Molecular Cloning and Expression Analysis of Triticale Phytocystatins During Development and Germination of Seeds

Three triticale cDNAs encoding inhibitors of cysteine endopeptidases, belonging to phytocystatins, have been identified and designated as TrcC-1, TrcC-4 and TrcC-5. Full-length cDNAs of TrcC-1 (617 bp) and TrcC-4 (940 bp), as well as a fragment of TrcC-5 cDNA (369 bp), were obtained. A high-level identity of the deduced amino acid sequence of TrcCs with other known phytocystatins, especially with wheat and barley, has been observed. Moreover, the presence of conserved domain, containing the G and W residues, the sequence of QxVxG and the sequence of LARFAV, characteristic for plant cysteine endopeptidase inhibitors, has been noted. The profiles of TrcC-1 and TrcC-5 mRNA levels in the developing seeds of two triticale cultivars that differ in their resistance to preharvest sprouting (Zorro and Disco) were similar. However, the expression of TrcC-4 was, higher in the developing seeds, and in the scutellum of germinating seeds of a cultivar more resistant to preharvest sprouting (Zorro) than in the less resistant (Disco). Additionally, the expression of TrcC-4 remained longer in developing seeds of Zorro as compared to Disco. The performed studies suggest that TrcC-4 might have an influence on the higher resistance of Zorro cultivar to preharvest sprouting.