Which factor is critical for seed germination promoted by gibberellins?

Water availability is critical for seed germination promoted by gibberellins because gibberellins are plant hormones that play a significant role in the germination process. Seeds typically remain in a dormant state until they absorb enough water, triggering metabolic processes essential for germination. When water is available, it activates enzymes that begin the conversion of stored food reserves into sugars, which provide energy for the developing plant.

In the presence of gibberellins, this process is further enhanced, as the hormone promotes the synthesis of these enzymes and stimulates the growth processes necessary for breaking the seed coat, allowing the embryo to emerge. Without adequate water, the activation of these processes is severely limited, preventing successful germination regardless of other environmental factors.

While temperature, light exposure, and soil composition can influence germination, they do not have the same direct and pivotal role as water does in the initial activation of the biological processes necessary for a seed to germinate. Water is the essential component that initiates these biochemical reactions, making it the most critical factor facilitated by gibberellins.