Genome-wide identification and characterization of PIF genes and their response to high temperature stress in potato

Abstract

<p id="C3">Phytochrome interacting factors (PIFs) belong to the basic helix-loop-helix (bHLH) transcription factor family, which integrates external environmental signals such as light and temperature with plant endogenous signal pathways, and then form a complex signal transduction network to precisely regulate the growth and development of plants. Up to now, there are few studies of PIF family genes in potato. Identification and analysis of StPIF family members will help to further improve the yield and quality of potatoes. In this study, BlastP analysis was performed in the potato genome database using <italic>Arabidopsis</italic> PIFs family member protein sequences as source sequences and seven StPIFs family members were identified. Systemic evolution, chromosome distribution, replication events, protein physicochemical properties, gene structure, motif prediction, promoter cis-acting elements, gene expression pattern, and the response to high temperature stress were also conducted. These results showed that all members of the StPIFs gene family contain Motif 1 (bHLH domain) and Motif 2 (APB domain); multiple cis-regulatory elements involved in light response, hormones, drought, low temperature, and circadian rhythm as well as defense and stress response regulatory elements were predicted in the promoter regions of the <italic>StPIF</italic> genes. Results of gene expression patterns and high temperature stress response at budding stage revealed that StPIFs family members had obvious tissue expression specificity, indicating their functional differentiation, and most <italic>StPIFs</italic> members had obvious responses to biotic stress and abiotic stresses including high temperature. In conclusion, these foundlings greatly enriched the understanding of the members of the StPIF family, and laid a theoretical foundation for further exploring the functions of <italic>StPIF</italic>s genes in responses to biotic stress and abiotic stress during potato growth period including high temperature at tuber stage.