How might day length, phytochrome, and PGRs interact in the germination of seeds planted just below the soil surface? Deciduous trees, such as oaks and maples, lose their leaves in the fall. Describe...

How might day length, phytochrome, and PGRs interact in the germination of seeds planted just below the soil surface? Deciduous trees, such as oaks and maples, lose their leaves in the fall. Describe how PGRs and environmental stimuli might bring about this response. Plant development appears to be much more closely linked to environmental cues than animal development is. Explain how this adaptation would enhance survival of plants.