The pea seed storage protein legumin was synthesized, processed, and accumulated stably in transgenic rice endosperm.

摘要

To improve the amino acid composition of rice grain, the seed storage protein legumin from Pisum sativum was expressed in the endosperm of transgenic rice plants. Genomic or cDNA coding sequence of the pea legumin gene (LegA), including the 3'-downstream region, was placed under transcriptional control of either a 1.8 or 5.1 kb promoter of the rice glutelin gene (Gt1). The 5.1 kb promoter conferred a higher level of legumin accumulation in mature seeds than the 1.8 kb promoter, whilst the use of genomic or cDNA coding sequence did not significantly affect expression level. Segregation analysis of legumin in transgenic plants suggested monogenic Mendelian inheritance, indicating a single locus or closely linked loci of gene insertion. Western blotanalysis indicated that the legumin precursor is cleaved endoproteolytically into acidic and basic subunits in the rice endosperm, as in pea cotyledons.