Reserve Substances Research Articles

Some physiological and biochemical parameters of underyearling Laxmann’s shrews (Sorex cecutiens Laxmann) and even-toothed shrews (Sorex isodon Turov) under different population densities

Based on the results of a study conducted in the Buyunda River basin (tributary of the Kolyma River) in 2006–2010, influence of the population density of shrews (Sorex) on some physiological and biochemical parameters (glycogen and lipids in the liver, relative weight of the spleen, white and brown adipose tissue, cellularity of bone marrow) was investigated. The content of energy reserve substances was found to be closely connected with the number of animals (fat deposits had inverse relation; glycogen content in the liver had direct relation). Other physiological-biochemical parameters had no significant relation to the population density, although such tendency was observed for the content of brown fat and cellularity of bone marrow tissue in Sorex isodon, and for the relative weight of the spleen in both species of shrews. We suggest that the identified physiological changes indicate irregular feeding of animals in years with higher population densities.

Russian

Damage of seeds which leads to destruction of the crystal lattice and the phase transition of polymers is formed under the pulse pressure (PP) treatment. Biopolymers such as starch compressed under specific conditions can be changed from crystalline to a glassy state; this transition is known to extend the life of seeds. The aging of seeds is involved in the enzymatic glycosylation of proteins and nucleic acids. Reducing sugars which have been produced in seeds by non-enzymatic hydrolysis enter into reaction of glycosylation with proteins and amino acids actively. The authors studied the water absorption by seeds of buckwheat (Fagopyrum esculentum Moench., cultivar Saulyk) treated by PP. The values of PP which were used to treat had an influence on water absorption during the first hours of imbibition. When water content was 60%, hydrolysis of reserve substances could begin, so water potential was created by osmotically active molecules. Gibbs energy calculation by method of groups' contribution indicated the reduction in probability of starch hydrolysis in plant seeds during transition from the crystalline to the glassy state. Keywords: pulse pressure; biopolymer; destruction; starch; buckwheat; hydrolysis. Введение. В качестве фактора, действующего на растения, было выбрано импульсное давление (ИД), создаваемое прохождением ударной волны. ИД в интервале 3-35 МПа способствует стимулированию физиологических процессов в семенах и растениях, ведущих к

Underground system of Mandevilla atroviolacea (Stadelm.) Woodson (Apocynaceae, Apocynoideae) from the Brazilian high-altitude grassland

The underground systems of plants show the most varied structures adapted to survival in unfavorable environmental conditions. For instance, long-term droughts may induce the development of either water and reserve substances or vegetative propagation structures. Since Mandevilla atroviolacea is a species found at high altitudes on rocky outcrops, this study aimed to provide information on the morpho-anatomy of the underground system of this species that may assist in understanding the adaptive strategies at play. Samples from the underground system of three young and two mature plants collected in the field were sectioned and processed according to standard plant anatomical techniques. The upper area of the underground system corresponds to a xylopodium, while the lower is a tuberous stem organ. Tuberous roots account for the majority of the underground system. The increase in tuberous root diameter results from the action of a typical cambium. The high shoot-forming potential and storage of water and reserve substances observed in the underground system of this species are important strategies for it to survive in this habitat.

Effect of Hot Air Drying on Ultrastructure of Crambe Seeds

This study was conducted to evaluate the morphologic modifications in tissues of the fruit and seed of the crambe (Crambe abyssinica Hochst. Ex R.E. Fr.) after drying at different temperatures. Fruits with a water content of 0.38 kg water/kg dry matter were harvested and manually homogenized. Drying was accomplished at 35, 45, 60, 75, and 90°C and at 21,9,7,5, and 2% relative humidity, respectively. After drying, the structure of the pericarp and tegument of the seed were evaluated and the embryo was removed from the fruit/seed for morphological analysis (structural and ultrastructural and the histolocalization of reserve substances). Drying at different temperatures did not affect the cellular structure of the tissues composing the pericarp of the fruits, but it disorganized the structure of the seed tegument. The cells of the tegument and cotyledons presented a contraction in their volumes. The lowest contractions in the cellular volumes of both the tegument and cotyledons occurred after drying at 35 and 45°C. The cytoplasm of the cotyledon cells contains oil drops and the protein bodies contain protein granules and starch grains. There were no changes in the cellular walls of the embryos of the fruits dried at different temperatures; however, ungluing of the medium lamella occurred. This damage occurred with greater intensity after drying at temperatures above 60°C. The form of the oil drops in the cytoplasm of the cotyledon cells was altered after drying. At temperatures above 60°C, the drops broke up and coalesced. After drying at 45 and 60°C, the form of some protein bodies was altered, whereas at 75 and 90°C coalescence of the protein bodies occurred in some cells. It was concluded that the identified alterations can affect the physiologic quality of crambe seeds.

Alterations in seed reserves of Dalbergia nigra ((Vell.) Fr All. ex Benth.) during hydration

Seed imbibitions is the first stage of the germination process and is characterized by the hydration of tissues and cells and the activation and/or induction of the enzymes responsible for mobilizing reserves for respiration and the construction of new cell structures. The objective of this study was to investigate the alterations in reserve substances during slow hydration of Bahia Rosewood (Dalbergia nigra) seeds in water. Seeds from two different lots (Lot I and II) were placed in saturated desiccators (95-99% RH) to hydrate at 15 and 25 °C until water contents of 10, 15, 20 and 25% were reached. At each level of hydration, changes in lipid reserves, soluble carbohydrates, starch and soluble proteins were evaluated. The mobilization of reserves was similarly assessed in both lots, with no differences being observed between the two hydration temperatures. Lipid contents showed little variation during hydration, while the contents of soluble carbohydrates and starch decreased after the 15% water content level. Soluble proteins showed a gradual tendency to decrease between the control (dry seeds) up to 25% water content.

Transitory Carbohydrate Reserves in Vegetative Organs of Coconut Under Different Growth Conditions and Its Relation with Reproductive and Vegetative Growth of The Palm

The study evaluated the non structural carbohydrate reserves in vegetative organs and vegetative and reproductive growth rates of a 25 year old Tall x Tall coconut (Cocos nucifera L) during the peak season of coconut yield (May/June) under S2 and S4 Land Suitability Classes (LSC) in three Agro Ecological Regions (WL3, IL1a and DL3). Trunk (inner and outer), root (new roots and mature roots) and leaf samples (petiole, leaf blade and leaf ekel from 9th, 14th and 22nd fronds) were collected, total soluble sugars (TSS) and starch concentrations were analyzed and TSS and starch reserves at palm level were estimated. Growth rate of trunk and leaves (vegetative) and developing nuts of all bunches of a palm (reproductive) were measured. The highest (3.86 kg month-1) and the lowest (0.81 kg month-1) reproductive growth rates and the highest (3.8 kg month-1) and the lowest (2.1 kg month-1) vegetative growth rates were found in the palms grown under S2 and S4 LSC in the DL3, respectively. There was a constant vegetative growth rate of 3.3 kg month-1 for the palms in WL3 and IL1a irrespective of the AER or LSC. The most dominant nonstructural reserve substance in the vegetative organs of coconut was soluble sugars (TSS) and the starch concentration was approximately half the TSS concentration in all vegetative parts irrespective of the AER or the LSC. TSS and starch showed a marked pattern of distribution, with highest concentration in trunk (114-134 mg g-1 TSS and 60-83 mg g-1 starch), intermediate in leaves (69-117 mg g-1 TSS and 33-69 mg g-1 starch) and lowest in roots (22-79 mg g-1 TSS and 17-33 mg g-1 starch). The highest TSS and starch reserves in leaf compartments (kg per palm) were found in the S2-grown palms of the DL3 which had the highest reproductive and vegetative growth rates during May-June season. DOI: http://dx.doi.org/10.4038/cocos.v19i2.4753

Respiratory metabolism of the pea aphid, Acyrthosiphon pisum (Hemiptera: Aphididae)

The respiratory metabolism of different polyphenic forms of the pea aphid, including wingless and winged asexual females (virginoparae), sexual females (oviparae) and winged or wingless adult males, was investigated using a micro-respirographic method. The records revealed sub-nanoliter amounts per min of O2 consumption or CO2 output. Respiratory metabolism of individuals was monitored for 3 to7 h after removal of the aphid from the food plant. Most of the recordings were for relatively large (3.5 mg), wingless asexual females (virginoparae). These aphids exhibited a continuous and very regular respiratory gas exchange (example: specimen of 3.5 mg body mass consumed 180 nl of O2 per min; released simultaneously 300 nl CO2 per min; = standard metabolic rate of 3085 µl O2 / g / h; R.Q. = 1.66). This continuous pattern of respiration occurred only when the aphids were kept at relatively high humidity. By contrast, aphids of various seasonal forms exhibited discontinuous respiratory gas exchange when kept in relatively dry air (atmospheric, room conditions). These patterns can be briefly described as follows: (a) Short and rather small micro-cycles of CO2 emission, manifested usually by the sudden expiration of 60-120 nl of CO2 once every 5 min; (b) Larger bursts of 240-480 nl of CO2 with a periodicity of one hour; (c) Enormously large, discontinuous bursts of 10-14 µl CO2, duration 10-30 min, repeated with a periodicity of several hours. There was no constant pattern of diffusive CO2 emission (DGC). The aphids exhibited a pattern of CO2 release that was appropriate for the external conditions, such as temperature and humidity, and internal physiological conditions such as metabolic activity, availability of reserve substances (carbohydrate, lipid) and water. Certain stages (wingless virginoparae) exhaled volumes of CO2 greatly in excess of their O2 consumption (R.Q. over 1.5). Sudden exhalations of CO2 from the body were a consequence of a bulk production and outflow of CO2 and not due to the diffusion of CO2 previously accumulated within the tracheal system. Due to their generally high metabolic activity (1142 to 6780 µl O2 / g / h), aphid tissue and organs produced relatively large amounts of metabolically formed carbonic acid. The resulting respiratory acidaemia was moderated by outbursts of gaseous CO2, liberated from liquid carbonate buffers by a regulatory mechanism based on enzymatic hydration and neutralization of carbonic acid by discontinuous formation of gaseous CO2.

Colleters in Cariniana estrellensis (Lecythidaceae): structure, secretion and evidences for young leaf protection1

The occurrence of colleters in Eudicotyledons is probably significantly underestimated as a consequence of the scarcity of structural studies directed towards them and the difficulties to determine their function. The present work aims to report the occurrence of colleters in Cariniana estrellensis and describe their morphological and functional aspects; for this, leaves at different stages of expansion were collected and studied using light, and scanning and transmission electron microscopy. The young leaves of C. estrellensis are involute and have colleters along the margins. These colleters appear to be functional in very young leaves and produce pectic secretions that spread over the entire leaf surface. The colleters are clavate and sessile, and have a central axis composed of parenchymatic cells as well as a secretory epidermis covered by a cuticle. The central cells have vacuolate cytoplasm with few organelles and reserve substances. The cytoplasm of the epidermal cells has numerous dictyosomes during the secretory phase, with few plastids and mitochondria. The secretions coating on the leaf surfaces appear to contribute to maintaining the water balance of the young leaves, thus the main function of the colleters in this species appears to be to protect the leaves from excessive transpiration loses.

Morpho-anatomical features of underground systems in six Asteraceae species from the Brazilian Cerrado

In the Brazilian Cerrado (neotropical savanna), the development of bud-bearing underground systems as adaptive structures to fire and dry periods can comprise an important source of buds for this ecosystem, as already demonstrated in the Brazilian Campos grasslands and North American prairies. Asteraceae species from both woody and herbaceous strata have subterranean organs that accumulate carbohydrates, reinforcing the adaptive strategy of these plants to different environmental conditions. This study aims to analyse the morpho-anatomy of underground systems of six species of Asteraceae (Mikania cordifolia L.f. Willd., Mikania sessilifolia DC, Trixis nobilis (Vell.) Katinas, Pterocaulon alopecuroides (Lam.) DC., Vernonia elegans Gardner and Vernonia megapotamica Spreng.), to describe these structures and to verify the occurrence and origin of shoot buds, and to analyse the presence of reserve substances. Individuals sampled in Cerrado areas in São Paulo State showed thick underground bud-bearing organs, with adventitious or lateral roots and presence of fructans. Xylopodium was found in all studied species, except for Trixis nobilis, which had stem tuber. The presence of fructans as reserve, and the capacity of structures in the formation of buds indicate the potential of herbaceous species of Asteraceae in forming a viable bud bank for vegetation regeneration in the Brazilian Cerrado.

Remembering Nutrient Quality of Sugar in Drosophila

Taste is an early stage in food and drink selection for most animals [1, 2]. Detecting sweetness indicates the presence of sugar and possible caloric content. However, sweet taste can be an unreliable predictor of nutrient value because some sugars cannot be metabolized. In addition, discrete sugars are detected by the same sensory neurons in the mammalian [3] and insect [4, 5] gustatory systems, making it difficult for animals to readily distinguish the identity of different sugars using taste alone [6-8]. Here we used an appetitive memory assay in Drosophila [9-11] to investigate the contribution of palatability and relative nutritional value of sugars to memory formation. We show that palatability and nutrient value both contribute to reinforcement of appetitive memory. Nonnutritious sugars formed less robust memory that could be augmented by supplementing with a tasteless but nutritious substance. Nutrient information is conveyed to the brain within minutes of training, when it can be used to guide expression of a sugar-preference memory. Therefore, flies can rapidly learn to discriminate between sugars using a postingestive reward evaluation system, and they preferentially remember nutritious sugars.

Ontogenetic changes in accumulation of rhizomes in monoclonal patch of Miscanthus sinensis Anderss. in warm temperate region of Japan

To determine the main benefits of clonal expansion of Miscanthus sinensis patches (monoclones), we observed the annual pattern of the areal expansion of a number of M. sinensis patches and examined how the quantity of rhizomes in such patches is related to changes in their basal area. To forage for nutriments, a patch must continuously widen its habitat. Patches annually expanded centrifugally by sympodial branching of short rhizomes, which originated in tillering that occurred more than once a year. However, the basal area of the patches approached a ceiling as the patches aged. Both the number and the weight of rhizomes in the patches continued to increase as long as the basal area expanded. The mean weight of rhizomes in patches also initially increased quickly, but then reached a ceiling as the clones expanded. Similarly, the amount of reserve substance per shoot in the patches increased asymptotically along with the clonal expansion, depending on the rhizome mass allotted to each shoot. These results suggest that, in the clonal growth of M. sinensis patches, the accumulation of reserve matter in the rhizomes is more important than foraging in new areas.

Soluções de manutenção na pós-colheita de Chrysanthemum morifolium cv. Dragon

O desenvolvimento e uso de técnicas que prolonguem a durabilidade das flores, mantendo a qualidade do produto, é imprescindível para redução de perdas pós-colheita. Objetivou-se, neste trabalho, avaliar soluções de manutenção, associadas ou não a sacarose, na manutenção da qualidade pós-colheita de hastes de crisântemos. O experimento foi conduzido sob delineamento inteiramente casualizado, em esquema fatorial, com cinco tratamentos e três repetições, com 2 hastes florais cada uma. Os tratamentos utilizaram água destilada; 8-HQC a 100 mg L-1; 8-HQC a 100 mg L-1 + sacarose a 50 g L-1, 8-HQC a 200 mg L-1; 8-HQC a 200 mg L-1 + sacarose a 50 g L-1. Foram feitas avaliações físicas: coloração, massa fresca e conteúdo relativo de água (CRA); avaliações químicas: açúcares redutores e pigmentos; e avaliações qualitativas: turgescência, cor das flores, e número de botões, flores entreabertas e abertas. A combinação de 8-HQC 200 mg L-1 + sacarose a 50 g L-1 foi a que apresentou melhor desempenho para a manutenção da qualidade das hastes florais, favorecendo a abertura de botões e a turgescência das lígulas. A sacarose contribuiu para uma melhor manutenção de substâncias de reserva na haste, que tiveram a sua vida de vaso estendida.

On-line monitoring of dielectrical properties of yeast cells during a stress-model alcoholic fermentation

This paper reports the use of on-line dielectric spectroscopy to monitor the effect of a technological stress on Saccharomyces cerevisiae during an alcoholic fermentation. The dielectric spectrum ( β dispersion) of a cell suspension depends on various variables related to cell state: cell concentration, cell size and cell viability as well as the states of the plasma membrane (membrane capacitance) and the cytoplasm (intracellular conductivity). Additional measurement methods (cell size, cell viability and cell counts) have been developed to identify the variables that describe the β dispersion and extract membrane capacitance and intracellular conductivity values. All measurements confidence intervals have been estimated in order to appraise the significance of the measured variations. In all the studied culture conditions, the amplitude of the β dispersion gave a reliable estimate of the viable cell volume fraction. The membrane capacitance value remained constant as long as the cells were viable (Cm = 0.6 μF cm −2) and dropped to zero at cell death, while the intracellular conductivity varied significantly depending on the growth phase and in response to stress (2 < σ in < 3 mS cm −1). Hypotheses are proposed to explain the evolution of intracellular conductivity by intracellular pH changes and synthesis/consumption of reserve substances such as trehalose.

The effect of amount of reserve substance on the growth of sprouted young plants in mulberry plants

The effect of amount of reserve substance on the growth of sprouted young plants in mulberry plants

Effects of ecological conditions on lipid composition of the liver and muscles in the daubed shanny, Leptoclinus maculatus

A comparative study on the lipid composition of the liver and muscles has been performed in daubed shanny caught in summer (July) in Arctic waters at three different sites (biotopes) along the north-western coast of Spitsbergen. In marine organisms living at high latitudes, lipids play an especially important role, primarily as reserve substances and as a factor influencing adaptation to severe environmental conditions. Since the ecology of daubed shanny is poorly known, the data obtained may be considered novel.

Post-Genomics Studies of Developmental Processes in Legume Seeds

Legume seeds are an important source of food and feed, and have been principally studied with a view to optimizing the composition of reserve substances starch, oligosaccharides, oil, and protein. The availability of genome and transcribed genome sequences for the legume model species Medicago

Phytic acid prevents oxidative stress in seeds: evidence from a maize (Zea mays L.) low phytic acid mutant

A maize mutant defective in the synthesis of phytic acid during seed maturation was used as a tool to study the consequences of the lack of this important reserve substance on seed survival. Data on germinability, free iron level, free radical relative abundance, protein carbonylation level, damage to DNA, degree of lipid peroxidation, alpha- and gamma-tocopherol amount and antioxidant capacity were recorded on seeds of maize B73 and of an isogenic low phytic acid mutant (lpa1-241), either unaged or incubated for 7 d in accelerated ageing conditions (46 degrees C and 100% relative humidity). The lpa1-241 mutant, compared to wild type (wt), showed a lower germination capacity, which decreased further after accelerated ageing. Whole lpa1-241 mutant kernels contained about 50% more free or weakly bound iron than wt ones and showed a higher content of free radicals, mainly concentrated in embryos; in addition, upon accelerated ageing, lpa1-241 seed proteins were more carbonylated and DNA was more damaged, whereas lipids did not appear to be more peroxidated, but the gamma-tocopherol content was decreased by about 50%. These findings can be interpreted in terms of previously reported but never proven antioxidant activity of phytic acid through iron complexation. Therefore, a novel role in plant seed physiology can be assigned to phytic acid, that is, protection against oxidative stress during the seed's life span. As in maize kernels the greater part of phytic acid (and thus of metal ions) is concentrated in the embryo, its antioxidant action may be of particular relevance in this crop.

A cysteine endopeptidase from tick ( Rhipicephalus ( Boophilus) microplus) larvae with vitellin digestion activity

The hard tick Rhipicephalus ( Boophilus) microplus is a blood-sucking ectoparasite. R. microplus free-living stage comprises egg development, hatching, and subsequent larval development until encountering a host. In order to complete the embryological development, this tick relies on yolk reserve substances, mainly vitellin (Vt), which is still present in the larval stage. The present study demonstrates presence and digestion of Vt in unfed R. microplus larvae. An increasing proteolytic activity is observed in larval development, as well as a decrease in total protein and in Vt content. Partial purification and characterization of a R. microplus larval cysteine endopeptidase (RmLCE) with Vt-degrading activity is also described. RmLCE has optimal activity at 37 °C at pH 5.0, being unstable at pH ≥ 7.5. This enzyme is active upon fluorogenic peptide substrates and is able to degrade Vt, its putative natural substrate. These results indicate that RmLCE has a role in supporting the nutritional needs of unfed R. microplus larva through Vt proteolysis, allowing survival until the first blood meal.

Ovarian maturation of the multi-spawning spider crab Maja brachydactyla (Decapoda: Majidae) with special reference to yolk formation

In the study of the reproductive biology of the spider crab Maja brachydactyla, the morphology of the female reproductive system and yolk formation have long been overlooked. Females spawn two or three times during their annual reproductive cycle in northern Spain (Galicia). The ovaries consist of two lobes. The right and left lobes are connected by a small cross-lobe at the level of the heart and merge at the posterior edge. Before merging, the ovaries descend to the ventral part of the body, joining the spermathecae in the vagina, which opens through a chitin tube to the gonopore, located in the sternite, at the level of the third walking leg. No morphological changes have been observed between either the different parts of the ovaries or the different annual spawning periods. At the start of vitellogenesis, the oocyte of M. brachydactyla is characterized by a large number of vesicles in the cytoplasm. These vesicles are surrounded by a unit membrane whose size increases as the oocyte matures and contain fine granular material including a variable number of ovoid, electron-dense granules. The vesicles are of diverse origin, although most of them develop directly from the mitochondria and the Golgi complex (endogenous phase of vitellogenesis). In a subsequent phase, a series of substances (principally lipoproteins) are incorporated into the ooplasma by means of micropinocytosis. These substances are also involved in yolk formation (exogenous phase of vitellogenesis). During vitellogenesis in M. brachydactyla, mitochondria play the most important role since they are not only the energetic centre of the cellule, but they also act as containers of high-energy reserve substances: the yolk granules.

Expressão diferencial de isoenzimas durante o processo de germinação de sementes de arroz em grandes profundidades de semeadura

O processo de germinação se constitui num complexo e ordenado conjunto de eventos fisiológicos e bioquímicos em que a semente é submetida logo após iniciar a absorção de água. A retomada do crescimento do embrião por causa da absorção de água envolve a reativação de muitas enzimas já presentes nas sementes e a sínteses de outras que irão hidrolisar as sustâncias de reserva, fornecer poder oxidante, energia, entre outras, para a germinação. A emergência das plântulas nas monocotiledôneas depende, principalmente, da profundidade de semeadura, e de muitos outros fatores tais como atributos genéticos e vigor das sementes, sendo que o embrião é nutrido de forma exclusiva, pelas reservas da semente. No presente trabalho, os padrões isoenzimáticos de Esterase (EST), Fosfatase Acida (ACP), Malato Deshidrogenase (MDH), Álcool Deshidrogenase (ADH) e Glutamato Oxalacetato Transaminase (GOT) de 34 ecótipos de arroz vermelho e 5 cultivares comerciais foram analisados durante o processo de germinação a 20 cm de profundidade com o objetivo de identificar variações de expressão diferencial nos sistemas isoenzimáticos analisados. Os cinco sistemas isoenzimáticos analisados apresentaram variações na expressão enzimática, principalmente quando comparados os padrões observados em semente seca e em plântulas em desenvolvimento. Dos resultados obtidos conclui-se que, há um diferencial de expressão nos genes que comandam a expressão das isoenzimas Esterase (EST), Fosfatase Ácida (ACP), Malato Deshidrogenase (MDH), Álcool Deshidrogenase (MDH) e Glutamato Oxalacetato Transaminase (GOT), nos processos de germinação de sementes de arroz.