bluuebunny/crossref_metadata_2025_split huggingface dataset:
PHYTOCHROME CONTROL OF NITRATE REDUCTASE ACTIVITY AND ANTHOCYANIN SYNTHESIS IN LIGHT‐GROWN SINAPIS ALBA (L.). DIFFERENTIAL RESPONSES OF COTYLEDONS AND HYPOCOTYLS
Authors: WHITELAM G. C. , JOHNSON C. B. 
Published: May 2006

SummaryIn 40 h old cotyledons of etiolated Sinapis alba (L.) red/far‐red photoreversibility and the effect of continuous far‐red light were used to demonstrate the involvement of phytochrome in the control of in vivo nitrate reductase activity and anthocyanin synthesis. Over a period of several days during the development of S. alba seedlings, in the light, in vivo nitrate reductase activity and anthocyanin synthesis were determined in the cotyledons and hypocotyls. Seedlings were grown under two light environments; fluorescent white light, establishing an estimated phytochrome photo‐equilibrium, φE, of 0.69, simulating direct sunlight and fluorescent white light with added far‐red light, establishing an estimated phytochrome photo‐equilibrium of 0.26, simulating ‘shade’ or ‘canopy’ light. The time courses of both responses were greatly influenced by these different light qualities. Furthermore, in the case of nitrate reductase activity the cotyledons and hypocotyls showed marked differences in their responses to light quality. In the cotyledons a light source establishing a low photo‐equilibrium was initially more effective in eliciting the response, but with time, a light source establishing a high photo‐equilibrium became the more effective. In the hypocotyls a light source establishing a high photo‐equilibrium was always the more effective. The anthocyanin response showed the crossing over of effectiveness of high and low photo‐equilibrium in both tissues. The results are discussed in terms of the transition from the ‘high irradiance reaction’ of young seedlings to a possible steady state of phytochrome control in the mature plant.
THE RHIZOBIUM REQUIREMENTS OF THE NON‐LEGUME PARASPONIA IN RELATIONSHIP TO THE CROSS‐INOCULATION GROUP CONCEPT OF LEGUMES
Authors: TRINICK M. J. , GALBRAITH J. 
Published: May 2006

Summary Parasponia andersonii was nodulated by thirty four of thirty nine slow‐growing rhizobia isolated from tropical legumes and by R. japonicum and JR. lupini. The nitrogenase activity of nodulated plants within a rhizobial treatment varied widely. Effective associations were obtained with some but not all isolates from Cajanus cajan, Centrosema pubescens, Crotalaria anagyroides, Flemingia congesta, Inocarpus fragiferum, Macroptilium lathyroides, Phaseolus calcaratus, Stizolobium deeringianum and Stylosanthes gracilis. Little or no nitrogen was fixed with rhizobia from Albizia stipulata, Cassia mimosoides, Desmodium microphyllum, Pterocarpus indicus, Uraria lagopoides, and the wide‐host range cowpea Rhizobium strain CB 756. Fast‐growing rhizobia from Leucaena leucocephala, Mimosa invisa, M. pudica, Sesbania grandiflora and Lablab pur‐pur eus nodulated Parasponia with a low level of nitrogen fixation.Isolates from Parasponia failed to nodulate most of the legumes usually nodulated by slow‐growing rhizobia and when tropical legumes were nodulated, the association was either partially effective or ineffective; only isolate CP 283 was highly effective and promiscuous. Hosts normally nodulated with fast‐growing rhizobia, including Leucaena and Mimosa were not nodulated with isolates from Parasponia.It was concluded that the Parasponia‐Rhizobium symbiosis is best located in the ‘cowpea miscellany’.
PHOTOSYNTHESIS OF YOUNG ORCHID SEEDLINGS
Authors: HEW C. S. , KHOO S. I. 
Published: May 2006

SummaryAdult leaves, protocorms and seedlings of succulent tropical orchids exhibit diurnal fluctuations in acidity. The titratable acidity varied at different stages of growth. The fluctuation in acidity was barely detectable in protocorms but as they grew older, their capacity for acid accumulation increased.The O2 exchange in orchid protocorms and seedlings was similar to that of adult leaves in their responses to temperature, bicarbonate and light intensity. It is concluded that protocorms and seedlings resemble adult organs in having the characteristics of crassulacean acid metabolism (CAM).
STEROIDAL OESTROGENS AND PLANT GROWTH AND DEVELOPMENT
Authors: HEWITT S. , HILLMAN J. R. , KNIGHTS B. A. 
Published: May 2006

I. SUMMARYThe current information regarding the occurrence of steroidal oestrogens and the physiological significance of these compounds in plants is reviewed. Special reference is made to the effects of oestrogens on elongation growth, and results are presented from experiments with Pisum and Phaseolus seedlings.
THE EFFECT OF BENTAZONE ON STOMATAL BEHAVIOUR IN CHENOPODIUM ALBUM L.
Authors: TAYLOR F. ELIZABETH , COBB A. H. , DAVIES L. G. 
Published: May 2006

SUMMARYThe herbicide bentazone induces stomatal opening in epidermal strips of C. album in a light‐dependent response, over a temperature range of 9 to 29 °C. The relevance of these findings is discussed in relation to stomatal structure and the foliar penetration of the herbicide.
MYCORRHIZAE AND NUTRIENT CYCLING IN NATURAL FOREST ECOSYSTEMS
Authors: FOGEL ROBERT 
Published: May 2006

SUMMARYThe widespread occurrence of mycorrhizae in nature and their importance in the mineral nutrition of almost all plants has been extensively documented but despite this mycorrhizae have not been included in nutrient cycling studies of forest ecosystems. This neglect may be due to a failure on the part of researchers to recognize the functional differences between mycorrhizae and roots and to the labour‐intensive effort needed to study mycorrhizae.Biomass or surface area of mycorrhizae must be measured before information on ion absorption by mycorrhizae can be applied to forest ecosystems. A full assessment of the importance of mycorrhizae in nutrient cycling also requires data on mycorrhiza production, senescence, and decomposition. Few mycorrhiza studies have provided such data. Consequently, our information on nutrient cycling is derived from fine root (≥ 5 mm in diameter) data which may or may not include mycorrhizae.Recent studies have shown that most of the organic input to the decomposition process results from fine root production. Fine root mortality and decomposition is also more important than other mechanisms for returning nitrogen immobilized in vegetation to the soil in both deciduous and coniferous forests. A recently completed study indicates that mycorrhizae account for 50% of the annual throughput of biomass and for 43% of the nitrogen released annually in a Douglas fir ecosystem. These transfers are five times larger than the releases from litterfall or litter decomposition. Clearly, the study of mycorrhizal nutrient cycling is in an embryonic state and considerable additional research is needed.
SHORT‐ AND LONG‐DISTANCE TRANSPORT OF BORIC ACID IN PLANTS
Authors: RAVEN J. A. 
Published: May 2006

SUMMARYThe molecular weight and ether‐water partition coefficient of boric acid are consistent with a PB(OH)3 in plant cell membranes of at least 10‐6 cm s‐1. This permeability coefficient is high enough to account for the measured magnitude of boric acid fluxes at many plant cell membranes. The use of active transport of boric acid to maintain B distribution across a membrane away from thermodynamic equilibrium is consequently likely to be energetically expensive. The content of m‐diols (with which boric acid can form complexes) in cell walls and inside the cells varies widely between different plant species without any obvious correlation with either total B content or with the B content at which deficiency (in B‐requirers) or toxicity symptoms are manifested. B distribution at the cell level depends on the relative extents of passive permeation, active transport and cisdiol formation; regulations may be in response to total intracellular B rather than free boric acid.The net uptake of boric acid by intact vascular land plants is influenced by the rate of transpiration; while transport of B within the xylem is probably directly proportional to the rate of transpiration, neither whole plant B uptake nor transfer from root tissue into the xylem exhibit such a simple relationship. Redistribution of B in the phloem from transpirational termini is very limited. This limitation could result from the toxicity of B (which requires a low B concentration in the translocation stream relative to other nutrients and to sink requirements) or to ‘counter‐current distribution’ of B from the phloem to the adjacent xylem stream (low in B) through the B‐permeable sieve‐tube plasmalemma.The transport of B is discussed in relation to the evolution of multi‐cellular algae and of vascular land plants.
EFFECTS OF ORGAN EXCISION AND HORMONE APPLICATIONS ON LATERAL SHOOT EXTENSION AND INFLORESCENCE DEVELOPMENT IN CHRYSANTHEMUM MORIFOLIUM RAMAT
Authors: MENHENETT ROGER 
Published: May 2006

SUMMARYThe excision of young inflorescence (flower) buds and young, expanding leaves from lateral shoots of pot‐grown Chrysanthemum morifolium Ramat markedly reduced internode extension. The absence of flower buds in particular restricted growth in length. The removal of more mature leaves on lateral stems had little effect. Defoliation of the main stem did not influence lateral stem length but it did delay flowering.The application of gibberellic acid (GA) more than compensated for the removal of the flower bud and/or young leaves and promoted the elongation of intact shoots. It also increased the rate of flower bud development. While indol‐3‐ylacetic acid (IAA) promoted internode extension in shoots from which flower buds and young leaves had been excised, it never significantly altered the length of intact stems and tended to delay flowering. The cytokinin 6‐benzyladenine (BAP) supplied alone induced little response. Combinations of GA and IAA, or GA and BAP, decreased internode length compared to GA alone.The data suggest that of the organs of the shoot, the flower buds and young leaves are sites of production of the hormones necessary for stem elongation and that gibberellins play the major role in promoting this process.
THE EFFECTIVENESS OF VESICULAR‐ARBUSCULAR MYCORRHIZAS IN INCREASING GROWTH AND PHOSPHORUS UPTAKE OF SUBTERRANEAN CLOVER FROM PHOSPHORUS SOURCES OF DIFFERENT SOLUBILITIES
Authors: Pairunan A. K. , Robson A. D. , Abbott L. K. 
Published: May 2006

SUMMARYThe effect of inoculation, with a VA mycorrhizal fungus on growth and phosphorus uptake of subterranean clover was examined using three phosphorus sources with different solubilities. Mycorrhizas markedly increased growth and phosphorus content of tops at intermediate rates of phosphorus application for all sources.The effectiveness of phosphorus for plant growth for mycorrhizal plants relative to non‐mycorrhizal plants was the same for a water soluble source (superphosphate) and two insoluble sources (C‐grade Christmas Island rock phosphate and calcined Christmas Island rock phosphate). The effectiveness of phosphorus from each of the three sources for phosphorus uptake by mycorrhizal plants relative to non‐mycorrhizal plants was also independent of the solubilities of the phosphorus sources applied.At a given phosphorus concentration in tops, non‐mycorrhizal subterranean clover produced more dry matter than mycorrhizal clover supplied with superphosphate. Mycorrhizal and non‐mycorrhizal subterranean clover supplied with C grade rock phosphate had the same dry weight at a given phosphorus concentration in their tops.VA mycorrhizas increased zinc but not calcium uptake by subterranean clover.
EVOLUTION OF INCOMPATIBILITY SYSTEMS IN PLANTS: ORIGIN OF ‘INDEPENDENT’ AND ‘COMPLEMENTARY’ CONTROL OF INCOMPATIBILITY IN ANGIOSPERMS
Authors: Pandey K. K. 
Published: May 2006

SUMMARYIncompatibility is a common means of controlling breeding behaviour among plants, and has been an important factor in evolution. It acts to prevent self‐fertilization, as well as to prevent sterilization of ovules by foreign pollen. Angiosperms have both inter‐ and intraspecific incompatibility, and these are controlled by the same S gene complex. Gymnosperms, however, have only interspecific incompatibility. Observations on incompatibility behaviour in flowering plants have suggested that interspecific incompatibility evolved first among gymnosperms or progymnosperms as a means of protecting their naked ovules from foreign pollen. Duplication and redifferentiation of this ‘primary specificity’ gene in angiosperm precursors subsequently gave rise to ‘secondary specificity’ controlling intraspecific incompatibility.Today there are three basic types of incompatibility found among the angiosperms: (i) inherently independent control‐each allele independently expresses its individual specificity, shows allelic interaction in the pollen after S gene duplication; (ii) inherently complementary control‐alleles of two or more incompatibility loci co‐operate to produce a single specificity, shows no allelic interaction; and (iii) late complementary control‐alleles of two or more incompatibility loci co‐operate to produce a single specificity, shows allelic interaction. The pattern of distribution of these three types of control has given rise to a controversy over which represents the most primitive type of angiosperm incompatibility.The present paper examines the factors involved in secondary evolution of incompatibility, and concludes that independent control is in fact more primitive. Complementary control probably developed secondarily and independently several times during angiosperm evolution, the first occurrence, that of ‘inherently complementary’ apparently being among the progenitors of the monocotyledons. While the majority of dicotyledons have the original ‘inherently independent’ control, certain evolutionary lines appear to have switched independently to complementary control, the gametophytic system giving rise to ‘inherently complementary’ control and the sporophytic system giving rise to ‘late complementary’ control. A major factor in favour of complementary incompatibility system as opposed to independent control system is the advantage it confers in colonisation after long distance dispersal. The factors involved in the evolution of complementary control, together with certain genetic characteristics of this system, have probably played a significant role in the evolution and distribution of monocotyledons.
THE REPRODUCTIVE BIOLOGY OF ASCLEPIAS TUBEROSA: I. FLOWER NUMBER, ARRANGEMENT, AND FRUIT‐SET
Authors: WYATT ROBERT 
Published: May 2006

SUMMARYAn analysis of the inflorescence of the herbaceous perennial milkweed Asclepias tuberosa was carried out by sampling populations in North Carolina and Virginia in 1975 and 1976. Reproductive characters are strongly associated within a given level of comparison (e.g. stems per plant with flowers per plant) but show relative independence between levels (e.g. stems per plant with umbels per branch). Plant size is negatively correlated with fruit production on a proportional basis (fruit‐set) but positively related to the absolute numbers of fruits produced. The invocation of a ‘pollen donor strategy’ to explain the occurrence of large inflorescence displays in Asclepias is unnecessary, as these large plants have a larger female contribution to the next generation, irrespective of their male contribution. Self‐pollination is proposed as a process determining the upper limit of inflorescence size in Asclepias. Experimental pollinations suggest that early competition among ovaries within umbels is very important in determining levels of fruit‐set. Competition among ovaries in different umbels, time of pollination, and location of umbels also exert an effect. Inflorescence architecture likely represents a series of evolutionary compromises between maximization of pollinator attractiveness on the one hand and maximization of fruit maturation on the other.
THE EFFECT OF l‐ARGININE ON THE GROWTH OF HETEROTROPHIC CULTURES OF THE EMERSON STRAIN OF CHLORELLA. III. STUDIES WITH THE STRUCTURAL ANALOGUE CANAVANINE
Authors: Thinh L. V. , Griffiths D. J. 
Published: May 2006

SummaryThe special role of arginine in controlling cell division in heterotrophic cultures of Chlorella emersonii has been studied using the guanidoxy structural analogue, canavanine. Evidence is presented that competition between the two compounds probably occurs at the site of protein synthesis and that the analogue interferes with the synthesis of proteins essential for cell division and chloroplast development. An experimental system based on the light or dark recovery of previously heterotrophically grown cells has shown that protein synthesis which takes place after DNA replication is particularly sensitive to canavanine, and that the initial stages of recovery are important in countering the inhibitory effect of the analogue. The possibility is discussed that arginine‐proteins may have a general role in controlling cell division in Chlorella emersonii.
THE TEMPERATURE RANGE FOR FREEZING DAMAGE AND ITS RELATION TO HARDINESS
Authors: PEARCE R. S. 
Published: May 2006

SummarySeveral sets of data suggest that the range of temperatures over which damage or kill due to frost progressively increases (i.e. Δ°C/Δd, where d is % damage or % kill) is correlated with hardiness. The relationship may exist for several species of Gramineae, for alfalfa and for several types of tree and fruit bush. There appear to be exceptions to this generalization. A hypothetical explanation is offered.
ANTHOCYANIN VARIATION IN THE GENUS RUBUS
Authors: JENNINGS D. L. , CARMICHAEL ELEANOR 
Published: May 2006

summaryThe pigments of Rubus fruits vary in concentration and in the nature of the aglycones and sugars contained in the anthocyanin molecule. Variation in concentration is determined by the genes T, P, Y, Ys, Ycor and possibly Bl and by minor genes. Up to six sugars may be present: one monoglycoside, three diglycosides and two triglycosides. The monoglycoside was present in all the material studied and the presence or absence of the diglycosides rutinose, sophorose, and sambubiose was determined by segregation of the genes R, So and Xy. Synthesis of triglycosides occurred when genes So and R or Xy and R were present together. Cyanidin is the predominant aglycone of raspberries and blackberries, but pelargonidin occurred as traces in raspberries and as the predominant aglycone in R. parviflorus, a species of the sub‐genus Anoplobatus, and in R. pileatus, a species of the sub‐genus Idaeobatus. Knowledge of agenotype's anthocyanin sugars frequently provides evidence of its probable ancestry, but little evidence is available to suggest that any one sugar should be preferred to another.
ELECTROPHORETIC STUDIES OF CARPOPHORE DEVELOPMENT IN THE BASIDIOMYCETE COPRINUS CINEREUS
Authors: MOORE DAVID , JIRJIS RAIDA I. 
Published: May 2006

SUMMARYAcrylamide gel electrophoresis was used to resolve buffer‐soluble proteins and enzymes extracted from tissues of Coprimis cinereus. The electrophoretograms of proteins of two related but compatible monokaryons differed from one another, and both differed from the electrophoretogram of the dikarvon made by crossing the monokaryons together. The electrophoretogram of the youngest carpophore primordia was markedly different from that of the dikaryon on which they were produced, and the protein spectrum of both cap and stipe altered as the tissues matured. The protein electrophoretic pattern observed in the cap was always different from that of the stipe on which the cap was borne. However, when carpophores of quite different dikaryons were compared it was found that differences between the strains were so considerable that it was not possible to identify features common to a particular tissue or structure. Variation was also found in respect of isozyme patterns even though only two quite closely related monokaryons were compared.In the case of two enzyme activities (malate dehydrogenase and NADPH‐dehydrogenase) the monokaryons exhibited different numbers of isozymes, and in a further three (alcohol dehydrogenase, NADH‐dehydrogenase and esterase) there were clear differences in the way in which the isozyme pattern in each monokaryon related to the period of growth. The dikaryon was not associated with any predictable change in the isozyme pattern, but in all cases the dikaryon was in some way different from the parental monokaryons. Further differences were observed in carpophore tissues: in all cases the carpophore differed from its parental dikaryon. In most cases this difference was expressed as a distinctive developmental pattern of isozymes which were also detectable in mycelium; and in this the cap was often quite different from the stipe. However, for alcohol dehydrogenase and esterase, extracts of carpophore tissues possessed isozymes not detectable in extracts of mycelia.
THE DUAL POLYCLAVE: AN AID TO MORE EFFICIENT IDENTIFICATION
Authors: PAYNE R.W. , LAMACRAFT R. R. , WHITE R. P. 
Published: May 2006

SUMMARYPolyclaves have advantages over conventional aids to identification in that the user is free to examine any convenient character. However the polyclave gives no guidance about the best character to examine next during an identification. This deficiency can be overcome by using a dual polyclave which indicates how each character separates the taxa not eliminated by characters already observed.
PHYTOPHTHORA PARASITICA INOCULATION AND INTENSITY OF VESICULAR‐ARBUSCULAR MYCORRHIZAE IN CITRUS
Authors: DAVIS R. M. , MENGE J. A. 
Published: May 2006

SUMMARYShoot weights, root weights, and percentages of healthy roots of mycorrhizal (Glomus fasciculatus) sweet orange inoculated with Phytophthora parasitica (20 or 50 chlamydospores g‐1 soil) were greater than those of non‐mycorrhizal seedlings at either inoculum density. However, the growth response to mycorrhizal infection was reduced 23 and 58% by inoculation with 20 and 50 chlamydospores per g soil, respectively. Mycorrhizal infection was not reduced by P. parasitica at 20 chlamydospores per g soil, but was reduced 72% in seedlings inoculated with 50 chlamydospores per g soil. The latter also reduced the phosphorus content of the leaves. Tests with seven mycorrhizal fungi on two citrus rootstocks showed that different VA infections might confer variable tolerance or resistance to P. parasitica. Two fungi, Glomus mosseae and Gigaspora margarita, not isolated from nor as nutritionally efficient as others on citrus, conferred tolerance or resistance.
ACCUMULATION OF PHYTOALEXINS IN COTYLEDONS OF FRENCH BEAN (PHASEOLUS VULGARIS L.) FOLLOWING TREATMENT WITH TRITON (T‐OCTYLPHENOL POLYETHOXYETHANOL) SURFACTANTS
Authors: HARGREAVES J. A. 
Published: May 2006

ABSTRACTTriton surfactants induced accumulation of phytoalexins in cotyledons of the French bean. The degree of accumulation was related to the phytotoxicity of the surfactant, which was dependant upon the length of the polyethoxyethanol side chain. Triton X‐35, which induced the production of large amounts of phytoalexins, killed the outer epidermal cells and two to three layers of underlying sub‐epidermal cells. Cells adjacent to these dead cells were affected but not killed by this treatment.The main group of isoflavonoids formed were the 5‐hydroxyisoflavonoids (kievitone and licoisoflavone A). The 5‐deoxyisoflavonoids (phaseollin, phaseollidin and phaseollinisoflavan) were present only at low concentrations.When cotyledons treated with Triton X‐35 were incubated in distilled water the major induced isoflavonoids were kievitone, which was located mainly in the cotyledons, and a compound tentatively identified as 2′,4′,5,7,‐tetrahydroxyisoflavone, which was detected in the water medium.These results support the hypothesis that phytoalexin accumulation in the French bean is part of a wound response and involves an interaction between dead cells and their neighbouring live cells.