Isolation and characterisation of a 21 kDa aleurone-specific protein from rice (Oryza sativa) seed

A protein of 21 kDa was isolated from the aleurone layer of Nootripathu rice seed. Antibodies were raised against the HPLC-purified protein and tested by western blotting. Aleurone specificity of this protein was confirmed by immunolocalisation assay. The immunolocalisation study also confirmed the presence of a similar protein in other varieties of rice. During the developmental stage this protein is selectively expressed in rice seed, as shown by western blot analysis. Expression of this protein increases after the milky stage, as shown by protein dot blot analysis. HPLC analysis revealed that this protein is less hydrophobic than other, eg those from the endosperm. This novel protein may be a possible candidate for targeting into the endosperm to enhance the nutritional value of polished rice.