ABSTRACT Autophagy, which is one of the self-degradation systems, promotes intracellular zinc (Zn) recycling under Zn deficiency (−Zn) in plants. Therefore, autophagy defective plants show severe chlorosis under −Zn. Root is the plant organ which directly exposed to Zn deficient environment, however, in our recent study, −Zn symptom was prominently observed in leaves as chlorosis. Here, we conducted micrografting to determine which organ’s autophagic activities are important to suppress the −Zn induced chlorosis. Grafted plants that have autophagic activities only in roots or leaves were grown under −Zn and then compared chlorotic phenotypes among them. As a result, regardless of the autophagic activities in rootstocks, −Zn induced-chlorosis in leaves was occurred only when autophagy in scion was defective. This data indicates that Zn resupplied by autophagic degradation in root cells could not contribute to suppress the chlorosis in leaves. Thus, autophagy in the aerial part is critical for controlling −Zn induced-chlorosis in leaves. Taken together, along with our recently reported data, we conclude that the mechanism of Zn resupply by autophagic degradation is not systemic throughout the plant but rather a local system.

中文翻译：

---

非系统性叶片自噬对抑制锌饥饿诱导的萎黄病的重要性

摘要 自噬是一种自降解系统，可促进植物缺锌 (-Zn) 下的细胞内锌 (Zn) 循环。因此，自噬缺陷植物在 -Zn 下表现出严重的萎黄病。根是直接暴露于缺锌环境的植物器官，然而，在我们最近的研究中，-Zn 症状在叶子中显着观察为萎黄病。在这里，我们进行了显微移植以确定哪个器官的自噬活动对于抑制 -Zn 诱导的萎黄病很重要。仅在根或叶中具有自噬活性的嫁接植物在 -Zn 下生长，然后比较它们之间的褪绿表型。因此，不管砧木的自噬活性如何，只有当接穗自噬有缺陷时才会发生-Zn诱导的叶片萎黄。该数据表明，根细胞中自噬降解补充的锌不能抑制叶片的萎黄病。因此，地上部分的自噬对于控制 -Zn 诱导的叶片萎黄病至关重要。总之，连同我们最近报道的数据，我们得出结论，自噬降解重新供应锌的机制不是整个植物的系统性，而是局部系统。