Identification and Functional Exploration of the ALKBH Gene Family in Oriental Melon Fruit Ripening

N6-methyladenosine (m⁶A) methylation functions as a vital post-transcriptional and epigenetic modification in higher plants regulated by α-ketoglutarate-dependent dioxygenases (ALKBH). However, the role of ALKBH genes in oriental melon (<i>Cucumis melo</i> L.) fruit ripening has not been explored. Therefore, we treated oriental melon with an exogenous m⁶A demethylase inhibitor (mechlorfenamic acid) then analyzed endogenous ethylene production and ripening-related indicators to explore the effects of m⁶A methylation on ripening. Bioinformatics and real-time quantitative PCR analyses were used to determine the impact of <i>ALKBH</i> genes on key ethylene synthesis gene expression. Treatment effectively inhibited endogenous ethylene production, firmness changes, and soluble solid contents, thereby extending fruit ripening. Eight <i>ALKBH</i> gene family members belonging to five major groups were identified in the melon genome. All members were expressed in ripening fruits, with different expression patterns during ripening. <i>CmALKBH6</i>, <i>CmALKBH7</i>, and <i>CmALKBH8</i> expression was inhibited by an ethylene inhibitor (1-methylcyclopropene). The transient overexpression (OE) of <i>CmALKBH8</i> in oriental melon led to the increased expression of the ethylene synthesis genes <i>CmACS1</i>, <i>CmACS2</i>, and <i>CmACO1</i>. In summary, the ethylene-regulated gene <i>CmALKBH8</i> may participate in oriental melon fruit ripening regulation by modulating the methylation levels of ethylene synthesis-related genes. These findings help us better understand how m⁶A methylation regulates melon ripening.