Seed dormancy and germination

Abstract

Seed dormancy allows seeds to overcome periods that are unfavourable for seedling established and is therefore important for plant ecology and agriculture. Several processes are known to be involved in the induction of dormancy and in the switch from the dormant to the germinating state. The role of plant hormones, the different tissues and genes involved, including newly identified genes in dormancy and germination are described in this chapter, as well as the use transcriptome, proteome and metabolome analyses to study these mechanistically not well understood processes.

Figure 1.

Schematic presentation of processes controlling seed dormancy and germination in an Arabidopsis seed. The Arabidopsis seed is characterized by the embryo with two cotyledons and a single cell layer endosperm. Germination promoting (green arrows) and inhibiting factors (red arrows) are indicated.

Figure 2.

Arabidopsis seed germination. A mature Arabidopsis seed can be either dormant or non-dormant. A dormant seed will not germinate when it will be exposed to the right environmental conditions (light and water). Seed dormancy can be broken by dry storage or by a cold imbibition (stratification). Seed germination in Arabidopsis is two-step: testa rupture followed by endosperm rupture.