The regulatory roles of let-7 in embryo dormancy in mice

2014 ◽  
Author(s):  
Weimin Liu ◽  
Ronald T K Pang ◽  
William S B Yeung
Keyword(s):  
Embryo Dormancy

Embryo dormancy responses to temperature in capeweed (Arctotheca calendula) seeds

2002 ◽  
Vol 12 (3) ◽  
pp. 181-191 ◽  
Author(s):  
Amanda J. Ellery
Keyword(s):  
Soil Temperature ◽  
Water Potential ◽  
Low Temperatures ◽  
Seasonal Changes ◽  
Temperature Fluctuation ◽  
Soil Surface ◽  
Seed Collection ◽  
Embryo Dormancy ◽  
Response To Temperature ◽  
Dormancy Cycles

Changes in embryo dormancy of capeweed [Arctotheca calendula (L.) Levyns.] seeds in response to temperature were investigated to determine the nature of seasonal dormancy cycles. Primary embryo dormancy persisted for 2–3 months after seed collection and was then rapidly relieved when seeds were maintained at temperatures simulating summer soil surface temperatures. Embryo dormancy was also rapidly relieved in seeds maintained at constant temperatures, indicating that a daily temperature fluctuation was not necessary for the relief of embryo dormancy in capeweed. Dormancy relief was maximal at 40°C. Secondary dormancy was induced when seeds were maintained at low temperatures and a water potential of –1.5 MPa, suggesting that the onset of winter may postpone germination until a subsequent autumn. These results indicate that the dormancy cycles observed in capeweed seeds maintained on the soil surface are probably driven by seasonal changes in soil temperature.

The Development of Embryo Dormancy and Testa-imposed Dormancy during Seed Ontogeny in the Genus Acer

1990 ◽  
Vol 136 (6) ◽  
pp. 746-749 ◽  
Author(s):  
N.J. Pinfield ◽  
S.A. Bazaid ◽  
V.E.E. Gwarazimba
Keyword(s):  
Embryo Dormancy

scholarly journals Role of Endosperm in Releasing Embryo Dormancy of 'Campbell Early' Grape Seed.

1998 ◽  
Vol 67 (5) ◽  
pp. 728-733
Author(s):  
Jun Song Liu ◽  
Shousaku Horiuchi ◽  
Tsuneo Ogata ◽  
Shuji Shiozaki ◽  
Ryosuke Mochioka
Keyword(s):  
Grape Seed ◽  
Embryo Dormancy

Structural aspects of dormancy in quinoa (Chenopodium quinoa): importance and possible action mechanisms of the seed coat

2015 ◽  
Vol 25 (3) ◽  
pp. 267-275 ◽  
Author(s):  
Diana Ceccato ◽  
Daniel Bertero ◽  
Diego Batlla ◽  
Beatriz Galati
Keyword(s):  
Seed Coat ◽  
Chenopodium Quinoa ◽  
Sowing Date ◽  
Sources Of Resistance ◽  
Action Mechanisms ◽  
Sowing Dates ◽  
Embryo Dormancy ◽  
Different Temperatures ◽  
Seed Coats ◽  
Structural Aspects

AbstractTwo possible sources of resistance to pre-harvest sprouting were evaluated in quinoa. They showed dormancy at harvest and significant variations in dormancy level in response to environmental conditions experienced during seed development. The aims of this work were to evaluate the importance of seed coats in the regulation of dormancy in this species, to investigate possible mechanisms of action and to assess association of seed coat properties with changes in dormancy level caused by the environment. Accessions Chadmo and 2-Want were grown under field conditions on different sowing dates during 2 years. Seed coats were manipulated and seed germination was evaluated at different temperatures. Seed coat perforation before incubation led to faster dormancy loss in both accessions. This effect decreased with delayed sowing date, and seeds expressed a level of dormancy not imposed by coats. This suggests the presence of embryo dormancy in the genus Chenopodium. Seeds of the accession 2-Want had a significantly thinner seed coat at later sowing dates, associated with a decreasing coat-imposed dormancy, but this pattern was not detected in Chadmo. The seed coat acts as a barrier to the release of endogenous abscisic acid (ABA) in quinoa, suggested by the increase in germination and a higher amount of ABA leached from perforated seeds. ABA is able to leach from seeds with an intact seed coat, suggesting that differences in seed coat thickness may allow the leakage of different amounts of ABA. This mechanism may contribute to the observed differences in dormancy level, either between sowing dates or between accessions.

scholarly journals Involvement of Endogenous Abscisic Acid in Onset and Release of Helianthus annuus Embryo Dormancy

1990 ◽  
Vol 92 (4) ◽  
pp. 1164-1168 ◽  
Author(s):  
Marie-Thérèse Le Page-Degivry ◽  
Philippe Barthe ◽  
Ginette Garello
Keyword(s):  
Abscisic Acid ◽  
Helianthus Annuus ◽  
Endogenous Abscisic Acid ◽  
Embryo Dormancy

Dormancy of apple embryos. Are starch and reserve protein changes related to dormancy breaking?

1984 ◽  
Vol 62 (11) ◽  
pp. 2308-2315 ◽  
Author(s):  
Michelle Bouvier-Durand ◽  
Alina Dawidowicz-Grzegorzewska ◽  
Claudine Thévenot ◽  
Daniel Come
Keyword(s):  
Cold Treatment ◽  
Moderate Temperature ◽  
The Other ◽  
Cold Stratification ◽  
Dormancy Release ◽  
Dormancy Breaking ◽  
Germination Process ◽  
Embryo Dormancy ◽  
Reserve Protein ◽  
Apple Seeds

During cold stratification of apple seeds both dormancy removal and initiation of the germination process occur. To characterize these two processes and to dissociate them from each other, two different cold treatments were used. One of them (cold treatment within the fruits) excluded the germination process, the other corresponded to classical stratification. Control treatments at moderate temperature were also applied. Starch accumulated in the radicle during breaking of embryo dormancy by stratification, whereas it disappeared when dormancy was broken inside the fruits. The comparison of starch changes at 0 and at 20 °C also showed that these changes cannot be related to dormancy release. Moreover, no proteolysis occurred whether dormancy was broken or not. Proteolysis observed during stratification of the embryos seemed to be linked to their imbibition (the first step of the germination). These data refute previous observations on this problem; they demonstrate that neither starch variations nor reserve protein changes can be related to breaking of embryo dormancy.

Abscisic acid and the regulation of embryo dormancy in the genus Acer

1990 ◽  
Vol 6 (1) ◽  
pp. 79-85 ◽  
Author(s):  
N. J. Pinfield ◽  
P. A. Stutchbury ◽  
S. A. Bazaid ◽  
V. E. E. Gwarazimba
Keyword(s):  
Abscisic Acid ◽  
Embryo Dormancy

Seed Dormancy and Adaptive Seedling Emergence Timing in Giant Ragweed (Ambrosia trifida)

Weed Science ◽  
2012 ◽  
Vol 60 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Brian J. Schutte ◽  
Emilie E. Regnier ◽  
S. Kent Harrison
Keyword(s):  
Seedling Emergence ◽  
Early Spring ◽  
Soil Conditions ◽  
Inhibitory Influence ◽  
Burial Site ◽  
Crop Fields ◽  
Giant Ragweed ◽  
Physiological Dormancy ◽  
Embryo Dormancy ◽  
Time Required

Giant ragweed germination is delayed by both a physiological dormancy of the embryo (embryo dormancy) and an inhibitory influence of embryo-covering structures (covering structure-enforced [CSE] dormancy). To clarify the roles of embryo and CSE dormancy in giant ragweed seedling emergence timing, we conducted two experiments to address the following objectives: (1) determine changes in germinability for giant ragweed dispersal units (hereafter “involucres”) and their components under natural burial conditions, and (2) compare embryo and CSE dormancy alleviation and emergence periodicity between successional and agricultural populations. In Experiment 1, involucres were buried in crop fields at Columbus, OH, periodically excavated, and brought to the laboratory for dissection. Involucres, achenes, and embryos were then subjected to germination assays at 20 C. In Experiment 2, temporal patterns of seedling emergence were determined at a common burial site. Reductions in embryo and CSE dormancy were compared with controlled-environment stratification followed by germination assays at 12 and 20 C, temperatures representative of soil conditions in spring and summer. Results indicated that overwinter dormancy loss involved sequential reductions in embryo and CSE dormancy. CSE dormancy, which may limit potential for fatal germination during fall, was caused by the pericarp and/or embryo-covering structures within the pericarp. In Experiment 2, successional populations emerged synchronously in early spring, whereas agricultural populations emerged throughout the growing season. Levels of embryo dormancy were greater in the agricultural populations than the successional populations, but CSE dormancy levels were similar among populations. In 12 C germination assays, embryo dormancy levels were positively correlated with time required to reach 95% cumulative emergence (run 1:r= 0.81, P = 0.03; run 2:r= 0.76, P = 0.05). These results suggest that late-season emergence in giant ragweed involves high levels of embryo dormancy that prevent germination at low temperatures in spring.

Sign in / Sign up

Export Citation Format

Share Document