Polymorphism and Expression Analysis of two Potato Receptor Genes (LysM-RLKs), Following Alternaria solani Infection

The Lysin motif in receptor-like kinases (LysM-RLKs) bind to chitin or chitin components of the fungal pathogen cell wall to perceive their invasion. To study the LysM-RLK domains of potato genome involved in Alternaria solani response, the putative LysM-RLKs were bioinformatically assessed, sequenced and their expression levels were measured in a susceptible (Russet Burbank) and relatively resistant (F06037) genotypes, following inoculation of the pathogen. A total of 35 putative LysM-RLKs were detected in potato genome, of which 26, 5 and 4 LysM-RLK had none, one and two LysM motifs, respectively. Among 9 receptors containing LysM-RLK domains, two proteins showed a significant overexpression following A. solani infection.
PGSC0003DMP400061331 protein with two LysM motifs had a higher expression level than PGSC0003DMP400060418 protein with one LysM motif. Both proteins had 98% and 81% coverage with Arabidopsis thaliana CERK1 protein, respectively. Multiple sequence alignment (MSA) of LysM motifs from both proteins of two potato genotypes with that of Arabidopsis thaliana CERK1 revealed no difference between genotypes with respect to LysM motif sequence. Interestingly, the LysM motifs from PGSC0003DMP400061331 protein had an “NRD” insertion as compared to its second LysM motif, PGSC0003DMP400060418, and Arabidopsis taliana CERK1 LysM motifs. Such changes may have occurred through deletions or duplications. Alteration of DNA sequences by genome editing methods may shed light on the role of these genes in the field of resistance or susceptibility to A. solani leading to generation of resistant transgenic plants to devastating fungal diseases.