EgmiR5179 Regulates Lipid Metabolism by Targeting EgMADS16 in the Mesocarp of Oil Palm ().

, one of the MADS-box transcription factors in oil palm, has a high expression level in the late fruit development of the oil palm fruit mesocarp. At the same time, it is also predicted to be the target gene of which has been identified in previous research. In this paper, we focused on the function and regulatory mechanism of the gene in oil palm lipid metabolism. The results indicated that the transcription level of was highest in the fourth stage, and a dual-luciferase reporter assay proved that the expression level was downregulated by . In both the OX seeds and oil palm embryonic calli, the total lipid contents were significantly decreased, but the contents of C18:0 and C18:3 in OX lines were significantly increased. As expected, EgmiR5179 weakened the inhibitory effect of on the oil contents in transgenic plants that coexpressed and (OXEgmiR5179-). Moreover, yeast two-hybrid and BiFC analyses suggested that there was an interaction between the protein and EgGLO1 protein, which had been proven to be capable of regulating fatty acid synthesis in our previous research work. In summary, a model of the molecular mechanism by which miRNA5179 targets to regulate oil biosynthesis was hypothesized, and the research results provide new insight into lipid accumulation and molecular regulation in oil palm.