Reserve Substances Research Articles

冷害年（2003）に宮城県下で深水および浅水管理栽培された水稲の種子胚乳における貯蔵物質の蓄積構造

冷害年（2003）に宮城県下で深水および浅水管理栽培された水稲の種子胚乳における貯蔵物質の蓄積構造

Effect of temperature on synthesis of polyphosphates in Yersinia pseudotuberculosis and Listeria monocytogenes under starvation conditions

It was found that at low temperature (6-8 degrees C) in the absence of nitrogen supply and at the presence of phosphate ions in the medium, Yersinia pseudotuberculosis and Listeria monocytogenes are able to actively synthesize reserve substances as polyphosphates. Most of the bacterial polyphosphates are alkali-soluble, especially at the preliminary stage of cell growth (lag-phase). This is proved by electron microscopic studies of ultrastructure of model microorganisms. During a long starvation period under conditions of carbon and energy source deficit, L. monocytogenes and Y. pseudotuberculosis consume this biopolymer for biosynthetic and bioenergetic processes.

Effects of Shading and Flag Leaf or Awn Removal on Structure of Reserve Substances Accumulation in the Grain Endosperm of Two-rowed Barley

Effects of Shading and Flag Leaf or Awn Removal on Structure of Reserve Substances Accumulation in the Grain Endosperm of Two-rowed Barley

Accumulation Structure of Reserve Substances of "Hitomebore" Rice Seeds with Deep or Shallow Flooding Management in the Year of Cool Weather Damage

Accumulation Structure of Reserve Substances of "Hitomebore" Rice Seeds with Deep or Shallow Flooding Management in the Year of Cool Weather Damage

Variación de los índices gonádico, de rendimiento muscular y de la glándula digestiva de Spondylus princeps (Gray, 1825) (Mollusca: Bivalvia) en Isla Cedros y Punta Eugenia, México

The variation of the gonadal, muscular yield and digestive gland indexes was studied in Spondylus princeps from Punta Eugenia and Isla Cedros, Mexico. Specimens were collected from March to July 1997 and from August to December 2003. Gonadal indexes from 2% to 4% suggest reproductive inactivity from March to May and from October to December. The sustained increase in the index from May to July suggests gonadal maturity (10% of the soft tissues weight in July); the index decreased from 10% to 2% from July to October, corresponding with the spawning period. The muscular yield index showed high values (45-50%) from March to June and diminished sustainedly until August, when the lowest value (37%) was attained. Muscular yield index recovered during September and October with values of 45% staying around 40% during November and December. The muscular yield suggests that during the gonadal maturity, the energy stored in the abductor muscle is not used until the spawning season. The digestive gland index showed the highest value in March and decreased lightly until June, indicating that the energetic substances stored in the digestive gland sustain together with the external food, the gonadal development from July up to September when a fast decrease of the index occurs, suggesting that reserve substances in the digestive gland and in the muscle are used during the spawning period.

Senescence of Unfertilised Flowers in Epiphyllum Hybrids

Epiphyllum hybrids served as a model for the study of reserve remobilisation from unfertilised flowers to the mother stem tissues. Early phases of the tube senescence characterised by wilting were connected with degradation and transfer of reserve substances to the somatic organs of the mother plant. The degradation process began in perianth and stamens and continued through the successive zones (receptacular, pericarpellar and pedicellar) of the flower tube. The phloem-mediated backward substance transport was naturally indicated by the red pigment of the perianth -- cactorubin, while integrity of cells and tissues and green colour of the flower tube were still preserved. For the later phases of senescence the loss of permeability and successive breaking of the cell integrity, connected with the colour change of the tube from green to red was evident. The functioning of vascular bundles especially their phloem parts conducting dissolved substances to the sinks in mother stem organs were preserved until late stages of senescence. The recycling and remobilisation of nutrients from all parts of unfertilised ovary and ovules may be considered as a part of the life strategy in the family Cactaceae as well as in other taxa evolutionarily adapted to life in extreme environmental conditions.

Nutrient stress causes akinete differentiation in cyanobacteriumAnabaena torulosa with concomitant increase in nitrogen reserve substances

Addition of nitrogen source (nitrate), carbon sources (acetate, citrate and fructose), depletion of nutrients (phosphate-free nitrate medium), dilution of medium (2, 4 and 8 times diluted nitrate medium) under unaerated conditions induced akinete differentiation in Anabaena torulosa. Aerated cultures under the same conditions did not differentiate akinetes. The amounts of reserve metabolites--glycogen and cyanophycin (multi-L-arginyl-poly-L-aspartic acid) granule polypeptide (CGP)--were determined in unaerated and aerated cultures, and at different stages of growth and akinete differentiation. The addition of nitrate, acetate, citrate and fructose under unaerated conditions resulted in the accumulation of glycogen and CGP in higher amounts after 4 d (akinete initiation); the CGP content further changed at mature free akinetes phase. Higher accumulation of reserve products was also observed under nutrient deficiency (phosphate-depleted or diluted media) after 4 d of cultivation. Under aerated conditions reserve product accumulation was considerably lower. Thus a low accumulation of reserve products in aerated cultures showed that aeration probably somehow relieves the organism from a nutritional stress.

Influence of flowers per cluster, fruit-set and berry weight on cluster weight in Verdejo grapevine (<em>Vitis vinifera</em> L.)

<p style="text-align: justify;">Estimation of yield has always been one of the greatest concerns in the wine-making industry, which is why researchers have attempted to create models and methods that make accurate predictions. However, the variability of the yield components, which depends on the environmental factors, like light and temperature, and on cultural and natural factors which affect vigor, water status, photosynthetic and hormonal activity and the accumulation of reserve substances, make the prediction of the future harvest very difficult to calculate. In certain situations, fertility expressed as the number of bunches, tends to display very stable values from one harvest to the next. The weight of the cluster is the performance factor that has the greatest variability and mostly causes the variations in production. In this report, we analyze the influence of the number of flowers per cluster, the fruit-set percentage, the number of berries per cluster and the berry weight in the variability of the cluster weight of the Verdejo variety (<em>Vitis vinifera</em> L.). The cluster weight and its components have been determined along canes of 6 and 10 buds, in the harvests of 1999, 2000 and 2001. The yield component upon which cluster weight variation fundamentally depends has been the number of berries it contains, whereas the berry weight has had much less of an effect. The number of berries per cluster is mainly determined by the number of flowers per inflorescence, a yield component which has gone so far as to explain, by itself, an average of 75%of the variability in the number of berries per cluster and 70 % of the variability of the cluster weight. Despite the possible influence that the fruit-set percentage may have on the variability in the number of berries per cluster, measuring the number of flowers per inflorescence would make it possible to know, to a reasonable level of accuracy, the future number of berries per cluster long before the harvest date. At the same time, if a yield estimate is not needed far in advance, prediction of the future cluster weight can be determined by measuring the number of berries per cluster 15 or 20 days after fruit-set time, when the falling of small fruits is right minimal. In any case, whether by using the number of flowers per inflorescence or the number of berries per cluster, the berry weight on the harvest date would be the only yield component that would require estimation, which is usually much easier to achieve due to the lesser variability seen in this parameter.</p>

Asparagine—ab initio structural analyses

Amino acids can be defined separately by the unique characteristics rendered to each amino acid molecule as a result of the varying reactive abilities of their side chains. Asparagine is among less than a handful of amino acids capable of reacting with saccharides (referring to the biologically active l-asparagine stereoisomer). Recently, it has been found that asparagine in potatoes reacts with glucose through a Maillard reaction to form acrylamide, a neurotoxin and potential carcinogen. Otherwise, its side chain can react to form N-glycosidic bonds with oligosaccharides, establishing a prevalent role in the glycosylation of proteins during the latter phase of protein synthesis. In addition to regulating glycoprotein assembly, asparagine is critical for specific protein functions, such as antibodies, collagen assembly, enzyme function, and cell-to-cell recognition. Asparagine is involved in the metabolic control of cell functions in nerve and brain tissue, and is important as a nitrogen reserve substance. Determination of the conformations adopted in vitro and in vivo is crucial to elucidating the mechanism by which asparagine functions in its various roles. Structural analyses are performed using ab initio calculations in the gaussian98 program for Linux.

Variation in Crown and Root Organic Reserves Among Lucerne Genotypes of Different Morphology and Flower Colour

AbstractPrevious evidence indicates that differences in the concentration of underground organic reserves can drive the survival and growing ability of lucerne under cold and defoliation stresses. In order to provide the selection process with further information on compounds that may influence plant performance under grazing, we assessed variations in cold‐season concentrations of nitrogen and carbon reserves on genotypes that had been identified for morphological features that possibly enhance grazing tolerance. The selected genotypes encompassed distinct morphological patterns (defined as ‘models’) and different taxa within the Medicago sativa complex, as shown by different flower colours. Crown concentrations of reserves were determined on 90 genotypes, whereas root concentrations were measured on a subsample of 15 genotypes. Wide intergenotypic variation was observed for all reserve substances. Comparisons among models and among flower colour classes highlighted the high concentrations of crown carbohydrates and root and crown‐soluble proteins of the model coded as ‘D1’, characterized by prostrate, rhizomatous habit and long dormancy, which largely corresponded to plants with yellow or variegated flowers, typical of ssp. falcata and × varia, respectively. There was a strong ‘flower colour × storage organ’ interaction for sugar concentration, and the results suggested a preferential compartment of sugars in the roots of purple‐flowered genotypes that belonged to the ssp. sativa. A rank correlation analysis indicated a positive relationship between persistence after two years under grazing of half‐sib progenies deriving from 19 genotypes out of the 90 and crown concentrations of carbohydrates of the 19 mother plants.

A light and electron microscopy study on the formation, structure and germination of akinetes of Stigeoclonium tenue (Chaetophorales, Chlorophyceae)

Akinete formation in Stigeoclonium tenue (AG) KUTZ began under unfavourable conditions (exhaustion of nutrients and/or evaporation of the culture medium). Cells from both prostrate and erect portions produced akinetes. A gradual change in the shape of vegetative cells was observed. They lost their typical straight edges and acquired an oval contour with constrictions at the level of the transverse cell walls. At the ultrastructural level, the changes were: 1) accumulation of starch and lipids as reserve substances; 2) disorganization of the chloroplast; 3) reduction of the vacuole until it disappeared in mature akinetes; 4) thickening of the wall resulting from the synthesis of both an additional new own wall next to the parental wall and a mucilage external layer; 5) disorganization of the plasmodesmata in the transverse walls of vegetative cells. All of these drastic cytological changes are essential to the development of akinetes which provide S. tenue with an effective survival mechanism under unfavourable conditions.

Effect of arbuscular mycorrhizae on cv. carmem avocado plants1

The effects of six species of arbuscular mycorrhizae (AM) on root colonization, nutrient uptake, reserve substances, and vegetative development of cv. Carmem avocado (Persea sp.) plants were evaluated. Glomus clarum Nicol. and Schenck, Glomus etunicatum Becker and Gerd, Glomus manihotis How, Siev and Schenk; Acaulospora scrobiculata Trappe, Scutellospora heterogama Nicol and Gerd and Gigaspora margarita Becker and Hall were inoculated on avocado seedlings, onto which Carmem scions were grafted. Responses of the avocado plants to the different AM species 7 months after grafting were distinctly different. Scutellospora heterogama, A. scrobiculata, G. etunicatum, and G. clarum more thoroughly colonized the root system of the avocado plants, resulting in enhanced nutrient uptake and higher accumulation of reserve substances, which favored vegetative growth. The mutualism between avocado plants and G. margarita or G. manihotis was not efficient under the conditions of the present experiment. *Part of the dissertation of the first author towards the degree of Master of Science.

Formation and structure of egg capsules in scale insects (Hemiptera, Coccinea): I. Ortheziidae

The paired ovaries of the investigated species are composed of 20–30 ovarioles of a telotrophic-meroistic type. Each ovariole is subdivided into an apical tropharium (=trophic chamber) and a vitellarium that contains a single developing oocyte. This oocyte is surrounded by a mono-layered follicular epithelium that is responsible for synthesis of precursors of egg envelopes. In Orthezia, synthesis and secretion of precursors of egg envelopes (=choriogenesis) and accumulation of reserve substances in the oocyte cytoplasm (=vitellogenesis) start at the same time. The egg capsule is composed of two envelopes: an internal, thick vitelline envelope and an external, very thin chorion. The egg surface is covered with numerous, irregularly arranged waxy filaments of spiral shape. Eggs are devoid of the micropylar, aeropylar and hydropylar openings.

Formação das substâncias de reserva durante o desenvolvimento de sementes de urucum (Bixa orellana L. - Bixaceae)

As sementes de urucum não germinam durante os primeiros estádios de seu desenvolvimento devido em parte à insuficiência de materiais de reserva. A análise in situ do material de reserva das sementes revelou que ocorrem principalmente proteínas e amido nas células do endosperma. Durante os estádios iniciais do desenvolvimento, o formato dos grãos de amido mostrou-se elíptico, devido a menor quantidade de amilose. Durante o desenvolvimento, os grãos tornaram-se mais esféricos devido ao aumento de amilose em relação a amilopectina. As células do endosperma não possuem corpos protéicos, mas armazenam proteínas. Durante o desenvolvimento houve acúmulo de proteínas dispersas pelo citoplasma. No estádio final do desenvolvimento, as proteínas tornaram-se compactadas devido à desidratação das sementes, que faz parte do processo global de maturação de sementes ortodoxas. A utilização de fluorescência natural revelou a presença de aminoácidos aromáticos no conteúdo protéico, principalmente triptofano e tirosina. Nestas sementes o conteúdo de matéria seca alcançou o máximo quando a semente apresentou cerca de 60% de umidade. Nesta fase a semente apresentou capacidade germinativa máxima.

Comparison between somatic and zygotic embryo development in Quercus robur L.

ABSTRACT Somatic embryogenesis from juvenile explants as an efficient way for oak clonal propagation is drastically limited by the low rate of embryo germination. A comparison of the development of immature somatic and zygotic embryos, and a study of the changes in sugar content and lignin accumulation during somatic versus zygotic embryo development were conducted in view of understanding the effect of reserve substance deficiency upon somatic embryo maturation. A morphological comparison of somatic and zygotic embryos led to the identification of 4 to 7 similar developmental stages in both types of embryos, thus indicating that the accumulation phase in both zygotic and somatic embryos occurs at the same stage, when the cotyledons became thicker and opaque. Carbohydrate analysis showed the presence of glycerol, inositol, mannitol, galactose, trehalose, xylose, arabinose, glucose, fructose and sucrose in all stages of zygotic and somatic embryo development, but in different amounts. The amount of glycerol, inositol, glucose and sucrose during the early stages is larger in zygotic embryos than in somatic ones, but the time course of their accumulation is similar in both types of embryos. Lignin content, which increased continuously during development, showed a similar behaviour in zygotic and somatic embryos. In somatic embryos which were able to germinate, lignin content was higher than in nongerminating embryos at the same stage.

Hermodactylus tuberosus L. (Iridaceae) pollen organisation before and after anther dehiscence

ABSTRACT The morphology, cytology and viability of Hermodactylus tuberosus L. (Iridaceae) pollen were examined from the first mitosis until maturation and after anther opening. During maturation, the pollen coat becomes modified, and the vegetative cell cytoplasm accumulates several types of reserve substances. In the vegetative cell cytoplasm, starch is quickly utilised whereas lipid inclusions of different dimensions, shape and composition occur during pollen maturation. Pollen from opened anthers have a thin pollen coat; the cytoplasm has mostly lipid reserves, and many small vesicles and vacuoles. It is similar in size or larger than pollen located inside the anther, and its viability does not decrease until one day after anther dehiscence. Large osmiophilic bodies, different from those of the vegetative cell cytoplasm, are present in the generative cell cytoplasm starting from the first stage of pollen development. The poorly developed pollen coat in pollen from opened anthers suggests that it plays a minor role in attracting insects for pollination. The size and structural and ultrastructural features of mature pollen indicate that it does not undergo dehydration and possesses sufficient vigour for immediate germination.

Effects of Nitrogen Application on the Development and Accumulation of Protein Bodies in Developing Rice Seed

We examined the nature of protein bodies affected by nitrogen application in developing rice endosperm using scanning and transmission electron microscopes. Protein body type II, Pb-II, was observed at the first week after heading independent of nitrogen application, whereas protein body type I, Pb-I, was not observed in either the low nitrogen or non-fertilized group. However, in the high nitrogen group, Pb-I was also observed at 1 week after heading. Pb-I was formed by enlargement of endoplasmic reticulum cisternae, but Pb-II had a close relationship with the Golgi apparatus and was accumulated in the envelope-like vacuole. The smallest protein body, Pb-III, about 0.6-0.8 μm in diameter, appeared at 2 weeks after heading, and the amounts of this protein body increased substantially at 3 weeks after heading. This protein body also originated from endoplasmic reticulum cisternae. Pb-I was observed only in cytoplasm, but, Pb-II appeared in both the endoplasmic reticulum and envelope-like vacuole. The amount of protein bodies in the rice endosperm cell varied with the cultivar and amount of nitrogen applied. In cv. Koshihikari (Japonica), the application of much nitrogen increased the amount of protein bodies not only in the subaleurone, but even in the fifth layer from the aleurone layer. However, in cv. Belle patna (Indica), the application of much nitrogen increased the amount of protein bodies up to the sixth ayer of aleurone layer, and caused the accumulation of a few protein bodies even in the central part of endosperm. It was concluded that storage protein transported by Golgi vesicles and rough endoplasmic reticulum (RER) plays an important role in the accumulation of reserve substances in rice seed. Development of mitochondria and RER was enhanced by the application of nitrogen.

Metabolism of Poly-β-Hydroxybutyric Acid in Yersinia pseudotuberculosis and Listeria monocytogenes Cultivated at Different Temperatures

A comparative investigation of the intracellular content of poly-β-hydroxybutyric acid showed that Yersinia pseudotuberculosis strains accumulated, on the average, lower amounts of this reserve substance than Listeria monocytogenes strains. The intracellular pool of poly-β-hydroxybutyric acid was responsible for the growth of the bacteria at low temperatures (4–6°C) in the absence of any exogenous carbon and energy source.

Reserve substances and storage of Cyathea delgadii Sternb. spores

The spores used were collected from a population of trees of Cyathea delgadii Sternb. growing in a gallery forest at the Reserva Biologica e Estacao Experimental de Moji Guacu, Sao Paulo state, Brazil (22°18’S and 47°11’W). The germination of spores of Cyathea delgadii decreases with time when kept in closed bottles under storage at 4°C in darkness. Germination is still very high after storage for one year. Spores stored for three years do not germinate. The results also show a decrease in soluble proteins and an increase in starch after several months storage.

Changes in Ultrastructure of Phaseolus Vulgaris L. Cotyledons Associated with their Modulated Life Span

French bean (Phaseolus vulgaris L.) cotyledons lost most of their reserve substances during several early days of germination and turned green. In cotyledon mesophyll cells of one-week-old seedlings, plastids were represented predominantly by amyloplasts (starch grains) and chloroamyloplasts, and the cells appeared to be metabolically highly active. Cell heterogeneity associated with distance of the cells from cotyledon vascular bundles was evident. Only mesophyll cells near to the bundles were rich in plastids. In two-weeks-old intact bean plants, the cotyledons were yellow and shrunken, and their cells were nearly "empty". The plastids in them were represented by senescent plastids (gerontoplasts) only. In the gerontoplasts as well as freely in cytosol, fluorescent lipoid inclusions were accumulated. This cotyledon development was more or less independent of irradiance. In "decapitated" bean plants, senescence of mesophyll cells and plastids was slowed down considerably, and the life span of the cotyledons was prolonged.