To better understand the cold-induced regulation of scald-like disorders in pears and the specific roles played by ethylene and α-farnesene, three pear cultivars with different patterns of ethylene production and chilling requirement were used in this study. Fruit were treated with 1-MCP (ethylene inhibitor) and Lovastatin (α-farnesene inhibitor) and stored at -0.5 °C and 90 % RH during 6 months. Changes in targeted metabolites, enzymes and genes were monitored periodically up to 120 d of storage and superficial scald incidence was assessed after this time and after 180 d of cold storage. 1-MCP treatment induced in the three cultivars a down-regulation of PcACS1, PcACO1, PcERF1 and PcAFS1 gene expression, but also a significant up-regulation of PcETR1 and PcEIN2 that led in all cases to the inhibition of the disorder incidence. In contrast, Lovastatin treatment caused diverse molecular or biochemical responses depending on the cultivar. In ‘Blanquilla’ pears, this treatment completely inhibited superficial scald reinforcing the idea that ethylene-α-farnesene interaction plays a decisive role in this specific cultivar. In contrast to 1-MCP, Lovastatin treatment did not control the disorder incidence in ‘Flor d’Hivern’ pears. Inversely, 1-MCP inhibited the development of the disorder, showing then that the inhibition of ethylene biosynthetic and signalling pathway may control superficial scald even in cultivars producing very low or undetectable ethylene levels. Finally, the inefficacy of both treatments to prevent the disorder development in ‘Conference’ pears, suggests the existence of a disorder different from that observed for the other cultivars whose biochemical basis remain unknown. Collectively our results show that the regulatory processes triggered by cold stress in pears are complex and cultivar dependent.

为了更好地理解冷诱导的梨性烫伤样疾病的调控以及乙烯和α-法呢烯的特殊作用，本研究使用了三种乙烯生产方式和冷藏需求不同的梨品种。将果实用1-MCP（乙烯抑制剂）和Lovastatin（α-法呢烯抑制剂）处理，并在-0.5°C和90％RH下保存6个月。定期监测目标代谢物，酶和基因的变化，直至存储120 d，然后在此时间之后和冷藏180 d后评估表面烫伤的发生率。1-MCP处理在三个品种中诱导了PcACS1，PcACO1，PcERF1和PcAFS1的下调基因表达，但也显着上调PcETR 1和PcEIN2在所有情况下都导致了对疾病发病率的抑制。相比之下，洛伐他汀治疗会根据品种而引起多种分子或生化反应。在'Blanquilla'梨中，这种处理方法完全抑制了表皮烫伤，增强了乙烯-α-法呢烯相互作用在该特定品种中起决定性作用的想法。与1-MCP相反，洛伐他汀治疗不能控制'Flor d'Hivern'梨的失调发生率。相反，1-MCP抑制了疾病的发展，这表明即使在产生非常低或无法检测到的乙烯水平的品种中，对乙烯生物合成和信号传导途径的抑制也可能控制表皮鳞屑。最后，两种治疗方法均无法有效预防“会议”梨的疾病发展，这表明存在一种不同于其他生化基础仍未知的品种所观察到的疾病。总的来说，我们的结果表明，梨的冷胁迫触发的调控过程是复杂的，并且依赖于品种。