Evaluation of dry and wet storage on vase quality of cut peony based on the regulation of starch and sucrose metabolism

Abstract

Herbaceous peony (Paeonia lactiflora Pall.) is one of the most important cut flowers worldwide, but the short natural florescence seriously affects its industrial development. In this study, the cut peony ‘Yang Fei Chu Yu’ was preserved in dry storage (DS) and wet storage (WS), respectively, at 0–4 °C. We set two treatments of short- and long-term storage (S-tS, 3 d; L-tS, 23 d). We assessed the postharvest performance; determined the changes in starch, sucrose, glucose, and fructose; and then analyzed the expression of a subset of representative genes that regulate starch and sucrose metabolism by RT-qPCR. When compared to WS, our results indicated that DS treatment exhibited significantly higher vase quality of cut peony after both S-tS and L-tS. For S-tS, this effect should be due to faster starch consumption during storage of 1–3 d and sucrose hydrolysis at the beginning of the vase period. The change in starch hydrolysis can be attributed to increased expression of PlSPS1 and PlSPS4 as well as decreased expression of PlSUS4, whereas the sucrose metabolism should be associated with the inducing of PlSUS3 expression. During S-tS, PlCWIN1 may positively and PlVIN1 may negatively affect vase quality by adjusting water use efficiency. Inducing expression of PlCIN1 and PlCIN2 may also improve cut flower quality, probably via other pathways. For L-tS, the higher level of glucose and fructose content at the end of the period may be more beneficial in improving vase quality. The increasing expression of PlSUS3 and the decreasing expression of PlVIN1 as well as the inducing expression of the three PlCINs may regulate this process at the transcriptional level. Based on these results, we recommend that DS is used for cut peony cold storage within a prescribed period, regardless of the storage time.