‘Starkrimson’ pears are prone to develop scald-like disorders after cold storage. In contrast, ‘Conference’ pears are less susceptible to scald-like disorders. In the present study, the scald morphology and underlying mechanism related to scald formation in ‘Starkrimson’ fruit and ‘Conference’ fruit were investigated. The scald-like symptoms in the two pear varieties were different from typical superficial scald in pears. In ‘Starkrimson’ fruit, the scald morphology was similar to soft scald symptoms, and the scald disorder could be inhibited by 1-MCP treatment but not triggered by oxidation of α-farnesene. In ‘Conference’ fruit, the occurrence of scald-like symptoms was accompanied by fruit senescence. To elucidate the scald formation mechanism in the two cultivars, scald incidence, membrane integrity, PPO activities, laccase activities and phenolic compositions were evaluated in peel tissue of ‘Starkrimson’ and ‘Conference’. The cell membrane integrity related parameters including malondialdehyde (MDA) contents and relative leakage rates (RLR) gradually increased accompanying scald development in both cultivars. However, higher level of MDA contents and RLR but less scald symptom was observed in ‘Conference’ than those in ‘Starkrimson’. The enzymatic browning during scald development was further confirmed to be catalyzed by laccases but not PPO. Laccase activity and the expression pattern of PcTT10 (the typical enzymatic browning related laccase) were highly associated with scald development. Moreover, the native phenolic compounds in ‘Starkrimson’ could cause more severe enzymatic browning than that in ‘Conference’. Taken together, our results indicated although cell membrane integrity and laccase participated in scald formation in pear fruit, variable phenolic composition in different pear cultivars may contribute to their different susceptibility to scald.

“Starkrimson”梨在冷藏后容易出现烫伤样疾病。相比之下，“会议”梨不太容易患烫伤样疾病。在本研究中，研究了“Starkrimson”果实和“Conference”果实中与烫伤形成相关的烫伤形态和潜在机制。两个梨品种的烫伤样症状与梨典型的表浅烫伤不同。在'Starkrimson'果实中，烫伤形态类似于软烫伤症状，烫伤障碍可以通过1-MCP处理而得到抑制，但不会由α-法呢烯氧化引发。在'会议'果实中，烫伤样症状的发生伴随着果实衰老。阐明两个品种的烫伤形成机制，烫伤发生率，膜完整性，PPO活性，在“Starkrimson”和“Conference”的果皮组织中评估漆酶活性和酚类成分。随着两个品种的烫伤发展，包括丙二醛（MDA）含量和相对渗漏率（RLR）在内的细胞膜完整性相关参数逐渐增加。然而，与“Starkrimson”相比，“会议”中的 MDA 含量和 RLR 水平更高，但烫伤症状更少。进一步证实烫伤发展过程中的酶促褐变是由漆酶而非 PPO 催化的。漆酶活性和表达模式 然而，与“Starkrimson”相比，“会议”中的 MDA 含量和 RLR 水平更高，但烫伤症状更少。进一步证实烫伤发展过程中的酶促褐变是由漆酶而非 PPO 催化的。漆酶活性和表达模式 然而，与“Starkrimson”相比，“会议”中的 MDA 含量和 RLR 水平更高，但烫伤症状更少。进一步证实烫伤发展过程中的酶促褐变是由漆酶而非 PPO 催化的。漆酶活性和表达模式PcTT10（典型的酶促褐变相关漆酶）与烫伤发展高度相关。此外，“Starkrimson”中的天然酚类化合物可能会导致比“会议”中更严重的酶促褐变。总之，我们的结果表明，尽管细胞膜完整性和漆酶参与了梨果实的烫伤形成，但不同梨品种中不同的酚类成分可能导致它们对烫伤的不同敏感性。