BIOL 1902 Lecture Notes - Lecture 9: Abies Balsamea, Antifreeze Protein, Acer Rubrum
28 Feb 2016
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Document Summary
Excess water withdrawn & evaporates from leaves & twigs. Water drawn out of cells, which increases solute concentration. Protective sugars added to cells increasing solute concentration. Cell membranes become more flexible (unsaturated fatty acids added) Antifreeze proteins to suppress ice formation & proteins to resist dehydration. 1st stage of acclimation triggered by change in photoperiod (daylight to darkness ratio: phytochromes = light-sensitive photopigments. Make plant more responsive to low temperatures. 2nd stage triggered by cold (not sub-zero (10 - 0 c)) temperatures. Skunk cabbage has unusual adaptation for the cold: enable chlorophyll to use sun"s energy to create heat, not photosynthesize, turns up the heat, some insects inside of it taking advantage of the heat. Conifers retain their leaves so size & shape = very important: leaf surface area = small close stomata, thick cuticles, hairs on underside of leaves. Rock polypody = evergreen (green all year round) fern.
