scholarly journals Quantifying the sensitivity of barley seed germination to oxygen, abscisic acid, and gibberellin using a population-based threshold model

2008 ◽  
Vol 59 (2) ◽  
pp. 335-347 ◽  
Author(s):  
Kent J. Bradford ◽  
Roberto L. Benech-Arnold ◽  
Daniel Côme ◽  
Françoise Corbineau
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Threshold Model ◽  
Population Based ◽  
Barley Seed

Quantifying the oxygen sensitivity of seed germination using a population-based threshold model

2007 ◽  
Vol 17 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Kent J. Bradford ◽  
Daniel Côme ◽  
Françoise Corbineau
Keyword(s):  
Standard Deviation ◽  
Seed Germination ◽  
Time Constant ◽  
Threshold Model ◽  
Seed Priming ◽  
Population Based ◽  
Physiological Status ◽  
Wide Range ◽  
Time Courses ◽  
Germination Timing

AbstractSeeds vary widely in the sensitivity of germination to oxygen (O2) partial pressure, depending upon the species, temperature, dormancy state and physiological status of the seeds. Most analyses of the O2 sensitivity of germination have focused on final germination percentages and estimated the O2 percentage in air that is required to reduce germination to a given percentage (usually 50%). In contrast, we have applied a population-based threshold model utilizing time courses of germination to quantify three parameters related to seed germination sensitivity to O2 availability: the median base (or threshold) O2 percentage, the standard deviation of O2 thresholds among seeds in the population, and an oxygen–time constant that relates O2 percentage to germination timing. The model fits germination responses accurately across a wide range of O2 concentrations. The response to O2 was logarithmic in all cases, with the O2 percentage required for 50% germination ranging from 21% to as low as 0.005%, depending upon the species, the temperature and the seed dormancy level. Modelling indicated that some seeds can adapt to low O2 percentages and shift their thresholds to lower values over time. Lower temperatures decreased the minimum O2 threshold, as did after-ripening. Seed priming generally reduced the oxygen–time constant and increased the standard deviation of germination responses, but had relatively little effect on the O2 sensitivity per se. The population-based threshold model can be used to quantify the O2 sensitivity of seed germination and to predict germination rates and percentages when O2 availability is limiting.

scholarly journals Inhibition ofα-Amylase Induction in Barley Seed and the Induction of Stomatal Pore Closure by Artificial Abscisic Acid Analogs (RCA Series)

1992 ◽  
Vol 56 (12) ◽  
pp. 2089-2090 ◽  
Author(s):  
Tadao Asami ◽  
Bum-Tae Kim ◽  
Kensuke Morita ◽  
Tomoko Abe ◽  
Chang-Ho Soh ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Barley Seed ◽  
Pore Closure ◽  
Amylase Induction

Abscisic acid controls embryo growth potential and endosperm cap weakening during coffee (Coffea arabica cv. Rubi) seed germination

Planta ◽  
2004 ◽  
Vol 220 (2) ◽  
pp. 251-261 ◽  
Author(s):  
E. A. Amaral da Silva ◽  
Peter E. Toorop ◽  
Adriaan C. van Aelst ◽  
Henk W. M. Hilhorst
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Coffea Arabica ◽  
Growth Potential

Abstract P036: Parathyroid Hormone is Associated with All-Cause and Cardiovascular Mortality: The Hoorn Study

Circulation ◽  
2013 ◽  
Vol 127 (suppl_12) ◽  
Author(s):  
Adriana J van Ballegooijen ◽  
Ilse Reinders ◽  
Marjolein Visser ◽  
Jacqueline M Dekker ◽  
Giel Nijpels ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Cox Regression ◽  
Threshold Model ◽  
Older Men ◽  
Population Based ◽  
Survival Curves ◽  
Men And Women ◽  
Serum Pth ◽  
Older Men And Women ◽  
Cvd Mortality

Introduction Higher parathyroid hormone (PTH) concentrations have been associated with increased cardiovascular disease (CVD) mortality, although data in the general population are scarce. Hypothesis We hypothesize that higher serum PTH concentrations are associated with all-cause and CVD mortality in a prospective, population-based cohort of older men and women. Methods We included 633 participants of the Hoorn Study, a population-based cohort with oversampling of subjects with impaired glucose regulation; mean age 70.1±6.6 years, 50.7% female. Serum intact PTH concentrations were measured using a 2-site immunoassay. Outcomes were all-cause and CVD mortality based on clinical files and coded according to the ICD-9. We used Cox-regression to estimate survival curves and hazard ratios (HR 95% CI) for all-cause and CVD mortality adjusted for potential confounders using season-specific PTH quartiles. Results During a median follow-up of 7.8 years, 112 participants died, of which 26 deaths (23%) were due to CVD. Survival curves showed an impaired survival for all-cause (Log-rank p=0.054) and CVD mortality (Log-rank p=0.022) for people in the highest PTH quartile (Figure 1). In a multivariate model adjusted for age, sex, smoking, education level, BMI, glucose status, systolic blood pressure, anti-hypertensive drug use, the highest PTH quartile was associated with higher all-cause mortality; HR 1.98 (1.08, 3.64). Kidney function (estimated glomerular filtration rate and micro-albuminuria) attenuated the PTH risk association, but risk persisted; HR 1.93 (95% CI 1.04, 3.58). The results for CVD mortality showed a similar pattern, although the association was only significant in a threshold model (Quartile 4 vs. Quartile 1-3) HR 2.56 (1.11, 5.94). Conclusion In conclusion, among older men and women, higher PTH concentrations are associated with higher mortality risk. We suggest to evaluate whether individuals with high PTH concentrations benefit from therapeutic approaches targeted to decrease PTH concentrations.

scholarly journals Effects of hormonal priming on seed germination of pigeon pea under cadmium stress

2015 ◽  
Vol 87 (3) ◽  
pp. 1847-1852 ◽  
Author(s):  
LARISSA C. SNEIDERIS ◽  
MARINA A. GAVASSI ◽  
MARCELO L. CAMPOS ◽  
VICTOR D'AMICO-DAMIÃO ◽  
ROGÉRIO F. CARVALHO
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Efficient Method ◽  
Physiological Responses ◽  
Cadmium Stress ◽  
Pigeon Pea ◽  
Metal Stress ◽  
Hormonal Priming

In this work we investigated whether priming with auxin, cytokinin, gibberellin, abscisic acid and ethylene, alters the physiological responses of seeds of pigeon pea germinated under water and cadmium stress. Seeds treated with water or non-treated seeds were used as control. Although compared to non-treated seeds we found that the hormone treatments improve the germination of pigeon pea under cadmium stress, however, these treatments did not differ from water. However, we also observed a trend of tolerance to the effects of cadmium in the presence of ethylene, suggesting that the use of this hormone may be an efficient method to overcome seed germination under metal stress.

Spatio-temporal profiling and degradation of α-amylase isozymes during barley seed germination

FEBS Journal ◽  
2007 ◽  
Vol 274 (10) ◽  
pp. 2552-2565 ◽  
Author(s):  
Kristian S. Bak-Jensen ◽  
Sabrina Laugesen ◽  
Ole Østergaard ◽  
Christine Finnie ◽  
Peter Roepstorff ◽  
...  
Keyword(s):  
Seed Germination ◽  
Barley Seed ◽  
Spatio Temporal
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