Studies of early stages of cucumber green mottle mosaic virus (CGMMV) disease have been recently focused on plant molecular responses. However, extreme diurnal environmental temperatures, characteristic of global climate changes, could affect plant susceptibility and disease phenotype progression. Our studies of CGMMV disease progression, under simulated extreme temperature waves, have revealed two new disease initiation phenotypes that developed gradually, preceding severe symptom manifestations of post-recovery CGMMV systemic infections. 'Early post-recovery stage' bright yellow islands (BYIs) with defined boundaries amid asymptomatic leaf blades were first emerging followed by 'late post-recovery stage' BYIs with diffused boundaries. A deduced CGMMV disease progression scheme, postulating BYI symptom occurrence time-windows, revealed BYIs in field grown cucumber plants exposed to extreme diurnal temperatures. Profiling ontology of cucumber differentially expressed genes in BYIs vs the associated dark-green surrounding tissues disclosed activation of jasmonic acid (JA) pathway in 'early post-recovery stage' BYIs. JA signaling was inactivated in 'late post-recovery stage' BYIs concomitant with increasing expressions of JA signaling inhibitors and downregulation of JA responsive phenylpropanoid pathway. Our results disclosed a new phenotypic description of CGMMV disease initiation, characteristic of cucumbers grown under extreme environmental temperature fluctuations. The BYI phenotypes could define a time-window for CGMMV disease management applications.

对黄瓜绿色斑驳花叶病毒 (CGMMV) 病害早期的研究最近集中在植物分子反应上。然而，作为全球气候变化特征的极端昼夜环境温度可能会影响植物的易感性和疾病表型进展。我们在模拟极端温度波下对 CGMMV 疾病进展的研究揭示了两种新的疾病起始表型，它们逐渐发展，先于恢复后 CGMMV 全身感染的严重症状表现。在无症状叶片中具有明确边界的“早期恢复阶段”亮黄色岛 (BYI) 首先出现，然后是具有扩散边界的“后期恢复阶段”BYI。推导出的 CGMMV 疾病进展方案，假设 BYI 症状发生时间窗口，揭示暴露于极端昼夜温度的田间黄瓜植株的 BYI。BYI中黄瓜差异表达基因的分析本体与相关的深绿色周围组织相比，茉莉酸 (JA) 通路在“早期恢复阶段”BYIs 中被激活。JA 信号在“后期恢复阶段”BYIs 中失活，伴随着 JA 信号抑制剂的表达增加和 JA 响应性苯丙烷途径的下调。我们的结果揭示了 CGMMV 疾病起始的新表型描述，这是在极端环境温度波动下生长的黄瓜的特征。BYI 表型可以为 CGMMV 疾病管理应用定义一个时间窗口。