Genome-wide characterization of sugarcane catalase gene family identifies a ScCAT1 gene associated disease resistance

In plants, catalase (CAT) mainly scavenges H₂O₂ from reactive oxygen species (ROS) and regulates the growth and development. So far, genome-wide identification of CAT gene family in Saccharum has not yet been reported. Here, 16 SsCAT genes were identified based on a Saccharum spontaneum genome. They were clustered into three subfamilies, with closer genes sharing similar structures. Most SsCAT proteins contained three conserved amino acids, one active catalytic site, one heme-ligand signature, and three peroxisomal targeting signal 1 (PTS1) sequences. The cis-regulatory element prediction revealed that SsCAT genes were involved in growth and development, and in response to various hormones and stresses. RNA-Seq databases showed that SsCAT genes were differentially expressed in Saccharum tissues and under cold, drought, and Sporisorium scitamineum stresses. The ScCAT1 gene transcript (GenBank accession number KF664183) and relevant CAT activity were up-regulated under S. scitamineum stress. Overexpression of ScCAT1 gene in Nicotiana benthamiana could enhance its resistance to pathogen infection through scavenging of excessive toxic ROS and up-regulated expressions of genes related to hypersensitive response (HR), ROS and salicylic acid (SA) pathways. This study provides comprehensive information for the CAT gene family and sets up a basis for its function identification in sugarcane.