Methyl Jasmonate Enhances Ethylene Synthesis in Kiwifruit by Inducing Genes That Activate .

Cross-talk between various hormones is important in regulating many aspects of plant growth, development, and senescence, including fruit ripening. Here, exogenous ethylene (ETH, 100 μL/L, 12 h) rapidly accelerated 'Hayward' kiwifruit () softening and ethylene production and was enhanced by supplementing with continuous treatment with methyl jasmonate (MeJA, 100 μM/L, 12 h) (ETH+MeJA). ETH+MeJA enhanced ACC synthase (ACS) activities and 1-aminocyclopropane-1-carboxylic acid (ACC) accumulation but not ACC oxidase (ACO) activity. Increased transcripts of ACS genes and , ACS activity, and ethylene production were positively correlated. The abundance of was about 6-fold higher than . RNA-seq identified 6 transcription factors among the 87 differentially expressed unigenes induced by ETH+MeJA. Dual-luciferase and electrophoretic mobility shift assays (EMSA) indicated that AdNAC2/3 physically interacted with and trans-activated the promoter 2.2- and 3.5-fold, respectively. Collectively, our results indicate that MeJA accelerates ethylene production in kiwifruit induced by exogenous ethylene, via a preferential activation of and .