Fig. 3

Alternative pathways that would explain why contrasted frost vulnerabilities are observed after previous drought exposure. Osmolarity of intracellular sap, controlled notably by the ratio between soluble carbohydrates and water content, could be considered the main driver. On the right path, intense and/or late drought is expected to concentrate cell sap, increasing the probability of extracellular ice nucleation. The low chemical potential of ice would pull water, further increasing cell osmolarity. On the left path, long and/or early drought prevents timely increase in solutes, through reduction in carbon reserves. Intracellular freezing is expected to happen more often and at higher freezing temperature, inducing cellular damages