In eukaryotic cells, nucleocytoplasmic trafficking of macromolecules is largely 
mediated by Karyopherin β/Importin (KPNβ or Impβ) nuclear transport factors, and 
they import and export cargo proteins or RNAs via the nuclear pores across the 
nuclear envelope, consequently effecting the cellular signal cascades in 
response to pathogen attack and environmental cues. Although achievements on 
understanding the roles of several KPNβs have been obtained from model plant 
Arabidopsis thaliana, comprehensive analysis of potato KPNβ gene family is yet 
to be elucidated. In our genome-wide identifications, a total of 13 StKPNβ 
(Solanum tuberosum KPNβ) genes were found in the genome of the doubled monoploid 
S. tuberosum Group Phureja DM1-3. Sequence alignment and conserved domain 
analysis suggested the presence of importin-β N-terminal domain (IBN_N, PF08310) 
or Exporin1-like domain (XpoI, PF08389) at N-terminus and HEAT motif at the 
C-terminal portion in most StKPNβs. Phylogenetic analysis indicated that members 
of StKPNβ could be classified into 16 subgroups in accordance with their 
homology to human KPNβs, which was also supported by exon-intron structure, 
consensus motifs, and domain compositions. RNA-Seq analysis and quantitative 
real-time PCR experiments revealed that, except StKPNβ3d and StKPNβ4, almost all 
StKPNβs were ubiquitously expressed in all tissues analyzed, whereas 
transcriptional levels of several StKPNβs were increased upon biotic/abiotic 
stress or phytohormone treatments, reflecting their potential roles in plant 
growth, development or stress responses. Furthermore, we demonstrated that 
silencing of StKPNβ3a, a SA- and H2O2-inducible KPNβ genes led to increased 
susceptibility to environmental challenges, implying its crucial roles in plant 
adaption to abiotic stresses. Overall, our results provide molecular insights 
into StKPNβ gene family, which will serve as a strong foundation for further 
functional characterization and will facilitate potato breeding programs.