Transcriptional and metabolite analysis reveal a shift in fruit quality in response to calcium chloride treatment on "Kyoho" grapevine.

'Kyoho' grapevine () treated by calcium ions solution has been proved as an effective treatment to extend grape quality during storage to reduce disease, but its molecular mechanism was not clear yet. In the current work, grape berries were treated with different concentration of Calcium chloride (CaCl) solution, and their effects on antioxidant enzyme activity and transcriptome and metabolome in fruit were investigated. CaCl treatments reduced weight loss and inhibited the decrement of flesh firmness. 80 mM CaCl significantly increased the activity of antioxidant enzymes POD, SOD and CAT, which was the optimum experimental concentration. The study showed that the expression level of heat shock transcription factor and UBX which involved in endoplasmic reticulum stress and degradation pathway increased significantly. Moreover, the corresponding metabolites, such as heat shock protein and organic acid, also increased significantly. The misfolded proteins are transported to the cytosol for degradation, so that the preservation ability of grape is improved.