Abstract

In Brassica napus, ATP6 is related to Pol cytoplasmic male sterility. To understand the mechanism of Pol CMS, proteins which interact with ATP6 were screened in a yeast two-hybrid system. A partial sequence of a putative and ascorbate peroxidase (Bn-APX) was isolated from Brassica napus. By use of rapid amplification of cDNA ends method, the full length of Bn-APX coding sequence was cloned. The deduced amino acid sequence contained 438 amino acid residues with a conserved ascorbate peroxidase domain and shared 77% identity with that of APX fromArabidopsis thaliana. Further analyses revealed that the region of Bn-APXinteracting with ATP6 was at its c-terminal. It was also observed that theexpressions of ATP6 and Bn-APX were strongly similar in the floral tissue of CMS line and the restoring line. Furthermore, in restoring line, the expression of Bn-APXis higher in the flower than that in other tissues.

Key words: ATP6, Pol CMS, yeast two-hybrid system, ascorbate peroxidase.