Expression of a small heat shock protein (CTL-hsyapr) screened by cDNA-AFLP approach is correlated with hydroxysafflor yellow A in safflower (Carthamus tinctorius L.)

Hydroxysafflor yellow A (HSYA) is the main active chemical compound present in florets of Carthamus tinctorius L. cDNA-amplified fragment length polymorphism (AFLP) was used to systematically investigate which genes were associated with the presence or absence of HSYA in safflower. Eighty pairs of possible primer combinations were performed on two cDNA pools representing HSYA-present and HSYA-absent plants. Five transcript-derived fragments (TDFs) were identified with low recombination, two of them were sequenced successfully and named as TDF-A and TDF-C. The full-length cDNA of CTL-hsyapr was 697 bp long with an open reading frame (ORF) of 411 bp encoding a polypeptide of 136 amino acid residues. The deduced amino acid sequence of the CTL-hsyapr gene shared a high homology to other known small heat shock proteins (sHSPs). Semi-quantitative RT-PCR analysis revealed that mRNA of TDF-A only accumulated in HSYA-present lines, and TDF-C only expressed in HSYA-absent lines.