoride, pumpkin trypsin inhibitor and several divalent cations.It had no ability to hydrolyze globulin or the chain to produce F_ß or smaller polypeptides,respectively, which was referred to as proteolytic activityI in the preceding paper (14), but released small peptides andamino acids from the chain and F_ß. However, it wasdifferent from proteolytic enzyme II which was present in dryseeds and inhibited by EDTA (14). Pumpkin trypsin inhibitor was purified. Its molecular weightwas estimated to be 10,500 by gel filtration. It did not inhibitthe BAPA hydrolytic enzyme. Both proteolytic activities I andII were also not reduced by the inhibitor (14). The inhibitoryactivity decreased gradually during germination. (Received November 9, 1979; )     

Changes in the Activities of Various Glycosidases during Carrot Cell Elongation in a 2,4-D-Free Medium

Changes in the activities of some glycosidases were studiedin carrot suspension cultures with and without 2,4-D. Remarkablecell elongation occurs in a medium without 2,4-D, while fewcells elongate in a medium containing it. Glycosidases werefractionated into soluble, ionically wall-bound, tightly wall-boundand extracellular enzymes. The optimum pHs of all the ionicallybound glycosidases were in an acidic range, 4.4–5.0. The activities of the ionically and tightly bound ß-xylosidasesand ß-galactosidases were higher in elongating thanin non-elongating cells. Furthermore, the activities of theseenzymes increased with cell elongation during culture, suggestingthat they may play important roles in cell elongation. Higheractivities of soluble and cell wall-bound ß-glucosidaseand -mannosidase were found in non-elongating rather than inelongating cells. The activities of all soluble glycosidasesexcept ß-xylosidase were also higher in non-elongatingcells. Only ß-xylosidase and ß-galactosidaseactivities were detectable in the medium of the elongation culture. ¹ Present address: Department of Agricultural Chemistry, ObihiroUniversity of Agriculture and Veterinary Medicine, Obihiro,Hokkaido 080, Japan.     

Do the polyunsaturated aldehydes produced by Phaeocystis pouchetii (Hariot) Lagerheim influence diatom growth during the spring bloom in Northern Norway?

The marine bloom-forming phytoplankter Phaeocystis pouchetii(Prymnesiophyceae) is known to produce and release the cytotoxic,ß,,-unsaturated aldehyde 2-trans-4-trans-decadienal(DD), known to inhibit mitotic cell divisions in several differentcell types. The possible allelopathic effects of DD on monoculturesof three common diatoms from the coastal waters of northernNorway were assessed. The results showed that division ratesfor all three diatom species (Skeletonema costatum, Chaetocerossocialis and Thalassiosira antarctica) decreased as concentrationof DD increased. Furthermore field data from the spring bloomin Vestfjorden (2000 and 2001) were analysed to examine whetherthe presence of P. pouchetii influences other species adversely.Our data revealed no significant adverse effect of P. pouchetiion diatom presence since diatom diversity generally was positivelycorrelated to P. pouchetii biomass. The year with the lowestamounts of P. pouchetii had the lowest diversities, and thediatom species composition and abundance was comparable to situationswhere P. pouchetii was either absent or present in minute amounts.At some instances low diversity co-occurred with large fractionsof P. pouchetii, but since this were at the strongest verticalmixing we believe this to be a result of physical control. P.pouchetii and S. costatum were the most frequently co-occurringspecies, and since they are both known producers of polyunsaturatedaldehydes we cannot exclude the possibility that the presenceof DD released from P. pouchetii induced by heavy grazing mightinfluence the growth of other phytoplankton species.     

Characterization of Common Carbohydrate Antigenic Determinants on Soya Bean Cell-Wall Enzymes

Three soya-bean (Glycine max) cell-wall enzymes (ß-glucosidase,pectin methyl esterase and phosphatase) have been found to beglycoproteins. The polyclonal antibodies raised against pectinmethyl esterase and ß-glucosidase lacked specificity,cross-reacted highly with native enzymes and also both reactedwith pure soya-bean phosphatase, horseradish peroxidase andhoneybee venom phospholipase A2. They did not react with eithernon-glycosylated bacterial phosphatase or deglycosylated cell-wallenzymes. The two antisera contained both non-specific anti-glycanantibodies and specific anti-polypeptide antibodies that werequantified. Antiglycan antibodies specific to 1–3 fucoseand ß1–2 xylose were detected in both antiseraand were separated and quantified. The occurrence of terminalfucose (and mannose) was confirmed with specific lectins. Theseresults indicate that most of the common glycan epitopes probablycorrespond to the asparagine-linked complex glycan previouslydetected in several glycoproteins of plants as well as in thoseof molluscs and insects. (Received March 10, 1993; Accepted November 5, 1993)     

Maternal Effects of mto1 Mutation, That Causes Overaccumulation of Soluble Methionine, on the Expression of a Soybean {beta}Conglycinin Gene Promoter-GUS Fusion in Transgenic Arabidopsis thaliana

ß-Conglycinin, the 7S seed storage protein of soybean(Glycine max [L.] Merr.), is comprised mainly of three subunits,designated , ' and ß. Expression of the gene encodingthe ß subunit is unique because its expression hasbeen shown to be down-regulated by exogenously applied L-methioninein immature soybean cotyledon cultures in vitro. Arabidopsisthaliana strain carrying a mto1-1 mutation overaccumulates solublemethionine. By using this mutant, we analyzed the effects ofmethionine on expression of the ß subunit gene invivo. Reciprocal crosses were made between the mto1-1 mutantand a transgenic A. thaliana strain, designated SNTß3,which carries a ß-glucuronidase (GUS) reporter geneunder the control of the promoter region of the ßsubunit gene. Analysis of GUS activity in F₁ seeds indicatedthat the GUS activity was dramatically repressed when the mto1-1mutant plants were used as female parents. We constructed astrain which carries both the transgene and mto1-1 mutationin the homozygous state. Analyses of the GUS activity in seedsof this double homozygous strain indicated that the GUS activitywas repressed to 2.5% of control by introduction of the mto1-1mutation. These results indicate that the ß subunitgene promoter activity in seeds is down-regulated by maternalgenotype and suggest that soluble methionine, or its mobilemetabolite, is translocated from mother plants to repress ßsubunit gene expression in seeds. ⁵Present address: Division of Biological Sciences, GraduateSchool of Science, Hokkaido University, Kita-ku, Sapporo, 060Japan ⁶Present address: Department of Biotechnology, Faculty of Agriculture,The University of Tokyo, Bunkyo-ku, Tokyo, 113 Japan     

Distribution of Glycosidases and Acid Invertase Activities in Relation to Elongation Growth in Pearl Millet Internode

The mean cell length along a differentiating internode and alliedchanges in the activities of ß-glucosidase, - andß-galactosidase. -mannosidase and acid invertase,together with the contents of reducing and non-reducing sugars,were examined in pearl millet (Pennisetum americanum L. Leekecv. BJ-104). The specific activities of cytoplasmic -mannosidase,wall ß-glucosidase, and cytoplasmic and wall acidinvertase showed close relationships with the rate of cell elongation.The linear regressions of the rate of cell elongation, and thespecific activities of wall ß-glucosidase and cytoplasmicand wall invertase showed significant positive correlations(P<0·05), whereas cytoplasmic -mannosidase was negativelycorrelated (P<0·01). The results are discussed in the light of cell wall looseningand the provision of carbon substrates for cell elongation. Key words: Glycosidases, acid invertase, sugars, cell elongation, Pennisetum americanum L., Leeke     

Levels of {beta}-Glucan and Lignin in Elongating Internodes of Deepwater Rice

Partial submergence or treatment with either ethylene or gibberellicacid (GA₃ induces rapid growth in deepwater rice (Oryza sativaL.). We correlated the synthesis of two cell wall componentswith two phases of internodal elongation, namely (13,14)-ß-glucanformation with cell elongation and lignification with differentiationof the secondary cell wall and cessation of growth. The contentof ß-glucan was highest in the zone of cell elongationin internodes of air-grown plants and plants that were inducedto grow rapidly by submergence. In the intercalary meristemand in the differentiation zone of the internode, ß-glucanlevels were ca. 70% lower than in the zone of cell elongation.The outer cell layers, enriched in epidermis, contained moreß-glucan in submerged, rapidly growing internodesthan in air-grown, control internodes. The ß-glucancontent of the inner, parenchymal tissue was unaffected or slightlylowered by submergence. The epidermis appears to be the growth-limitingstructure of rapidly growing rice internodes. We hypothesizethat elevated levels of ß-glucan contribute to elongationgrowth by increasing the extensibility of the cell wall. Lignificationwas monitored by measuring the content of lignin and the activitiesof two enzymes of the lignin biosynthetic pathway, coniferylalcohol dehydrogenase (CAD) and phenylalanine ammonia-lyase(PAL), in growing and non-growing regions of the internode.Using submerged whole plants and GA₃-treated excised stem segments,we showed that lignin content and CAD activity were up to sixfoldlower in newly formed internodal tissue of rapidly growing ricethan in slowly growing tissue. No differences were observedin parts of the internode that had been formed prior to inductionof growth. PAL activity was reduced throughout the internodeof submerged plants. We conclude that lignification is one ofthe processes that is suppressed to permit rapid growth. ¹ This work was supported by the National Science Foundationthrough grants No. DCB-8718873 and DCB-9103747 and by the Departmentof Energy through grant No. DE-FGO2-90ER20021. M.S. was therecipient of a fellowship from the Max Kade Foundation.     

Functional Significance of Acid Phosphatase Distribution During Embryo Development in Pisum sativum L

The distribution of P₁, ester P and acid-insoluble nucleic acidP has been studied in relation to acid phosphatase activity(EC 3. 1. 3. 2) in the component parts of developing pea seeds(Pisum sativum L.). Despite the favourable pH of the liquidcontents of the embryo sac (pH 5.5), only very low acid phosphataseactivity was detected in this fluid (c. 0.01 units per seed).Potential substrates for phosphatase action were in fact absentfrom the secretion, the only form of P present being P_i, inconcentrations up to 8 mM. The data support the hypothesis thatthe high acid phosphatase activities which develop in the seed-coatsare involved in regulating the supply of P as P₁ to the developingembryo. Pisum sativum L., pea, embryo development, acid phosphatase, phosphorus, seed-coats, seed development     

Function of Lysosomes and Lysosomal Enzymes in the Senescing Corolla of the Morning Glory (Ipomoea purpurea)

The rapid senescence of the Ipomoea corolla is characterizedby the breakdown of protein and nucleic acids. At the onsetof wilting the activities of deoxyribonuclease (DNase), ribonuclease(RNase), and ß-glucosidase are increased dramatically,while other hydrolytic activities such as the actions of protease,aminopeptidase, -glucosidase, phosphatase, esterase, and -amylaseare only slightly changed. Isolated corolla discs show a course of senescence similar tothat of the intact organ. When floating on solutions of cycloheximidethe activities of DNase, RNase, and ß-glucosidasedo not increase. Actinomycin D inhibits the increase in RNaseactivity. It is concluded that protein synthesis is a prerequisitefor the changes in these enzyme activities in the senescingcorolla. The function of the lysosomal compartment in the process ofsenescence is illustrated by electron micrographs showing theautophagic activity of vacuoles. The last phase of senescenceis characterized by the breakdown of the tonoplast and completedigestion of the cytoplasmic constituents in the autolysingcells.     

Sugar Content and Metabolic Activities in Cold-Stored Fragmented Xylopodium of Ocimum nudicaule Benth. var. anisifolia Giul. (Labiatae)

Sugar content and hydrolytic activities were measured in fragmentsof xylopodia of Ocimum nudicaule Benth. stored for one weekat 5 °C and 5.28 °C. At 5 °C the soluble carbohydratecontent first decreased and at 5.28 °C it increased duringstorage and then declined drastically during cultivation afterplanting. Galactose, glucose and fructose levels also rose at5–28 °C whereas at 5 °C only glucose increased.These changes in sugar level were found to be correlated withchanges in the activity of certain hydrolytic enzymes: at 5–28°C there was a rapid rise in the activities of -galactosidaseand hemicellulase followed by an increase in the activity ofinvertase and ß-galactosidase. The rapid changes inenzymes and carbohydrate levels are discussed in terms of adaptationof the plant to tropical and subtropical environments. Key words: Carbohydrates, Carbohydrate hydrolases, Underground organ (xylopodium), Cold storage     

{beta}-Amylase Activity as an Index for Germination Potential in Rice

Seeds of different vigour also differ in their germination ability.In rice (Oryza sativa), this difference was correlated withthe level of incorporation of ³⁵S-methionine into 25-60% ammoniumsulphate precipitable material that was rich in amylase proteins.This protein fraction, from dry seeds, contained no -amylaseactivity. In contrast, ß-amylase activity was presentin all seed stocks capable of 99% germination, although thelevel was lower in seeds that grew slowly when germinated. Inlow viability low vigour stock (i.e. extensively deterioratedseeds) ß-amylase activity was absent. Alpha-amylaseactivity in all stocks was detected only after 24 h from thestart of imbibition. These results indicate that ß-amylaseactivity is reliable indicator of the germination ability ofrice seed stocks and of their vigour during germination.Copyright1995, 1999 Academic Press Rice (Oryza sativa L.,), germination, ß-amylase, -amylase, seed vigour     

Glycosidases from Cotyledons of Pisum sativum L.

-Mannosidase and ß-N-acetylglucosaminidase were purifiedfrom extracts of cotyledons of germinating Pisum sativum L.A 13-fold purification of a-mannosidase free from ß-N-acetylglucosaminidaseactivity was achieved by precipitation in ammonium sulphate,column chromatography on DEAE-cellulose, and treatment with2 M pyridine. ß-N-Acetylglucosaminidase was purified200-fold by the use of (NH₄)₂SO₄, and chromatography on ConcanavalinA¹-Sepharose and Sephacryl-200. This preparation showed no measurablecontamination by -mannosidase activity. Both glycosidases appearto be glycoproteins and demonstrate optimal activity at pH valuesof 4.0–4.5. Both glycosidases appear to have very similarmolecular weights, with -mannosidase being slightly larger thanß-N-acetylglucosaminidase. An extensive search forthe activity of aspartylglycosylamine amido hydrolase in peacotyledons proved unsuccessful.     

Intraspecific Variation in Oil Components ofBoronia megastigmaNees. (Rutaceae) Flowers

Intraspecific variation in the oil composition ofBoronia megastigmaNees.(Rutaceae) was examined. Boronia absolute is extracted fromblossom primarily for use as a food additive. A major componentis ß-ionone andB. megastigmais one of the commercial,natural sources of this compound. Genotypes superior in productionof ß-ionone and low in monoterpene hydrocarbons weresought from natural populations in the south west of WesternAustralia as part of a breeding programme. Flowers were collectedfrom 25 plants in each of 29 different populations. Blossomwas extracted with ethanol and analysed using a gas liquid chromatographfitted with ionisation detectors. The contents of ß-ionone,dodecyl acetate, -pinene, ß-pinene and limonene inthe oil extract were compared. Intra-population variation wasas great as inter-population variation and no distinct chemotypeswere found. Considerable variation existed in the content ofcomponents. The highest ß-ionone content was 1787mg g^-1f. wt. Some genotypes contained all five components analysed,others lacked one or more of the monoterpenes: -pinene, ß-pineneor limonene. Principle components analysis indicated that contentsof ß-ionone and dodecyl acetate were associated andthat they were distinct from the content of the monoterpenes,which were associated with each other. Natural shading was associatedwith lower levels of monoterpenes but other oils were unaffected.Young plants contained less pinenes than older plants and oldplants contained the most dodecyl acetate. Vigorous plants producedmore pinenes. Red flowers contained the least ß-iononeand dodecyl acetate.Copyright 1999 Annals of Botany Company Boronia megastigma,boronia, Rutaceae, oil, -pinene, ß-pinene, limonene, ß-ionone, dodecyl acetate, monoterpenes, chemotypes.     

Activity of Wall-bound Enzymes in Callus Cultures of Gossypium hirsutum L. During Growth

Activities of - and ß-glucosidase, - and ß-galactosidase,-mannosidase, ß-1,3-glucanase, acid and neutral invertaseswere detected in the cytoplasmic fraction as well as in cellwalls isolated from callus cultures of cotton. Activity of ß-mannosidase,however, could not be detected in the cell walls. Transfer ofcallus to a fresh medium did not immediately influence the activitiesof -glucosidase and ß-galactosidase but increasedsignificantly ß-glucosidase, -mannosidase, acid andneutral invertases. Addition of cycloheximide (1 and 100 mgl^–1) further stimulated acid and neutral invertases butnot other enzymes tested. Sodium chloride (NaCl) was effectivein extracting a-glucosidase, ß-glucosidase, ß-galactosidase,acid and neutral invertases. EDTA extracted most of the -galactosidase,-mannosidase, ß-1,3-glucanase and some -glucosidase.But, NaCl and EDTA could not extract some of the - and ß-glucosidasesand also acid and neutral invertases as evidenced from the residualand extra cellular activity. Studies with whole cells as a sourceof enzyme revealed that some of these enzymes were associatedwith the cell surface. Callus, glycosidases, glucanase, growth, Gossypium hirsutum     

Pumpkin (Cucurbita sp.) seed globulin V. Proteolytic activities involved in globulin degradation in ungerminated seeds

Two proteolytic activities I and II involved in the globulindegradation were detected in pumpkin seeds. Activity I, hydrolyzing and ß subunits of the globulin to form F_ß,was found in both dry seeds and cycloheximide-treated cotyledons,and decreased during germination. Activity II, hydrolyzing F_ßto produce small peptides and amino acids, was not observedin dry seeds but found in cycloheximide-treated cotyledons,increased up to 4 days, and gradually decreased during germination. Activity I gave limited hydrolytic products from the globulinand the chain, but not from F_ß, the chain and some animal proteins. It was inhibitedby EDTA. On the other hand, activity II hydrolyzed F_ßand the chain faster than the globulin, the chain and some animal proteins. It was inhibitedby EDTA and p-chloromer-curibenzoate, and activated by ß-mercaptoethanol,dithiothreitol and CoCl₂. Optimum pH's were at about 6.8 andat 6.0 to 6.8 for activities I and II, respectively. The degradation process of the globulin can be divided intotwo steps: the first step is the conversion of globulin to F_ßand the second step, F_ß to small peptides and aminoacids. (Received November 9, 1979; )     

Activity of Some Hydrolytic Enzymes in Autolysis of the Embryo Suspensor in Tropaeolum majus L.

Assay of amino-peptidase, acid and alkaline phosphatase, esteraseand ß-glucosidase activity in the haustoria and suspensorof Tropaeolum majus embryos at different stages of developmentis made to evaluate the function of hydrolases in autolysisof the suspensor. Enzyme activities rise to a maximum sometimebetween heart-shaped and cotyledonary phases of embryo development. Tropaeolum majus L. nasturtium, embryology, suspensor, autolysis, hydrolytic enzymes