Variation in the rate of hard seed breakdown of twelve tropical legumes in response to two temperature regimes in the laboratory

2000 ◽  
Vol 40 (3) ◽  
pp. 387 ◽  
Author(s):  
C. K. McDonald
Keyword(s):  
Evaluation Studies ◽  
Field Evaluation ◽  
Threshold Temperature ◽  
Breakdown Rate ◽  
Hard Seed ◽  
Temperature Regimes ◽  
Seed Content ◽  
Tropical Legumes ◽  
Breakdown Rates ◽  
Threshold Temperatures

Hard seed content is an important factor in the persistence of tropical pasture legumes as both high and low hard seed content can lead to poor recruitment. As temperature plays an important role in the breakdown of hard seed, the patterns of breakdown were measured in 27 seed lots of tropical legumes subjected to temperature regimes of 23–57˚C and 23–70˚C in laboratory ovens for 7 months. The seed lots represented 12 species comprising 15 released cultivars and 5 accessions showing promise in field evaluation studies. Each month seed was removed for germination testing and the proportion of hard, soft and dead seed in each seed lot was determined. After 7 months, the resulting pattern of hard seed breakdown was modelled to derive threshold temperatures for hard seed breakdown, values for the breakdown rate and quantification of the breakdown process. Desmanthus virgatus and Indigofera schimperi had the slowest rate of breakdown, while Aeschynomene americana had the fastest. The threshold temperature for most species was in the range 40–50˚C. However, there was considerable variation in threshold temperature and breakdown rates between seed lots of the same cultivar or accession and between species, which indicates that caution must be used before extrapolating the results to the field and to different climatic and/or management environments. Nevertheless, these results provide valuable information for the development of demographic models of legume persistence, and show that, while the species are well adapted to the temperature environments of northern Australia, specific management may be necessary to enhance the persistence of some of them.

scholarly journals The effect of temperature on the development and reproduction of Busseola fusca (Lepidoptera: Noctuidae)

2016 ◽  
Vol 107 (1) ◽  
pp. 39-48 ◽  
Author(s):  
J. Glatz ◽  
H. du Plessis ◽  
J. Van den Berg
Keyword(s):  
Larval Development ◽  
Busseola Fusca ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Single Male ◽  
Temperature Regimes ◽  
Threshold Temperatures ◽  
Thermal Constants ◽  
Lower Temperature ◽  
The Impact

AbstractThe effect of temperature on the reproduction and development of Busseola fusca was studied under laboratory conditions. Single male–female pairs were confined to oviposition chambers kept at 15, 20, 26 and 30 ± 1°C and a 14L:10D photoperiod. Data on reproduction parameters were captured daily. Oviposition occurred at all the mentioned temperatures but no fertility was recorded at 30°C. The total number of eggs laid per female moth was between 300 and 400 and the optimum temperature for oviposition and fertility was between 20 and 26°C. Larval development was studied at five different temperature regimes, i.e. 15, 18, 20, 26 and 30 ± 1°C and a 14L:10D photoperiod. The most favourable temperature as well as the upper threshold temperature for larval development was between 26 and 30°C. Total development period was 152.6–52.6 days, respectively, at 15°C, and 26–30°C. The thermal constants for B. fusca was 99.50, 536.48, 246.25 and 893.66°D and lower temperature thresholds were 10.36, 8.14, 8.99 and 8.84°C, for completion of the egg, larval, pupal and egg-to-adult stages, respectively. Results on the thermal constants and lower and upper threshold temperatures of B. fusca can be used to predict the impact of climate change on the distribution and population growth of this pest.

scholarly journals Large increases in adipose triacylglycerol flux in Cushingoid CRH-Tg mice are explained by futile cycling

2013 ◽  
Vol 304 (3) ◽  
pp. E282-E293 ◽  
Author(s):  
Charles Harris ◽  
Donald J. Roohk ◽  
Mark Fitch ◽  
Benjamin M. Boudignon ◽  
Bernard P. Halloran ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Collagen Synthesis ◽  
Muscle Protein ◽  
Subcutaneous Fat ◽  
Skin Thickness ◽  
Breakdown Rate ◽  
Triglyceride Synthesis ◽  
Fat Depots ◽  
Breakdown Rates ◽  
Skin Collagen

Glucocorticoids are extremely effective anti-inflammatory therapies, but their clinical use is limited due to severe side effects, including osteoporosis, muscle wasting, fat redistribution, and skin thinning. Here we use heavy water labeling and mass spectrometry to measure fluxes through metabolic pathways impacted by glucocorticoids. We combine these methods with measurements of body composition in corticotropin-releasing hormone (CRH)-transgenic (Tg)+ mice that have chronically elevated, endogenously produced corticosterone and a phenotype that closely mimics Cushing's disease in humans. CRH-Tg+ mice had increased adipose mass, adipose triglyceride synthesis, and greatly increased triglyceride/fatty acid cycling in subcutaneous and abdominal fat depots and increased de novo lipogenesis in the abdominal depot. In bone, CRH-Tg+ mice had decreased bone mass, absolute collagen synthesis rates, and collagen breakdown rate. In skin, CRH-Tg+ mice had decreased skin thickness and absolute collagen synthesis rates but no decrease in the collagen breakdown rate. In muscle, CRH-Tg+ mice had decreased muscle mass and absolute protein synthesis but no decrease in the protein breakdown rate. We conclude that chronic exposure to endogenous glucocorticoid excess in mice is associated with ongoing decreases in bone collagen, skin collagen, and muscle protein synthesis without compensatory reduction (coupling) of breakdown rates in skin and muscle. Both of these actions contribute to reduced protein pool sizes. We also conclude that increased cycling between triglycerides and free fatty acids occurs in both abdominal and subcutaneous fat depots in CRH-Tg+ mice. CRH-Tg mice have both increased lipolysis and increased triglyceride synthesis in adipose tissue.

scholarly journals Studies on the variation and inheritance of the hard seed content of Renge (Astragalus sileicus L, ).

1963 ◽  
Vol 13 (1) ◽  
pp. 21-24 ◽  
Author(s):  
Katsumi SYAKUDO ◽  
Syutaro KAWABATA ◽  
Motoi MURATA
Keyword(s):  
Hard Seed ◽  
Seed Content

scholarly journals Impact of Constant Versus Fluctuating Temperatures on the Development and Life History Parameters of Aldrichina grahami (Diptera: Calliphoridae)

Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 184 ◽  
Author(s):  
Wei Chen ◽  
Li Yang ◽  
Lipin Ren ◽  
Yanjie Shang ◽  
Shiwen Wang ◽  
...  
Keyword(s):  
Life History ◽  
Ambient Temperature ◽  
Developmental Rate ◽  
Threshold Temperature ◽  
Life History Parameters ◽  
Temperature Regimes ◽  
Cold Tolerant ◽  
Constant Versus ◽  
Forensic Tools ◽  
Fluctuating Temperatures

Necrophagous fly species are commonly used as forensic tools to estimate the minimum postmortem interval (PMImin). Many researchers raised necrophagous flies under constant temperature regimes to collect their developmental data. However, in most forensic cases, the ambient temperature fluctuates. In order to investigate a forensically important fly developmental mode (the Isomegalen diagram, Isomorphen diagram and Thermal summation models) and make comparisons of the developmental rate between constant temperatures and fluctuating temperatures, we used Aldrichina grahami (Diptera: Calliphoridae) to investigate the life history parameters at eight constant temperatures ranging from 8 to 36 °C. We also compared developmental rate of A. grahami in three groups of constant versus fluctuating temperatures: 8 °C vs. 6–12 °C, 12 °C vs. 10–16 °C, and 16 °C vs. 14–20 °C. Our data showed that A. grahami is cold tolerant with a mean (±SE) development threshold temperature (D0) of 3.41 ± 0.48 °C and a thermal summation constant (K) of 8125.2 ± 288.4-degree hours. The three groups subjected to fluctuating temperatures took longer to develop compared to those developing in constant temperatures when simulated in a model. These results not only provide detailed developmental data for the use of A. grahami in the estimation of the PMI, but also indicate that ambient temperature fluctuation must be taken into consideration for the use of all necrophagous fly species.

scholarly journals Regulation of the breakdown rates of biotin-containing proteins in Swiss 3T3-L1 cells

1988 ◽  
Vol 251 (3) ◽  
pp. 749-755 ◽  
Author(s):  
C S Chandler ◽  
F J Ballard
Keyword(s):  
Rate Constants ◽  
Degradation Rate ◽  
Mitochondrial Protein ◽  
Acetyl Coa Carboxylase ◽  
Inhibitory Effects ◽  
Breakdown Rate ◽  
Breakdown Rates ◽  
Lysosomal Proteolysis ◽  
Swiss 3T3 ◽  
Inhibitory Agents

1. Degradation rate constants for individual biotin-labelled proteins were measured in Swiss 3T3-L1 adipocytes that had been incubated with inhibitors of autophagy or of lysosomal proteolysis. 2. Inhibitory effects produced by 10 mM-3-methyladenine and a combination of 5 mM-NH4Cl and leupeptin (50 micrograms/ml) were approximately equal. The inclusion of NH4Cl did not significantly enhance the responses to 3-methyladenine, suggesting that autophagy was already maximally inhibited. 3. The extent of inhibition by 3-methyladenine or by the NH4Cl/leupeptin mixture was similar for the cytosolic enzyme acetyl-CoA carboxylase and for the three mitochondrial carboxylases. This inhibition averaged 50%. The breakdown rate of a more-stable 38 kDa biotin-containing mitochondrial protein was more responsive to the inhibitory agents. These results are best explained by mitochondrial proteolysis occurring via a combination of the degradation of whole mitochondria within autophagic vacuoles, supplemented by the selective intramitochondrial breakdown of more labile proteins. 4. A number of intermediate products in the degradation of biotin-containing proteins were detected. Differences in the patterns of radioactivity between these peptides after incubation of cells in the presence of inhibitors of the breakdown process provided evidence that some peptides were produced before autophagy, others as a result of intralysosomal inhibition, while at least one was associated with intramitochondrial proteolysis.

scholarly journals Skeletal-muscle growth and protein turnover

1975 ◽  
Vol 150 (2) ◽  
pp. 235-243 ◽  
Author(s):  
D J Millward ◽  
P J Garlick ◽  
R J C Stewart ◽  
D O Nnanyelugo ◽  
J C Waterlow
Keyword(s):  
Skeletal Muscle ◽  
Growth Rate ◽  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Growth ◽  
Muscle Size ◽  
Synthesis Rate ◽  
Protein Breakdown ◽  
Breakdown Rate ◽  
Breakdown Rates

Because of turnover, protein synthesis and breakdown can each be involved in the regulation of the growth of tissue protein. To investigate the regulation of skeletal-muscle-protein growth we measured rates of protein synthesis and breakdown in growing rats during development on a good diet, during development on a marginally low-protein diet and during rehabilitation on a good diet after a period of severe protein deficiency. Rates of protein synthesis were measured in vivo with a constant intravenous infusion of [14C]tyrosine. The growth rate of muscle protein was measured and the rate of breakdown calculated as breakdown rate=synthesis rate-growth rate. These measurements showed that during development on a good diet there was a fall with age in the rate of protein synthesis resulting from a fall in capacity (RNA concentration) and activity (synthesis rate per unit of RNA). There was a fall with age in the breakdown rate so that the rate was highest in the weaning rats, with a half-life of 3 days. There was a direct correlation between the fractional growth and breakdown rates. During rehabilitation on the good diet, rapid growth was also accompanied by high rates of protein breakdown. During growth on the inadequate diet protein synthesis rates were lesss than in controls, but growth occurred because of decreased rates of protein breakdown. This compression was not complete, however, since ultimate muscle size was only one-half that of controls. It is suggested that increased rates of protein breakdown are a necessary accompaniment to muscle growth and may result from the way in which myofibrils proliferate.

Hard-seed content of alfalfa grown in Canada

1991 ◽  
Vol 71 (2) ◽  
pp. 437-444 ◽  
Author(s):  
D. T. Fairey ◽  
L. P. Lefkovitch
Keyword(s):  
British Columbia ◽  
Geographic Location ◽  
Viable Seed ◽  
Hard Seed ◽  
Peace River ◽  
Seed Content ◽  
River Region ◽  
Hard Seeds ◽  
Viable Seeds ◽  
Production Areas

The hard-seed content of alfalfa (Medicago spp.) grown in Canada in relation to genotype and geographic location of production was surveyed for the commercial growing regions in Manitoba, Saskatchewan, Alberta and British Columbia. The average hard-seed content of all pedigreed production over a 5-yr period, ranged from 22 to 37% and that in nonpedigreed production was between 14 and 30%. A database of the five widely grown cultivars revealed that the hard-seed content of alfalfa in the most northerly growing areas in the Peace River region of Alberta and British Columbia ranged from 31 to 51%, while hard seed content of alfalfa produced elsewhere varied from 22 to 38%. There was no apparent effect of latitude on the proportion of hard seeds, while there was a small increase for two of the five cultivars in production areas further west. Of particular interest was the trend in viable seed production. There was consistent evidence suggesting that the proportion of viable seeds decreased in production areas further north, but increased in production areas further west. However, the minimum viability was always in excess of 85%. There was no correlation between hard and viable seed. Key words: Medicago spp., alfalfa, lucerne, hard seeds, viable seeds

scholarly journals Metabolism of myosin heavy chain in steady-state chick skeletal muscle cultures

1981 ◽  
Vol 194 (1) ◽  
pp. 241-247 ◽  
Author(s):  
R B Young ◽  
O C Dombroske
Keyword(s):  
Steady State ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Horse Serum ◽  
Absolute Rate ◽  
Direct Proportion ◽  
Breakdown Rate ◽  
Breakdown Rates ◽  
Muscle Cultures ◽  
Chain Synthesis

Synthesis, accumulation and breakdown of the 200000-mol.wt. heavy subunit of myosin were analysed over an 11 day period in muscle cell cultures isolated from the leg muscle of 12-day chick embryos. Muscle cells accumulated myosin heavy chain rapidly from days 2 to 5 and maintained a maximum, constant myosin-heavy-chain concentration between days 7 and 11. Myosin-heavy-chain content and breakdown rate were compared in steady-state muscle cultures grown either in the presence of an optimum batch of horse serum (control) or in the presence of horse serum that had been pre-selected for its ability to inhibit several-fold the rate of synthesis of myosin heavy chain (inhibitory). The quantity of myosin heavy chain in the inhibited cultures was decreased in direct proportion to the decrease in the rate of synthesis of myosin heavy chain; however, the half-lives of myosin heavy chain (control, 17.7h; inhibitory, 17.0h) were virtually identical. In contrast, the absolute rate of breakdown of myosin heavy chain, expressed as molecules/min per nucleus, was approx. 5-fold lower in the inhibited cultures (4.3 × 10(3) molecules/min per nucleus) than in the control cultures (21.7 × 10(3) molecules/min per nucleus). Thus, inhibition of myosin-heavy-chain synthesis in this case was accompanied by diminished myosin-heavy-chain concentration and absolute breakdown rate at the altered steady state, but relative myosin-heavy-chain breakdown rates were unchanged.

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