Transcriptome sequencing elucidates the adaptation mechanisms of Pyrus betulifolia to cold and drought conditions

Cold and drought are two common abiotic stress factors that adversely affect the growth and yield of pear worldwide. Pyrus betulifolia, a widely used rootstock for pear, exhibits both cold and drought tolerance. Efforts to understand the mechanism of stress response will be pivotal for improving the abiotic stress resistance ability of pear. In this study, transcriptome sequencing was performed on leaves of P. betulifolia after treatment with cold and drought stresses. A total of 1143 differentially expressed genes (DEGs) and 6380 DEGs under cold and drought conditions were identified, respectively. Next, we performed an overlap analysis of two sets of transcriptome data. And 389 DEGs were identified, suggesting that there was a cross-talk in the signal pathways of cold and drought stresses. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that these DEGs were mainly enriched in plant hormone signal transduction, biosynthesis of secondary metabolites, plant-pathogen interaction, and metabolic pathways. Further exploration of the above DEGs responding to both cold and drought stresses has been done, mainly focusing on responsive plant hormone and polyamine pathways, as well as transcription factors. In addition, ten DEGs encoding TFs, which were considered to be positively response to cold and drought, and five functional genes were detected by the qRT-PCR. Overall, these results revealed potential genes associated with cold and drought stress tolerance in P. betulifolia. And characterization of these genes will shed light on the improvement of plant stress tolerance through molecular breeding.