Author
Wisniewski, Michael | |
WILLICK, IAN - University Of Saskatchewan | |
GUSTA, LAWRENCE - University Of Saskatchewan |
Submitted to: Plant Stress Physiology
Publication Type: Book / Chapter Publication Acceptance Date: 3/6/2016 Publication Date: 8/12/2016 Citation: Wisniewski, M.E., Willick, I., Gusta, L. 2016. Freeze tolerance and avoidance in plants. In: Shabala, S., editor. Plant Stress Physiology. 2nd edition. Boston, MA:CAB International. p. 279-299. Interpretive Summary: Technical Abstract: Cold acclimation is a multigenic, quantitative trait that involves biochemical and structural changes that effect the physiology of a plant. Mechanisms associated with freeze tolerance or freeze avoidance develop and are lost on an annual cycle. When conducting studies to characterize and determine the underlying mechansisms for freezing tolerance, it is essential to take into account that the type and form of freezing injury varies with the species and its degree of freezing tolerance and/or ability to avoid freezing. Several different patterns of freezing injury can be manifested depending on tissue water content, plant structure and architecture, degree of supercooling, the ability to resist photoinhibition, the ability to generate new roots, etc. Some cells are injured by the mechanical force of growing ice crystals that rupture the plasma membrane and can cause splitting of leaf and bark tissues. Prolonged periods of subzero temperatures can result in freeze induced desiccation and the production of free radicals under high irradiance at low or subzero temperatures. A comprehensive understanding of the biology of the species that is being investigated can greatly assist in identifying the type of injury that must be addressed. The type of injury, as well as the factors limiting freezing tolerance, can change from fall through mid-winter to late spring and this also needs to be taken into account. Finally, any protocols designed to assess freezing injury should be designed to take into account the above mentioned statements in order to ensure that the information derived from the study provides accurate information on the problem that is being investigated. |