耐弱光马铃薯品种筛选及转录因子编码基因StPIF3的克隆与功能分析OA

Based on measurements and comparisons of growth traits,chlorophyll fluorescence parameters,and other related indi-ces in nine potato varieties under low-light treatment,the cultivar"Atlantic"was identified as low-light tolerant by principal component analysis.To investigate genes involved in the low-light response of"Atlantic",we performed transcriptome analysis after treatment with a light intensity of 10 μmol m-2 s-1 for 48 h.Using GO enrichment,KEGG pathway analysis,and transcrip-tion factor prediction,we identified the light-responsive transcription factor gene StPIF3 and cloned its full-length cDNA.StPIF3 was introduced into tobacco via agrobacterium-mediated transformation,and T1 transgenic lines were obtained by selfing.Bioin-formatics analysis,RT-qPCR,and chlorophyll fluorescence measurements were used to characterize and validate its function.StPIF3 encodes a 716-amino-acid protein with a predicted molecular weight of 76.77 kD and an isoelectric point of 7.26,and it is predicted to be hydrophilic and unstable.The StPIF3 protein contains a typical HLH domain and belongs to the bHLH family;phylogenetic analysis indicated that StPIF3 is most closely related to the tobacco homolog.Under 50 μmol m-2 s-1 light intensity,transgenic tobacco plants showed significantly higher Fv/Fm,qP,ETR,ETRmax,and SPAD values than wild-type plants,whereas F0 was lower.Overall,overexpression of StPIF3 markedly improves electron transport and light energy use efficiency,thereby enhancing photosynthetic performance and low-light tolerance.