SlMsrB5 contributes to the chilling tolerance induced by methyl jasmonate in postharvest tomato fruit

Chilling injury (CI) is a common phenomenon during low temperature storage for most fruits, reducing the effectiveness of refrigeration methods. Methyl jasmonate (MeJA) has been extensively employed to extend the shelf life of fruits during cold storage. However, the mechanism of MeJA inducing fruit resistance to CI requires further investigation. The study found that treating tomatoes with 0.05 mM MeJA inhibited CI by regulating the reactive oxygen species (ROS) metabolism, polyamines, and jasmonic acid (JA) signaling pathway, as well as cold response pathway. Interestingly, the expression of SlMsrB5 in tomato was up-regulated under MeJA treatment, showing an increase of 36.44% to 161.75% compared to the control fruit. Notably, silencing the expression of SlMsrB5 led to a continuously increased in CI incidence by 52.17% and CI index by 36.58% compared to the control fruit at the end of storage. Additionally, the silencing of SlMsrB5 weakened the inhibitory impact of MeJA on CI and reduced its induction effects on the aforementioned indicators. In addition, correlation analysis showed that the transcription of SlMsrB5 has a negative correlation with ROS related indicators under MeJA treatment, while was highly correlated with the aforementioned induction effects controlled by MeJA. Therefore, this study demonstrates a new basis for revealing the underlying mechanisms in the MeJA-regulated chilling resistance in postharvest fruits.