|WILLICK, IAN - University Of Saskatchewan|
|DUMAN, JOHN - University Of Notre Dame|
|NEWTON, SAMUEL - University Of South Dakota|
Submitted to: Springer Verlag
Publication Type: Book / Chapter
Publication Acceptance Date: 3/28/2018
Publication Date: N/A
Technical Abstract: Proteins that determine the temperature at which ice crystals will form in water-based solutions in cells and tissues, that bind to growing ice crystals, thus affecting their size, and that impact ice re-crystallization have been widely-documented and studied in many plant, bacterial, fungal, insect, and other animal species. The properties of these proteins have led them to be referred to as antifreeze proteins (AFPs), thermal hysteresis (TH) proteins, ice-binding proteins, and re-crystallization inhibiting (RI) proteins. In contrast to AFPs identified in insect and animals, the TH activity of plant AFPs (IBPs) is relatively weak. For this reason, their ice-binding and RI properties have been suggested to be more relevant to their role in preventing freeze injury in plants. Both ice-binding and RI activity would prevent the formation of large ice crystals that could potentially cause mechanical disruption of cells and tissues within the plant. The relatively low TH activity of plant AFPs (IBPs), however, has been solely demonstrated in vitro in plant or protein (purified and non-purified) extracts. This approach does not consider, however, the presence of a cell wall and the existing pore structure of any specific cell wall. Therefore, more studies on TH activity of plant AFPs (IBPs) should be conducted in nanopore systems that simulate cell wall structure to gain a more comprehensive understanding of the potential role of the TH activity of plant AFPs in ice formation and propagation, especially since these proteins are secreted into the apoplast.