Expression of CT-wpr, screened by cDNA-AFLP approach, associated with hydroxysafflor yellow A in Carthamus tinctorius L.

Hydroxysafflor yellow A (HSYA) is the main active compound in petals of Carthamus tinctorius L. In this study, we used cDNA-amplified fragment length polymorphism (cDNA-AFLP), coupled with bulked segregant analysis (BSA), to screen differentially expressed genes in two cDNA pools, and obtained 2560 reproducible bands ranging from 1500 bp to 100 bp with 64 AFLP primer combinations. Two TDFs (TDF-4 and TDF-11) were identified with low recombination and successfully sequenced. The genetic distance of the linkage map from the HSya locus was 9.9 cM and 2.9 cM, respectively. The full-length cDNA sequence of TDF-11 gene, designated as CT-wpr (GenBank Accession No. GU227360) was cloned. Nucleotide sequence alignment revealed that CT-wpr shared 66% identity with Populus trichocarpa. Semi-quantitative RT-PCR analysis revealed that the mRNA of the two TDFs only expressed in the HSYA-absent line. Possible functions of CT-wpr are also discussed.