Analysis of seed storage protein genes of oats.
We have isolated genomic clones encoding the two major classes of seed storage proteins in oats, the 12 S globulins and the avenins. The globulin genes encode glutamine-rich, sulfur-poor storage proteins that are highly conserved in sequence and structure. The globulin genes contain three short introns whose positions in the coding sequence are the same as in storage globulin genes in legumes and other dicots. The avenin genomic clone contains four tightly linked genes that belong to both of the two avenin gene subfamilies. The avenin genes encode glutamine-rich, lysine-poor proteins that vary in length due to differences in the number of peptide repeats. Although globulin and avenin genes are expressed coordinately during oat seed development, their promoter regions do not contain any conserved sequence elements that might determine developmental timing. Previous studies showed that there are roughly equal amounts of globulin and avenin mRNAs in developing oat seed, despite there being much more globulin than avenin in mature seed. Storage protein synthesis in oats must therefore be controlled partially by post-transcriptional mechanisms. Sequence analysis of globulin and avenin genes has provided several clues as to why globulin mRNAs may be translated more efficiently than avenin mRNAs.
Shotwell
M A
MA
Department of Plant Sciences, University of Arizona, Tucson 85721.
Boyer
S K
SK
Chesnut
R S
RS
Larkins
B A
BA
D000485:Allergens; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D001483:Base Sequence; D003001:Cloning, Molecular; D003062:Codon / Q000235:genetics; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D002523:Edible Grain / Q000235:genetics*; D017343:Genes, Plant; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010940:Plant Proteins / Q000235:genetics*; D055315:Prolamins; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D015183:Restriction Mapping; D055314:Seed Storage Proteins
D000485:Allergens; D052179:Antigens, Plant; D003062:Codon; D010940:Plant Proteins; D055315:Prolamins; D012333:RNA, Messenger; D055314:Seed Storage Proteins; C059777:cruciferin protein, Brassica napus; D004247:DNA