Pear dormancy release modulated by the phytohormone crosstalk between BR and JA signaling pathways

Bud dormancy is an important physiological process during severe winter and its release requires a period of chilling accumulation. In pear, after a period of chilling accumulation, exogenous gibberellic acid (GA₄₊₇) treatments promoted dormancy release, indicating that exogenous GA could promote the release of pear dormancy. The function of brassinosteroids (BRs) and jasmonic acids (JAs) in dormancy release has received less attention, and the underlying mechanism remains uncharacterized. This study revealed a new model of crosstalk between BR and JA signaling in pear dormancy release. First, we found that at a certain chilling accumulation, both 24-epibrassinolide (EBR) and methyl jasmonate (MeJA) positively regulated dormancy release. Furthermore, MeJA treatment significantly promoted the BR signaling pathway genes expression. In addition, both EBR and MeJA treatment can positively increased the expression levels of GA biosynthetic genes. In conclusion, our data elucidate a new model for dormancy release involving the amelioration of insufficient chilling accumulation by the BR- and JA-induced GA biosynthetic pathways.