Autophagy is important for cell survival during stress and nutrient recycle. However, the mechanisms involved in regulating autophagy in cucumber have not been determined. Here, we analyzed the transcript abundance of key autophagy genes in the conjugation pathway including ATG3, ATG4, ATG5, ATG7, ATG8, ATG10, ATG12 and ATG16 in response to nitrogen deficiency, pathogen infection and oxidative stress in Cucumis sativus. ATG8 protein abundance was analyzed using immunoblot analysis. Seven out of 13 autophagy genes studied have splice variances including ATG3, ATG4, ATG5, ATG8b, ATG8c, ATG8e and ATG10. All except ATG5 have changes in transcript variances abundance upon nitrogen starvation, indicating regulation via alternative splicing is pervasive in autophagy genes. This is the first report of alternative splicing in autophagy genes in cucumbers. However, transcription control is also important, especially in ATG4, and those without transcript variances. Moreover, different environment cues regulate autophagy genes through different mechanisms. The ATG8 protein tag was also regulated at the protein level through post-translational modification and blockage of degradation. This work shows that the regulation of autophagy in cucumber is complex and involves many mechanisms. Better understanding of autophagy regulation would thus help breeding plants that perform better even under environmental stresses.

自噬对于压力和营养循环过程中的细胞存活很重要。然而，黄瓜中调节自噬所涉及的机制尚未确定。在这里，我们分析了结合途径中关键自噬基因的转录本丰度，包括ATG3、ATG4、ATG5、ATG7、ATG8、ATG10、ATG12和ATG16，以响应黄瓜中的氮缺乏、病原体感染和氧化应激。使用免疫印迹分析分析 ATG8 蛋白丰度。所研究的 13 个自噬基因中有 7 个具有剪接变异，包括ATG3、ATG4、ATG5、ATG8b、ATG8c、ATG8e和ATG10。除ATG5外的所有在氮饥饿时转录变异丰度发生变化，表明通过可变剪接进行的调节在自噬基因中普遍存在。这是黄瓜自噬基因可变剪接的第一份报告。然而，转录控制也很重要，尤其是在ATG4和那些没有转录变异的情况下。此外，不同的环境线索通过不同的机制调节自噬基因。ATG8 蛋白质标签也通过翻译后修饰和降解阻断在蛋白质水平上进行调节。这项工作表明，黄瓜自噬的调控是复杂的，涉及多种机制。因此，更好地了解自噬调节将有助于培育即使在环境压力下也表现更好的植物。