Author
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Ehler, Linda |
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Herman, Eliot |
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Submitted to: BARC Poster Day
Publication Type: Abstract Only Publication Acceptance Date: 3/10/2002 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Adverse environmental effects such as freezing temperatures periodically cause significant losses in crop productivity and can be devastating in certain years. Some varieties of wheat (Triticum aestivum) can acclimate to survive below freezing temperatures after a period of cold adaptation, which is critical for survival of the wheat crown meristem. As temperatures decrease below freezing, ice typically forms in the intercellular spaces of plant tissues. Formation of intercellular ice results in a decrease in water potential outside a cell, with the result that there may be a net movement of unfrozen water from inside to outside the cell. This freezing induced dehydration may result in membrane injury and cell death. We reasoned that active control of water flow between the intra- and extracellular spaces may be crucial for survival during freezing. Aquaporins located in the plasma membrane act as water channels, altering the flow of water across the membrane, and the activity of some aquaporins can be regulated by phosphorylation. We screened cDNA clones from a library of cold adapted wheat crowns treated with subzero temperature and identified two different wheat PIP clones which were highly likely to be aquaporins based on sequence similarity. The mRNA expression for one of these clones vigorously responded to cold adaptation at 4C and exposure to freezing at 4C with increased transcript abundance; this response appeared to be localized to crown tissue. The other PIP clone was not localized to crown tissue and did not respond to cold. |
