A soybean cell wall protein is affected by seed color genotype.
The dominant I gene inhibits accumulation of anthocyanin pigments in epidermal cells of the soybean seed coat. We compared saline-soluble proteins extracted from developing seed coats and identified a 35-kilodalton protein that was abundant in Richland (genotype I/I, yellow) and much reduced in an isogenic mutant line T157 (genotype i/i, imperfect black seed coats). We purified the 35-kilodalton protein by a novel procedure using chromatography on insoluble polyvinylpolypyrrolidone. The 35-kilodalton protein was composed primarily of proline, hydroxyproline, valine, tyrosine, and lysine. Three criteria (N-terminal amino acid sequence, amino acid composition, and sequence of a cDNA) proved that the seed coat 35-kilodalton protein was PRP1, a member of a proline-rich gene family expressed in hypocotyls and other soybean tissues. The levels of soluble PRP1 polypeptides and PRP1 mRNA were reduced in young seed coats with the recessive i/i genotype. These data demonstrated an unexpected and novel correlation between an anthocyanin gene and the quantitative levels of a specific, developmentally regulated cell wall protein. In contrast, PRP2, a closely related cell wall protein, was synthesized later in seed coat development and was not affected by the genotype of the I locus.
Lindstrom
J T
JT
Department of Agronomy, University of Illinois, Urbana 61801.
Vodkin
L O
LO
D000595:Amino Acid Sequence; D002473:Cell Wall / Q000737:chemistry / Q000502:physiology*; D003116:Color; D017343:Genes, Plant / Q000235:genetics; D005838:Genotype; D006909:Hydroxyproline / Q000032:analysis; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009154:Mutation; D010455:Peptides / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000302:isolation & purification; D011205:Povidone / Q000031:analogs & derivatives / Q000378:metabolism; D055232:Proline-Rich Protein Domains; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D012639:Seeds / Q000737:chemistry / Q000235:genetics*; D013025:Glycine max / Q000737:chemistry / Q000235:genetics*; D014158:Transcription, Genetic
D010455:Peptides; D010940:Plant Proteins; D012333:RNA, Messenger; C077842:polyvinylpolypyrrolidone; D011205:Povidone; D006909:Hydroxyproline