Transcriptional analysis of the response of nectarine fruit to low-temperature stress in cold storage

Nectarine (Prunus persica var. nectarina) is a sub-tropical fruit tree with strong cold sensitivity. In this study, flesh of nectarine (Shuguang) was used to determine the difference in transcriptional data before and after chilling injury under storage. In addition, genes responses involved in nectarine acclimation to cold stress were also explored. Results of the current study showed that nectarine was found to be more susceptible to chilling injury during storage at 5°C than at 0°C, and differentially expressed genes (DEGs) were concentrated in the late stage of low-temperature storage where chilling injury symptoms appeared at the end of the experiment. The key genes related to low-temperature response were associated with post-harvest biological processes. DEGs were annotated on the metabolic pathways of cold regulation signal transduction, cold resistance physiological metabolism and cold resistance-related protein synthesis. Moreover, the expression of genes related to cold stress such as plant hormone signal transduction element such as Auxin-responsive protein, transcription factors responding to cold stress such as WRKY transcription factor and genes related to maintaining membrane stability and regulating physiological metabolism such as proline dehydrogenase was more pronounced when nectarine was stored at 5°C than at 0°C. Overall, these findings showed that alteration in chilling temperature has substantial impact on the transcription levels associated with cold resistance pathway during the low-temperature storage of nectarine and thus promotes chilling injury disorders in nectarine.