Impact of Cell-wall Structure and Composition on Plant Freezing Tolerance
Many plants experience freezing temperatures that can be damaging and even lethal. Current climate projections suggest that freezing events are likely to increase in early autumn and late spring, at times when plants are unprepared to deal with them. Previous literature has highlighted specific mechanical properties of the plant cell wall that may impact upon freezing tolerance. For example, the limiting pore size of the cell wall can influence ice nucleation and growth, whilst cell-wall stiffness can alleviate damage from freeze-induce dehydration. More recently, there is increasing evidence that the wall undergoes major modifications in order to prepare for freezing stress, with the observation that cell-wall thickness increases and differential regulation of genes encoding cell-wall modifying enzymes occurs after exposure to cold temperatures. These findings suggest that cell-wall structure or composition are necessary and contribute to plant freezing tolerance. With the advent of molecular genetic techniques, we can now explore in further detail what aspects of the cell wall are important to prevent freezing damage and identify targets to develop plants with enhanced freezing tolerance in the future.