Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/1996
Publication Date: N/A
Citation: Interpretive Summary: 1) Rationale: The goal of this work was to analyze genes of corn that code for seed proteins. 2) Accomplishments: The article discusses several seed protein genes in corn and compares their expression in two different strains; one which has been selected for high-protein content seeds, the other selected for low protein content in seeds. 3) Significance: The understanding of the expression of genes encoding seed proteins should enable scientists to produce corn that has improved protein quantity and quality.
Technical Abstract: The Illinois long term chemical selection strains of maize have been selected for high or low total protein content for more than 90 generations, and these were used in the present study to investigate the expression of genes encoding seed storage proteins. Analysis of the endosperm proteins by SDS-PAGE indicated a general trend in the level of certain polypeptides in different protein selection strains. As percent protein increased as a function of selection, the level of alpha-zeins also increased. Embryo protein profiles of IHP (Illinois High Protein) and ILP (Illinois Low Protein) analyzed by SDS-PAGE and immunoblot analysis indicated that these populations lack detectable globulin (GLB1) protein. However PCR amplification of DNA from IHP plants and subsequent Southern hybridization with a radiolabeled oligonucleotide probe specific for glbl intron2 confirmed that the glbl gene is present in the IHP population. The glbl gene expression patterns were analyzed using embryos from different developmental stages of maize kernels of both IHP and ILP strains. Levels of glbl transcripts were 10-fold lower in both IHP and ILP at 26 DAP as compared to standard functional alleles from maize inbred lines W64A and Va26. The reduction in steady state transcripts in ILP embryos was more than 30-fold to that of the standards. However transcript levels of glb2 and kd16 genes were not affected in these populations. Analysis of expression of various storage protein genes in the endosperm also revealed that the IBP and ILP populations lack detectable glb1 steady-state transcripts.