Determination of physiological and genetic basis of tolerance to de-acclimation in wheat and barley

With global warming becoming increasingly noticeable, it might seem that the issue of winter hardiness and its various elements will become less important. However, this is a misconception – it is likely that only the most important elements of winter hardiness in a given region will change. In the climate zone to which Poland belongs, plant overwintering is mainly determined by frost resistance, and it is this trait that research has focused on. Therefore, there are many publications on this subject, and some genes associated with frost resistance in many species and the mechanisms influencing the expression of this trait are known. However, little is known about resistance to de-acclimation, and research to date has mainly focused on woody plants. There are actually two types of de-acclimation, with potentially different genetic and physiological bases: 1) “Passive” de-acclimation independent of environmental conditions – the highest level of frost resistance occurs in most plants in the middle of winter, and from then on, frost resistance gradually decreases. This may be related to the onset of generative development or the depletion of reserves accumulated by plants before winter. 2) “Active” de-acclimation – plants de-acclimatise as a result of higher temperatures, e.g. during periods of warming in winter. This project will determine the characteristics of the response to active de-acclimation in 600 lines/varieties of winter barley and 600 lines/varieties of winter wheat. The physiological mechanisms of tolerance and sensitivity to active de-acclimation will be identified. A comparison will also be made to determine whether the traits of active (during winter) and passive (tolerance to spring frosts) de-acclimation tolerance are phenotypically related and, in the case of barley, whether they have a similar genetic basis. In connection with the premises about the relationship between de-acclimation tolerance and antioxidant activity, the characteristics of antioxidant activity in response to desiccation will be obtained in the 10 most sensitive and 10 most tolerant lines/ wheat and barley varieties, and a simple diagnostic test will be developed to test the antioxidant activity of seedlings in order to determine the degree of de-acclimation tolerance. The project will also identify candidate genes potentially associated with the response to active de-acclimation in wheat. Markers of active de-acclimation tolerance will also be obtained for each species studied.