Constitutive Autophagy in Plant Root Cells
Constitutive Autophagy in Plant Root Cells
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DOI：
10.4161/auto.4158
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发表时间：
2007-07
期刊：
影响因子：
13.3
通讯作者：
K. Yano;Takao K Suzuki;Y. Moriyasu
中科院分区：
文献类型：
--
作者：
K. Yano;Takao K Suzuki;Y. Moriyasu
在之前的研究中，我们使用一种膜渗透性蛋白酶抑制剂E-64d，发现自噬在大麦和拟南芥的根细胞中组成性地发生。本研究在拟南芥中表达了一种由自噬相关蛋白AtAtg8和绿色荧光蛋白（GFP）组成的融合蛋白，以实现自噬体的可视化。我们首先证实了在营养充足的培养基中生长的幼苗的根细胞中存在具有GFP荧光的自噬体。随着根细胞的生长和分化，自噬体的数量发生了变化。在顶端分生组织附近的细胞中，几乎没有发现自噬体。然而，在延伸区存在少量但数量显著的自噬体。在细胞停止生长但开始形成根毛的分化区发现了更多的自噬体。此外，我们证实在饥饿条件下，自噬在拟南芥根细胞中被激活。当根尖在无蔗糖培养基中培养时，自噬体在伸长区和分化区数量增加，在靠近根尖分生组织的细胞中出现了大量自噬体。结果表明，植物根细胞的自噬不仅参与营养限制条件下的养分循环，还参与细胞生长和根毛形成。拟南芥根尖细胞组成性自噬与酵母自噬基因同源性的关系Y. Inoue， T. Suzuki， M. Hattori， K. Yoshimoto， Y. Ohsumi和Y. Moriyasu Plant Cell physil 2006；47:1641-52
In previous studies, using a membrane-permeable protease inhibitor, E-64d, we showed that autophagy occurs constitutively in the root cells of barley and Arabidopsis. In the present study, a fusion protein composed of the autophagy-related protein AtAtg8 and green fluorescent protein (GFP) was expressed in Arabidopsis to visualize autophagosomes. We first confirmed the presence of autophagosomes with GFP fluorescence in the root cells of seedlings grown on a nutrient-sufficient medium. The number of autophagosomes changed as the root cells grew and differentiated. In cells near the apical meristem, autophagosomes were scarcely found. However, a small but significant number of autophagosomes existed in the elongation zone. More autophagosomes were found in the differentiation zone where cell growth ceases but the cells start to form root hair. In addition, we confirmed that autophagy is activated under starvation conditions in Arabidopsis root cells. When the root tips were cultured in a sucrose-free medium, the number of autophagosomes increased in the elongation and differentiation zones, and a significant number of autophagosomes appeared in cells near the apical meristem. The results suggest that autophagy in plant root cells is involved not only in nutrient recycling under nutrient-limiting conditions but also in cell growth and root hair formation. Addendum to: AtATG Genes, Homologs of Yeast Autophagy Genes, are Involved in Constitutive Autophagy in Arabidopsis Root Tip Cells Y. Inoue, T. Suzuki, M. Hattori, K. Yoshimoto, Y. Ohsumi and Y. Moriyasu Plant Cell Physiol 2006; 47:1641-52