Previous studies have revealed that the INDUCER OF CBF EXPRESSION (ICE)–CREPEAT BINDING FACTOR/DRE BINDING FACTOR1 (CBF/DREB1) transcriptional cascade plays a critical role in the cold-response pathways in Arabidopsis thaliana. Dissecting crucial upstream regulatory signals or components of the ICE-CBF/DREB1 cascade will enhance the understanding of plant cold-tolerance mechanisms.
The plant hormone jasmonate is ubiquitous in the plant kingdom and is required for regulation of multiple physiological processes. Although jasmonate has been implicated in cold storage of several tropical and subtropical fruits, the exact role played by jasmonate in mediating freezing responses and the molecular mechanisms of these regulatory responses remain to be elucidated.
Prof. YU Diqiu and his team of Xishuangbanna Tropical Botanical Garden (XTBG) conducted a study to investigate jasmonate’s role in freezing stress in Arabidopsis by examining the effect of exogenous application of jasmonate on plant freezing tolerance, the effect of impaired jasmonate biosynthesis and signaling on freezing stress, and the changes in endogenous jasmonate levels in response to cold.
Their results demonstrated that jasmonate had a positive role in both constitutive and cold acclimation–induced freezing tolerance of Arabidopsis. Treating wild-type plants with exogenous MeJA significantly enhanced tolerance to freezing stress. By contrast, blocking endogenous jasmonate biosynthesis and signaling conferred decreased freezing tolerance under both nonacclimated and cold-acclimated conditions. Furthermore, endogenous jasmonate production was triggered by cold treatment. The researchers therefore concluded that jasmonate positively regulated Arabidopsis constitutive and cold acclimation–induced freezing tolerance.
The work was supported by the Natural Science Foundation of China (U1202264 and 31171183) and the Science Foundation of the Chinese Academy of Sciences (KSCX3-EW-N-07 and the CAS 135 program XTBG-F04).