Multiple Subcellular Localizations of Dehydrin-like Proteins in the Embryonic Axes of Common Beech (Fagus sylvatica L.) Seeds During Maturation and Dry Storage

Abstract

The accumulation and localization of dehydrin-like proteins were analyzed in the embryonic axes of beech (Fagus sylvatica L.) seeds during maturation between the 12th and 19th week after flowering and in the dry state after 2 years of storage. Three dehydrin-like proteins were reported using an antibody specific to the K-segment, and their subcellular localization was investigated using an immunocytochemistry approach. All dehydrin-like proteins were phosphorylated, and two, with molecular masses of 26 and 44 kDa, accumulated in mature seeds. During seed maturation, dehydrin-like proteins were frequently detected inside the round or segmented nuclei, along the cell plasma membrane and associated with small vesicles. Moreover, they were found to be attached to the mitochondrial and amyloplast envelopes. These proteins were also located in the cytosol and were associated with membrane structures throughout the cytoplasm. Conversely, in the embryonic axes of stored seeds, fewer specific locations were found; dehydrin-like proteins were associated mostly with amyloplasts, and were detected to a lesser extent in the nuclei, vacuoles, and other cytoplasmic structures. Bioinformatic tools were used to predict the putative beech dehydrin sites that interact with DNA, proteins, and lipid membranes to highlight the reported subcellular locations. Here, we present and discuss the possible roles of dehydrin-like proteins in seeds with respect to their subcellular localizations.