Cloning of Catalase 2 (CAT2) Gene and Study on Its Expression Pattern in Nicotiana tabacum L.

The full-length cDNA of Catalase 2 (CAT2) from Nicotiana tabacum var. NC89 was cloned usingspecific primers designed according to CAT2 mRNA sequences in other plants. Amino acid sequence alignment indicated that CAT2 contains a complete reading frame (ORF) of 1479 bp, which encodes 492 amino acid residues. Phylogenetic analysis showed that NC89 CAT2 shares high similarity with the CAT2 gene from N. benthamiana. Quantitative real-time PCR (qPCR) analysis revealed that CAT2 is highly expressed in petal and calyx, while less expressed in leaves, stems, seeds, and roots. The expression of NC89 CAT2 was enhanced by abiotic and biotic stressors, such as mechanical damage, osmotic pressure, low temperature, high temperature, drought and PVY infection. It was suggested that CAT2 plays an important role in growth, development, and interplay of abiotic and biotic stresses in plant.