Abstract:

PHR1 is a crucial factor in balancing plant disease resistance and low phosphorus stress resistance.To investigate the nature and function of the StPHR1 gene in potato and to explore the role of StPHR1 in the process of potato resistance to Alternaria solani infection,the CDS sequence of the StPHR1 gene was cloned by PCR technology using potatoes as the research material,and the structural,physicochemical properties,and phylogenetic relationships of StPHR1 were analyzed and predicted using bioinformatics software,then,the expression level of StPHR1 during the infection of potatoes by A.solani and under different hormone treatments was analyzed using qRT-PCR technology,and subcellular localization analysis of the protein was conducted using laser confocal microscopy technology.The results showed that the CDS of the StPHR1 gene was 1 353 bp,encoding 450 amino acids.The protein had a molecular formula of C₂₁₄₇H₃₃₉₉N₅₉₅O₇₁₁S₁₈,a molecular weight of 49.51 ku,and a theoretical isoelectric point of 5.07,encoding a hydrophilic,unstable protein with no signal peptide and no transmembrane structure.Its secondary structure consisted mainly of random coil and α-helix.Phylogenetic tree analysis revealed that the StPHR1 protein was most closely related to Arabidopsis thaliana; conservative domain analysis revealed that the StPHR1 protein,like other PHR1s,possesses both MYB-CC and MYB conserved structural domains at its C-terminus.Relative expression analysis found that StPHR1 was significantly induced by A.solani and salicylic acid,and it was hypothesized that StPHR1 played an important role in A.solani infection of potato and in the response to salicylic acid; and the subcellular localization showed that the StPHR1 protein was localized in the nucleus.It is hypothesized that StPHR1 may regulate potato resistance to A.solani through its MYB transcription factor activity and response to salicylic acid.

Key words: Potato, Alternaria solani, StPHR1, Bioinformatics analysis, Subcellular localization