Role of jasmonate signaling pathway in resistance to dehydration stress in Arabidopsis

The plant hormone jasmonic acid (JA) is critical to plant defense and plant development. Various studies have focused on the regulation of plant biotic stress by JA, but few have assessed its roles in abiotic stress. This study investigated the components of the JA signaling pathway in its response to dehydration stress. coi1-2, 35Spro:JAZ1-ΔJas and myc2-2 mutants disrupted in key regulators of JA signaling were more sensitive to dehydration stress. This suggests that JA signaling plays a key role in resistance to dehydration. Furthermore, we found that the mediation of the dehydration process by JA occurs via the induction of ERD1 expression. And our genetic data showed that ERD1 acts as a positive factor in dehydration stress. The bHLH transcription factor MYC2 could bind to the promoter of its target gene ERD1 and activate its expression to activate the JA-induced response to dehydration stress. Genetic and molecular data indicate that ERD1 functions downstream of the JA-mediated signaling pathway in response to dehydration stress. Our study, thus, reveals the following JA-mediated dehydration signaling pathway: the receptor COI1 perceives the dehydration signal, after which the signal is transmitted to MYC2, which then binds to the promoter of ERD1 and induce its expression. MYC2-induced ERD1 expression then enhances the resistance to dehydration stress. Together, our data strongly suggest a role for the JA signaling pathway in response to dehydration stress.