Isolation and characterization of the gene for the biosynthesis of the rice storage protein using the mutants

prolamin regulatory gene mutantThe表达式模式mRNA from the immature seeds of theprolamin mutant, which showed the decreased level of several prolamin molecules，was analyzed by the differential display methods. the expression pattern of some bands in mutantsdiffered from that of the original variety. mutant for the transportation and accumulation ofglutelinProglutelin precursor high accumulation mutant (57h), esp2 mutant，lacked protein disulfide isomerase (PDI) one of the molecular chaperonat both the RNA and protein level . These results suggest that PDI plays and essential role in thesegregation of proglutelin and prolamin polypeptides within the ER lumen. the Esp2 gene differedfrom the gene coding the PDI and the other esp2 mutant line also showed depressed PDI mRNA level。This suggests the Esp2 gene codes the gene activator protein of PDI gene. the deduced aminoacid sequence of the partially isolated PDI shows that rice sequence identity to maize, barleywheat and castor bean clones is 84.8%, 84.2%, 83.9% and 62.5%，glutelin structural gene mutantThe genetic analyses show that三种类型的glutelinα-2 subunit lacking mutants (α-2L mutant) were the mutants of the same locus for the structuralgene of glutelin. The gene of α-2L mutant was named as Glu4, Which was corresponded to cDNA cloneglua1。

・ prolamin regulatory gene mutantThe expression pattern of mRNA from the immature seeds of the prolamin mutant, which showed the decreased level of several prolamin molecules, was analyzed by the differential display methods. The expression pattern of some bands in mutants differed from that of the original variety.・ The mutant for the transportation and accumulation of glutelinProglutelin precursor high accumulation mutant (57H), esp2 mutant, lacked protein disulfide isomerase (PDI), one of the molecular chaperon, at both the RNA and protein levels. These results suggest that PDI plays and essential role in the segregation of proglutelin and prolamin polypeptides within the ER lumen. The Esp2 gene differed from the gene coding the PDI and the other esp2 mutant line also showed depressed PDI mRNA level. This suggests that the Esp2 gene codes the gene activator protein of PDI gene. The deduced amino acid sequence of the partially isolated PDI shows that rice sequence identity to maize, barley, wheat and castor bean clones is 84.8%, 84.2%, 83.9% and 62.5%, respectively.・ glutelin structural gene mutantThe genetic analyses show that three types of glutelin α-2 subunit lacking mutants (α-2L mutant) were the mutants of the same locus for the structural gene of glutelin. The gene of α-2L mutant was named as Glu4,. Which was corresponded to cDNA clone GluA1.