ARS | Publication request: WINTER RYE ANTIFREEZE PROTEINS ARE NOT CRYOPROTECTIVE, RATHER THEY MODIFY THE GROWTH OF ICE IN PLANTA

Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: July 1, 2003
Publication Date: July 15, 2003
Citation: Griffith, M., Lumb, C., Wiseman, S., Johnson, R., Wisniewski, M.E., Loewen, M. 2003. Winter rye antifreeze proteins are not cryoprotective, rather they modify the growth of ice in planta. Acta Horticulturae. 618 (2003) pg. 31-37.

Technical Abstract: Antifreeze proteins (AFPs) bind to the surface of ice and modify its growth. In overwintering plants, AFPs accumulate in the apoplast where ice forms during freezing, suggesting that their major function is to modify the growth of ice. However, AFPs in other overwintering organisms are reported to play a cryoprotective role through interactions with proteins and membranes. To better understand the role of AFPs, we examined their ability to protect the activity of rabbit lactate dehydrogenase (LDH) and volume of spinach thylakoids subjected to freeze-thaw cycles. Winter rye AFPs were added to solutions of LDH, which were then frozen and thawed and LDH was assayed for activity. In these experiments, LDH activity was higher in the presence of rye AFPs, but the protection was no greater than observed in the presence of bovine serum albumin.