Dormancy and the Control of Germination
2012; Linguagem: Inglês
10.1007/978-1-4614-4693-4_6
ISSN0736-6833
AutoresJ. Derek Bewley, Kent J. Bradford, Henk W. M. Hilhorst, Hiroyuki Nonogaki,
Tópico(s)Growth and nutrition in plants
ResumoDormancy is the temporary failure of a seed to complete germination under favorable conditions. It allows for the dispersal of seeds in space and time. There are several types of dormancy, which include physical, mechanical, or chemical inhibition by the covering layers of the embryo, the inability to germinate because of an undifferentiated or immature embryo, and the repression of germination by metabolic restraints. The breaking of dormancy is governed by environmental cues, including temperature, light, nitrate, and some smoke components. This allows seedling establishment during suitable conditions to maximize survival. The breaking of physiological dormancy and the induction of germination are regulated via hormone signaling pathways and mainly through the GA- (gibberellin) and ABA-(abscisic acid) biosynthetic and catabolic pathways. The ABA–GA balance appears to be a central regulatory feature that integrates multiple interactions among environmental cues.
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