A transgenic rice seed accumulating an anti‐hypertensive peptide reduces the blood pressure of spontaneously hypertensive rats

Abstract
RPLKPW is a potent anti‐hypertensive peptide designed according to the structure of ovokinin(2–7) (RADHPF). In this study, we generated transgenic rice plants that accumulate the RPLKPW peptide as a fusion protein with the rice storage protein glutelin. The engineered peptide is expressed under the control of endosperm‐specific glutelin promoters and specifically accumulates in seeds. Oral administration of either the RPLKPW‐glutelin fraction or transgenic rice seeds to spontaneously hypertensive rats (SHRs) significantly reduced systolic blood pressures. These results suggest the possible application of transgenic rice seed as a nutraceutical delivery system and specifically for administration of active peptides in hypertension.