dormancyrelease

Dormancy release is the physiological transition by which a previously dormant biological state becomes capable of growth and development when environmental conditions become favorable. In plants, the term most often applies to seeds and buds, though microbial dormancy can also be reversed under suitable cues.

In seeds, dormancy release refers to the shift from a dormant state to the ability to germinate. Seeds may exhibit physiological, physical, or morphophysiological dormancy, and breaking it typically requires environmental stimuli such as cold stratification (exposure to low temperatures with moisture), scarification or abrasion of a hard seed coat, or a period of after-ripening during dry storage. Light exposure also influences germination in many species. Hormonal changes underpin this transition: abscisic acid (ABA) generally promotes dormancy, while gibberellins (GA) and other growth signals promote the loss of dormancy and the resumption of germination.

In buds of temperate perennials, dormancy release often involves endodormancy, imposed by winter conditions. Chilling or exposure to prolonged low temperatures accumulates chilling units that eventually permit growth upon the return of warmer temperatures. Some species also require a subsequent warm period or specific thermo-time to complete dormancy release. Molecularly, this process involves shifts in hormone signaling—commonly a reduction in ABA activity and an increase in GA responsiveness—and changes in gene expression related to growth resumption.

Applications and implications of dormancy release are significant in agriculture, horticulture, and conservation. Effective dormancy-breaking treatments can synchronize germination or flowering, improve establishment, and enhance yields, while inappropriate timing can lead to poor performance or failed crops.