BIOL 260 Lecture Notes - Lecture 19: Seed Dormancy, Chlorophyll, Water Potential
Document Summary
Discuss the role of gibberellin and abscisic acid in regulating seed germination. Discuss how abscisic acid acts to regulate water loss in plants. Describe the role of cytokinins in controlling leaf senescence. Describe the role of ethylene in fruit ripening. Describe the hypersensitive response (hr) and contrast it with systemic acquired resistance (sar) Role of gibberellin and abscisic acid in regulating seed germination. Tissue age: newly developing tissue vs. senescent tissue. Different hormones work together with each other. Parthenocarpy (fruits that are developed without seeds e. g. grapes, watermelons, etc. ) Aleurone: source of the alpha-amylase enzyme used to break down starch into sugars. Endosperm: surrounds the embryo and stores energy in the form of starch. Embryo: multicellular organism before it emerges from the seed; source of gibberellins. Seed coat: semi-hard covering that creates a barrier between environmental factors and the embryo. Water is an important signal to trigger germination (same with phytochrome ratios)
