Dormancy Research Papers - Academia.edu (original) (raw)

Physiological dormancy of scarified seeds of Townsville stylo (Stylosanthes humilis HBK) was released by acidic aluminium (Al3+) solution. Antiethylenic substances inhibited germination of low-pH-stimulated dormant seeds, with a... more

Physiological dormancy of scarified seeds of Townsville stylo (Stylosanthes humilis HBK) was released by acidic aluminium (Al3+) solution. Antiethylenic substances inhibited germination of low-pH-stimulated dormant seeds, with a correspondingly low ethylene production and low activity of 1-aminocyclopropane-1-carboxylate (ACC) oxidase in seeds. On the other hand, antiethylenic substances did not decrease the germination of Al3+-stimulated seeds, but ACC oxidase activity and ethylene production by the seeds was decreased to a large extent. These data provide evidence that dormancy breakage by Al3+ differs from that caused by low pH and is not associated with ethylene production. Similarly to Al3+ action, methyl viologen (MV), a reactive oxygen species-generating compound, broke dormancy of Townsville stylo seeds. Sodium selenate and N-acetyl cysteine, antioxidant compounds, largely decreased germination of MV- and Al3+-stimulated dormant seeds. Altogether these data point to oxidativ...

Breast cancer remains the main cause of cancer-related mortality for women worldwide. Main cause of death is the development of therapy-resistant metastases. Relapses occur with a bimodal temporal distribution, with a first peak at 1-2... more

Breast cancer remains the main cause of cancer-related mortality for women worldwide. Main cause of death is the development of therapy-resistant metastases. Relapses occur with a bimodal temporal distribution, with a first peak at 1-2 years after initial therapy and a second peak 2-3 years later. This discontinuous growth kinetics is consistent with the notion that disseminated cancer cells can remain dormant over a prolonged period of time before resuming growth. How cancer cells enter, sustain and exit dormancy, are unanswered questions with relevance to cancer biology, monitoring and therapy. Investigating mechanisms of breast cancer dormancy remains challenging, as in patients the condition is elusive and experimentally there are only a few models that recapitulate the clinical condition. Thus, developing new models to identify clinically relevant mechanisms and candidate therapeutic targets may open new avenues for novel therapies to induce and prolong dormancy. We have observed that cells surviving chemotherapy can enter a state of immunological dormancy. Using this model, we identified IRF-7/Interferon type I/IFNRA as signaling axis essential for this effect. Here we will review concepts and recent developments in cancer metastasis and dormancy with emphasis on breast cancer, and elaborate strategies to exploit them therapeutically.

All communities are dominated by a few species that account for most of the biomass and carbon cycling. On the other hand, a large number of species are represented by only a few individuals. In the case of bacteria, these rare species... more

All communities are dominated by a few species that account for most of the biomass and carbon cycling. On the other hand, a large number of species are represented by only a few individuals. In the case of bacteria, these rare species were until recently invisible. Owing to their low numbers, conventional molecular techniques could not retrieve them. Isolation in pure culture was the only way to identify some of them, but current culturing techniques are unable to isolate most of the bacteria in nature. The recent development of fast and cheap high-throughput sequencing has begun to allow access to the rare species. In the case of bacteria, the exploration of this rare biosphere has several points of interest. First, it will eventually produce a reasonable estimate of the total number of bacterial taxa in the oceans; right now, we do not even know the right order of magnitude. Second, it will answer the question of whether “everything is everywhere.” Third, it will require hypothes...

The timing of nitrogen (N) fertilizer application may influence germination, emergence, and competitiveness of weeds. Research was conducted to determine the influence of total inorganic soil N (Nit) on the germination, emergence, and... more

The timing of nitrogen (N) fertilizer application may influence germination, emergence, and competitiveness of weeds. Research was conducted to determine the influence of total inorganic soil N (Nit) on the germination, emergence, and growth of five weed species. In a greenhouse experiment, seed of five weed species were exposed to four levels of N, and seed germination was measured. In the field, urea ammonium nitrate (UAN 28%) was applied at multiple rates at three spring timings, and Nit, weed emergence, and growth were measured for 21 to 35 d after application (DAA). Germination of the four dicotyledonous and single grass species was not stimulated by 450 ppmw of N compared with the untreated control. In the field, Nitof 112 or 168 kg N ha−1, measured at 7 and 21 DAA, was always greater than Nitin the untreated control. The duration of the available N pulse in the upper 8 cm of soil was dependent on N application rate and timing. At 8 to 16 cm of soil depth, Nitwas greater when ...

Garlic (Allium sativum L.) is an agricultural commodity which is widely consumed by the community. The obstacle experienced in cultivation is that a relatively long dormancy period of about 6-7 months. The... more

Garlic (Allium sativum L.) is an agricultural commodity which is widely consumed by the community. The obstacle experienced in cultivation is that a relatively long dormancy period of about 6-7 months. The dormancy of garlic seeds occurs because the embryo has not yet been fully formed, and the growth hormone and inhibitory hormone are not balanced. The methods used to break dormancy and accelerate germination are by using corona incandescent plasma radiation and storagetemperature. The research utilized factorial Completely Randomized Design (CRD), consisting of six treatments with five replications. The first factor was the corona incandescent plasma radiation carried out on the garlic seeds ‘Lumbu Kuning’ variety with time duration of 0, 15, and 30 minutes. The second factor was storage temperature comprising of room temperature and cold temperature of 7oC stored for 30 days. Viability parameters observed are germination percentage dan the length of sprouts. The data were analyzed by using ANOVA followed by the DMRT test at the 95% confidence level. The results showed that corona incandescent plasma radiation influenced the germination percentage using plasma radiation for 15- 30 minutes.

A propagação de Acnistus arborescens (fruto-do-sabiá) usualmente é feita através de estacas, devido a baixa taxa de germinação de suas sementes. O objetivo deste trabalho foi estudar o efeito da temperatura e do estimulante nitrato de... more

A propagação de Acnistus arborescens (fruto-do-sabiá) usualmente é feita através de estacas,
devido a baixa taxa de germinação de suas sementes. O objetivo deste trabalho foi estudar o efeito
da temperatura e do estimulante nitrato de potássio (KNO3) na germinação do fruto-do-sabiá.
O experimento foi realizado utilizando quatro regimes de temperatura (20, 25, 30 e 20-30 °C),
com e sem nitrato de potássio, em delineamento inteiramente casualizado com quatro repetições
de 50 sementes cada. Foram avaliados a porcentagem, o índice de velocidade e o tempo médio
de germinação. Nas temperaturas constantes, o KNO3 favoreceu a germinação, sendo as maiores
porcentagens (>68%) obtidas nas temperaturas de 20 °C e 25 °C. A temperatura alternada de
20-30 °C aumentou a porcentagem de germinação, sem a adição de KNO3, portanto além da
propagação vegetativa. A produção de mudas a partir de sementes é viável.

— The aim of this study was to elucidate the effect of hydrogen cyanamide (HC) and thiourea on dormancy release and carbohydrates metabolism in floral, vegetative buds and bark tissues of pear (Pyrus pyrifolia Nakai) cultivar 'Wonhwang'.... more

— The aim of this study was to elucidate the effect of hydrogen cyanamide (HC) and thiourea on dormancy release and carbohydrates metabolism in floral, vegetative buds and bark tissues of pear (Pyrus pyrifolia Nakai) cultivar 'Wonhwang'. Selected cutting were immersed in appropriate solutions of HC, thiourea and dH2O as a control while cultured in forcing condition for 5 weeks. Our results showed that both the treatments were more effective in dormancy release of both floral and vegetative buds as compared to control. However, the cuttings treated with HC started the floral and vegetative budbreak after 5 and 7 days of treatment followed by thiourea 7 and 9 days and control 13 and 13 days respectively. 50% floral budbreak was observed after 18, 22 and 30 days of treatment during forcing, on cutting treated with HC, thiourea and control while 50% vegetative budbreak was noted on cuttings treated with HC and thiourea after 22 and 26 days treatment during forcing. For control, 49.3% vegetative budbreak was observed after five week during forcing. Mean time to budbreak (MTB) for both floral and vegetative buds was less for HC followed by thiourea and control. HC and thiourea application caused an abrupt increase in starch hydrolysis and a transient accumulation of soluble sugars in buds and bark tissues during the first five and ten days after treatment. These variations, which happened shortly after HC and thiourea application, seemed to be linked with a process leading to endo-dormancy release. In fact, as budbreak started, we observed a rapid decline in sucrose, glucose and fructose concentrations in all treated tissue, while these concentrations remained high in untreated tissues and then decreased when starch concentration started to increase. Sorbitol concentration increased in treated and untreated floral buds up to 20 days in the same trend and then decreased. Our data suggest that the difference in the timing of soluble sugars accumulation/consumption process between HC, thiourea applications and control cuttings may account for the differences in the timing of growth resumption and budbreak growth.