Abstract: By homology cloning, we obtained the core sequences of 7 calcium-dependent protein kinase (CDPK) genes, CaCPK1 to CaCPK7, from salt-tolerant Chenopodium album. Quantitative real-time PCR revealed that CaCPK1, CaCPK2, CaCPK3 and CaCPK4 were significantly induced by salt stress with different patterns. The expression pattern of CaCPK1, CaCPK2 and CaCPK3 was also changed in C. album under both H₂O₂ and abscisic acid (ABA) stresses. Diphenylene iodonium (DPI, inhibitor of H₂O₂ synthesis) and sodium tungstate (Na₂WO₄, inhibitor of ABA synthesis) significantly inhibited the expression of CaCPK1, CaCPK2 and CaCPK3 on exposure to 300 mmol·L^–1NaCl. We obtained the full-length sequences of 3 CDPKs―CaCPK1, CaCPK2 and CaCPK3―by 3′- and 5′-RACE, which contain open reading frames of 1 632, 1 704, and 1 590 bp, respectively. The production of ABA and H₂O₂ induced by salt may be involved in induction of CaCPK1, CaCPK2 and CaCPK3, facilitating the analysis of the function of CDPK gene family in C. album.

Key words: Chenopodium album, salt stress, signal transduction pathway, calcium-dependent phosphokinase, salt-tolerant plant