Mechanisms Underlying Freezing and Desiccation Tolerance in Bryophytes.
Bryophytes are small land plants that have many morphological and physiological features different from vascular plants. With distinct water relations of bryophytes, many bryophyte species exhibit high degrees of tolerance to freezing and desiccation. The tolerance is sustained by the constitutive repair mechanism and the inducible mechanism regulated by environmental signals that provoke specific responses within the cells. Bryophyte cells sense changes in environmental conditions such as decreases in osmotic potential and temperature and that some responses are likely to be mediated by the stress hormone, abscisic acid. Due to their simple structures and high degrees of dehydration tolerance, bryophytes are useful for physiological studies on abiotic stress response and also for analysis of signal sensing and transduction of environmental signals. Furthermore, the basal phylogenetic position of bryophytes in land plants provides many insights into the evolutionary events for conquest of land by the ancestors of plants and subsequent diversification of species as well as their survival strategies in the terrestrial environment.
['Takezawa|Daisuke|D|']
D000040:Abscisic Acid D000064:Acclimatization D044002:Bryophyta D058639:Cold-Shock Response D003681:Dehydration D005615:Freezing D018506:Gene Expression Regulation, Plant D000074267:Organism Hydration Status D010940:Plant Proteins D015398:Signal Transduction D014867:Water
Freezing Desiccation Bryophytes Abscisic acid Environmental stress