Deng Bing, Li Qingxiu, Liang Liya, Zhang Hongyan, Zhang Xiaoyu
College of Food Science and Engineering, Shanxi Agricultural University, Taigu 030801, China.
College of Food Science and Biological Engineering, Tianjin Agricultural University, Tianjin 300392, China.
Foods. 2025 Jun 18;14(12):2132. doi: 10.3390/foods14122132.
This study investigated the impact of slow cooling on browning and fruit quality at three maturity stages (early, mid and late). Slow cooling reduced core browning in early/mid-harvest pears, as the browning indexes of early-, middle- and late-harvested 'Yali' pears at 60 d were 0.13, 0 and 0.1, respectively, preserving firmness and soluble solids. Transcriptomic analysis revealed that upregulated genes in 'Yali' pears facilitated stress adaptation via enhanced catalytic activity and phosphorylation. Mid-harvested pears exhibited activation of phosphorus metabolism and DNA repair mechanisms to maintain cellular homeostasis, whereas the late-harvested counterparts showed significant suppression of photosynthesis-related pathways and pyrimidine metabolism, which collectively accelerated senescence progression. Universal downregulation of hormone-response pathways such as ethylene and auxin revealed systemic stress adaptation decline. Then, the PbRAV transcription factors' role was also studied. EMSA confirmed that GST-PbRAV2 binds to the PbLAC15 promoter, linking RAV2 to laccase regulation. Overripe pears showed PbRAV2 dysregulation, impairing LAC15 suppression and accelerating browning. Findings provide a theoretical basis for using slow cooling to mitigate browning in pear storage.
本研究调查了缓慢冷却对三个成熟阶段（早期、中期和晚期）梨果实褐变和品质的影响。缓慢冷却减少了早/中期采收梨的果心褐变，因为早采、中采和晚采‘鸭梨’在60天时的褐变指数分别为0.13、0和0.1，同时保持了果实硬度和可溶性固形物含量。转录组分析表明，‘鸭梨’中上调的基因通过增强催化活性和磷酸化促进了胁迫适应。中期采收的梨表现出磷代谢和DNA修复机制的激活以维持细胞内稳态，而晚期采收的梨则显示出光合作用相关途径和嘧啶代谢的显著抑制，这共同加速了衰老进程。乙烯和生长素等激素响应途径的普遍下调表明系统胁迫适应能力下降。此外，还研究了PbRAV转录因子的作用。电泳迁移率变动分析证实GST-PbRAV2与PbLAC15启动子结合，将RAV2与漆酶调控联系起来。过熟梨显示出PbRAV2失调，损害了对LAC15的抑制并加速了褐变。研究结果为利用缓慢冷却减轻梨贮藏期间的褐变提供了理论依据。
