Abstract
We identified a 23 kDa protein (P23k) in barley scutellum, which is apparently associated with starch degradation in the endosperm during germination. The function of the protein is still unknown. Here we reported that this protein is barley-specific and coordinately regulated by the supply of sugars. We investigated the expression and localization of the protein at various developmental stages (seed development, germination, and vegetative stages),using Northern hybridization, Western blotting, in situ hybridization and immunocytochemistry. The P23k protein was specifically expressed in scutellum during germination. It was also expressed when leaf blades were fully developed and acted as a source tissues. Finally, it was specifically expressed in the nucellar projection, the vascular bundles and the aluerone cells during seed development (sink tissue). As these tissues are all involved in the supply of nutrients , we believe that the P23k is related to the translocation of nutrient.
