Final answer:
In plants, seed dormancy can be broken by cold temperatures, which are essential for the accumulation of chill units, allowing seeds to germinate in favorable conditions. Abscisic acid (ABA) also induces dormancy, which is overcome by temperature changes, indicating the crucial role of temperature as a cue in plant development and seasonal synchronization.
Step-by-step explanation:
Understanding Seed Dormancy and Temperature
The dormancy mechanism in seeds affected by a change in temperature is a crucial adaptive feature for species in temperate climates. This mechanism ensures that germination occurs only when environmental conditions are favorable, thereby enhancing the survival rates of new plants. The hormone abscisic acid (ABA) plays a major role in inducing dormancy by blocking germination and encouraging the development of storage proteins and winter buds. In order for dormancy to be broken, a sufficient accumulation of chill units, which require cold temperatures typically below 10°C, is necessary. Once enough chill units are gathered, metabolic activity is promoted by the gradual increase in temperatures.
Additionally, cold treatments are necessary for breaking the dormancy of shoot apical meristems or buds, a tactic home gardeners often utilize to force early flowering in plants. This is also why certain plants cannot grow in warmer climates as they may not receive enough cold exposure to exit dormancy. Similarly, daily and seasonal responses can also influence plant behaviors such as leaf opening or shedding, triggering dormancy in anticipation of winter conditions.
Overall, these temperature cues are essential for the synchronized growth and development of plants with the seasons, ensuring that activities such as leaf out and flowering coincide with optimal climate conditions.