Fig fruit firmness decreases rapidly during ripening and after harvest, resulting in poor storability and transportation loss, which severely restricts development of the fresh fig industry. APETALA2/ethylene-responsive factor (AP2/ERF) transcription factors are downstream components of the ethylene-signaling pathway that play crucial roles in quality formation during fruit ripening. In this study, (Fc) ERF12 was clustered in repressor subfamily VIII of ERFs through phylogenetic analysis, and further recruited by its two EAR motifs and expression pattern during fig ripening. DNA affinity purification sequencing analysis indicated that FcERF12 binds to the promoter or gene body regions of multiple ripening-related genes, including cell wall-modification genes , and , and ethylene-biosynthesis genes and . Yeast two-hybrid assay demonstrated that FcERF12 interacts with TOPLESS (TPL) co-repressors FcTPL1, FcTPL4 and FcTPL5, and histone deacetylases FcHDA6 and FcHDA19; interaction with FcTPL4 and FcTPL5 relied on the C-terminal EAR motif. Overexpressing in tomato did not change fruit size or yield, but resulted in an 18.37% increment in fruit firmness and a 49.62% reduction in ethylene-release rate at fruit ripening, accompanied by a significant decrease in seed number per fruit. Transcriptomic analysis revealed downregulation of tomato cell wall-modification genes , and , and ethylene-synthesis genes and . Metabolomic profiling identified 82 differentially accumulated flavonoid metabolites, 61 of them showing significantly decreased contents. Taken together, our results exhibit the negative regulatory role of FcERF12 in fig ethylene-signal transduction, providing new information on precise control of fruit firmness and other quality traits at ripening.

中文翻译：

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无花果 ERF12 提高果实成熟时的硬度


无花果果实在成熟过程中和采后硬度迅速下降，耐贮性差，运输损失大，严重制约了无花果鲜食产业的发展。 APETALA2/乙烯反应因子 (AP2/ERF) 转录因子是乙烯信号通路的下游成分，在果实成熟过程中的品质形成中发挥着至关重要的作用。在本研究中，通过系统发育分析，(Fc) ERF12 聚集在 ERF 的阻遏子亚家族 VIII 中，并通过其两个 EAR 基序和无花果成熟过程中的表达模式进一步招募。 DNA亲和纯化测序分析表明FcERF12与多个成熟相关基因的启动子或基因体区域结合，包括细胞壁修饰基因、和、乙烯生物合成基因和。酵母双杂交测定表明 FcERF12 与 TOPLESS (TPL) 共阻遏物 FcTPL1、FcTPL4 和 FcTPL5 以及组蛋白脱乙酰酶 FcHDA6 和 FcHDA19 相互作用；与 FcTPL4 和 FcTPL5 的相互作用依赖于 C 端 EAR 基序。在番茄中过度表达不会改变果实大小或产量，但导致果实硬度增加 18.37%，果实成熟时乙烯释放率降低 49.62%，同时每个果实的种子数量显着减少。转录组分析显示番茄细胞壁修饰基因 、 和 、以及乙烯合成基因 和 的下调。代谢组学分析鉴定出 82 种差异积累的类黄酮代谢物，其中 61 种显示出含量显着降低。综上所述，我们的结果展示了 FcERF12 在无花果乙烯信号转导中的负调节作用，为精确控制果实硬度和成熟时其他品质性状提供了新信息。