Freezing stress presents a severe threat for winter wheat(Triticum aestivum L.)during overwintering.Dehydration plays a significant role in plant cold-hardiness.In this study,dehydration-related traits were investigated between highly and tender freezing-tolerant winter wheat cultivars during the overwintering period.Accompanied by a decrease in temperature,the water content in crowns of highly freezing-tolerant winter wheat was significantly lower compared to that of tender freezing-tolerant winter wheat(control).The ratio of free and bound water content had slight changes in highly freezing-tolerant winter wheat,though there were wide fluctuations in the control.The transcript levels of dehydration-related genes were more expressed in the highly freezing-tolerant winter wheat than those in the control under freezing stress.The plant growth also showed significant differences between the two winter wheat cultivars.Based on these results,the study proposed that the highly freezing-tolerant winter wheat produces higher expression of dehydrins under freezing stress,causing additional dehydration in the tissue to avoid cell death caused by the formation of ice crystals.Furthermore,winter hardy cultivar also reduced the percentage of free water content that inhibited plant growth,and regulated the water composition for plant survival under freezing stress.
展开▼
