Abstract
Plants which undergo subzero temperatures in winter have some mechanisms to survive under freezing. The exposure of these plants to subzero temperatures results in extracellular freezing which brings the dehydration and mechanical stresses. In Arabidopsis, it has been revealed that the extracellular calcium increases the tolerance to freeze-induced mechanical stress, the mechanism of which is involved in the membrane resealing via plant synaptotagmin, SYT1. But it is unknown whether plants which can survive under freezing generally possess this calcium-dependent freezing tolerance system. In this study, with monocot species, we investigated the generality of calcium-dependent mechanical stress tolerance as a freezing tolerance system. We used leaf sections of spring oat, winter rye and winter wheat. Calcium-dependent freezing tolerance was confirmed in all of them. In addition, it was confirmed that these monocots possess SYT1-like protein in plasma membrane fraction with anti-Arabidopsis SYT1 antibody. Here, we will report the results from the analyses of the involvement of synaptotagmin into the calcium-dependent freezing tolerance by using anti-Arabidopsis SYT1 antibody.
