Genome wide identification and expression analysis of CRK gene family in response to fungal pathogen signals in potato

Cysteine-rich receptor-like kinase (CRK) plays an important role in plant growth and environmental adaptation. In this study, potato CRK (StCRK) family members were identified, and their physical and chemical characteristics, evolutionary characteristics, subcellular location, chromosome location and expression patterns were analyzed. Eight StCRK members were identified, with amino acid size from 459 to 686 aa, molecular weight of 50.75–77.50 kD, and isoelectric point of 5.84–8.75. StCRKs were mainly located on plasma membrane. CRKs from potato (Solanum tuberosum), apple (Malus pumila Mill.), Thale Cress (Arabidopsis thaliana), rice (Oryza sativa), cotton (G. hirsutum), banana (Musa acuminata), and tomato (Solanum lycopersicum) could be divided into nine subgroups, and StCRKs were belonged to subgroups I (6 members) and VI (2 members). Moreover, StCRKs distributed on chromosomes 2, 3, and 5, contained two tandem repeat gene clusters, including four members. There were many cis-regulated elements in the StCRKs promoter region, which mainly respond to hormones, low temperature, defense and stress signals. After inoculating Phytophthora infestans (Pi) and Fusarium sulphureum (Fs), eight and six StCRKs gene differentially expressed, among them, StCRK4 and StCRK8 had the expression levels by more than eight times. It is speculated that they may respond to multiple fungal signals, and play an important role in potato′s broad-spectrum resistance to fungal diseases, and can be used as candidate genes for further needed on disease resistance and functional analysis.