Identification and expression analyses of chitinase genes in mulberry (Morus L) plants

In the present study, we identified chitinase genes in the genome of mulberry for the first time. The mulberry genome encodes 20 chitinase genes, which are grouped into two main families and organized into five classes. The genomic structures and phylogenetic relationships of mulberry chitinase genes were analyzed, which provided a genetic basis for understanding the functions of these genes. We further investigated the expression of mulberry chitinase genes in five different tissues including root, bark, bud, flower, and leaf. Our results showed that there was no correlation between the spatial expression patterns of chitinase genes and their classification based on the conserved domains. Furthermore, six mulberry chitinase genes were used to detect transcriptional differences in their response to insect wounding, fungal infection, and biochemical elicitors. We found that different mulberry chitinase genes were induced by insect wounding and fungal infection, suggesting that these chitinases help the plant to cope with the challenges from insects and fungi.