Category Archives: Plant Physiology
Was doing a discussing as to why most plants cannot survive the winter. No sunlight, too cold – water freeze in the vascular system, leaves get damage from ice crystals. A hand shot up and asked, “What about evergreen trees?”
An excellent question.
Evergreen trees will have to photosynthesize. So they should have a suite of antifreeze proteins much like those found in fish.
Quick google search turns out these results:
Griffith and Yaish 2004 Antifreeze proteins in overwintering plants: a tale of two activities Trends in Plant Science 9(8): 399-405
Abstract from ncbi
Antifreeze proteins are found in a wide range of overwintering plants where they inhibit the growth and recrystallization of ice that forms in intercellular spaces. Unlike antifreeze proteins found in fish and insects, plant antifreeze proteins have multiple, hydrophilic ice-binding domains. Surprisingly, antifreeze proteins from plants are homologous to pathogenesis-related proteins and also provide protection against psychrophilic pathogens. In winter rye (Secale cereale), antifreeze proteins accumulate in response to cold, short daylength, dehydration and ethylene, but not pathogens. Transferring single genes encoding antifreeze proteins to freezing-sensitive plants lowered their freezing temperatures by approximately 1 degrees C. Genes encoding dual-function plant antifreeze proteins are excellent models for use in evolutionary studies to determine how genes acquire new expression patterns and how proteins acquire new activities.
Good resource on photosynthesis. Excellent drawings and easy to understand notes.
From FT Exploring – Photosynthesis pages
This article by K.S. Gould, New Zealand, highlights the diverse role of anthocyanins in plant physiology.
Carl Zimmer’s blog, The Loom, also has a nice write up of the age old question, ‘Why do leaves turn yellow?’
K.S. Gould 2004 Nature’s Swiss Army Knife Journal of Biomedicine and Biotechnology
Volume 2004 (2004), Issue 5, Pages 314-320