Fig. 2.

Verification of the C–S–A gene system for hull pigmentation. (A) Complementation and overexpression of C1 in NIP. Both kinds of transgenic plants have brown apiculi. (B) Complementation of C1 in HC1. Brown hull color was restored in transformants. (C) RNAi of C1 in HC2. Purple hull color was lost in transformants. (D) Overexpression of the S1 CDS in PA NIL. The PA NIL has the same pigmentation pattern as HC5. The hull color of transformants changed to purple. (E) Complementation of A1 in HC3. Transgenic lines restored the purple hull phenotype. (F) Genetic model for hull pigmentation. Green boxes indicate functional alleles; white boxes indicate non-functional alleles. The letters in parentheses denote genotype of C1, S1, and A1, in which upper-case letters represent functional genotypes, and lower-case letters indicate non-functional genotypes. Two independent transgenic lines are shown for each transformation test.