Genetic analysis of opaque2 modifier loci in quality protein maize

Theor Appl Genet. 2008 Jul;117(2):157-70. doi: 10.1007/s00122-008-0762-y. Epub 2008 Apr 22.


Quality protein maize (QPM) was created by selecting genetic modifiers that convert the starchy endosperm of an opaque2 (o2) mutant to a hard, vitreous phenotype. Genetic analysis has shown that there are multiple, unlinked o2 modifiers (Opm), but their identity and mode of action are unknown. Using two independently developed QPM lines, we mapped several major Opm QTLs to chromosomes 1, 7 and 9. A microarray hybridization performed with RNA obtained from true breeding o2 progeny with vitreous and opaque kernel phenotypes identified a small group of differentially expressed genes, some of which map at or near the Opm QTLs. Several of the genes are associated with ethylene and ABA signaling and suggest a potential linkage of o2 endosperm modification with programmed cell death.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Chromosome Segregation
  • Crosses, Genetic
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Genetic Linkage
  • Genetic Markers
  • Inbreeding
  • Physical Chromosome Mapping
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Quantitative Trait Loci*
  • Zea mays / genetics*


  • Genetic Markers
  • Plant Proteins