Abstract:Peroxidase (POD) genes were isolated from three Caragana species, C. korshinskii, C. microphylla and C. intermedia (designated as CkPOD, CmPOD and CiPOD, respectively) using homologybased cloning techniques, and their expression profiles under drought stress conditions were investigated. All of the cDNAs of CkPOD, CiPOD and CmPOD contain an open reading frame (ORF) of 1 074 bp, encoding a protein of 357 amino acids with a theoretical molecular weight of 38.7 kD. Phylogenetic analysis showed that these three Caragana PODs could be clustered into one clade with their isoforms from leguminosae, including Cicer arietinum. The PODs of C. korshinskii and C. microphylla showed a closer relationship compared to C. intermedia POD, corresponding to evolutionary history of the three Caragana plants. Real time RTPCR revealed that the expression of the Caragana POD genes was strongly induced by PEGsimulated drought stress, showing that the Caragana POD genes play an important role in resisting droughttolerance. These results may provide theoretical and experimental basis for understanding the droughttolerance mechanism of the Caragana plants and for their utilization in desert improvement and vegetation restoration programs.