Sweeney, M.T., Thomson, M.J., Pfiel, B.E., McCouch, S.R. (2006) Caught red-handed: Rc encodes a basic helix-loop-helix protein conditioning red pericarp in rice. Plant Cell. 18:283-294.
Criteria:
The Rc locus was positionally cloned from rice. A mapping population between a cultivar (Jefferson) with the recessive, null allele, rc was crossed with a dominant allele ( Rc) Oryza sativa with red pericarp. By recombination analysis, a small stretch of genomic sequence was delimited within which an open reading frame annotated as a bHLH containing protein was identified. The null allele in Jefferson was found to be identical to that of Nipponbare, and has a 14bp indel that introduces a frameshift resulting in a premature stop codon. This frameshift,resulting in a white pericarp, occurs upstream of the basic helix-loop-helix motif responsible for the regulation of proanthocyanidin production. A second functional allele, Rc-s was cloned from an indica cultivar and confirmed that the Rc locus was the source of the red pericarp phenotype.
The null allele rc DQ204736 (cv Jefferson) is identical to Nipponbare (shown here). Two other alleles: 1)Rc DQ204737 (O. rufipogon) - the dominant functional allele; Rc-s DQ204738 (cv Surjamkuhi)which has brown spots on a reddish background.
Structural Annotation:
This work is supported by grants (DBI-0321538/DBI-0834043) from the National Science Foundation and funds from the Georgia Research Alliance, Georgia Seed Development, and University of Georgia.