Graduate School of Life and Environmental Sciences; Kyoto Prefectural University; Kyoto, Japan.
Plant Signal Behav. 2013 Apr;8(4):e23603. doi: 10.4161/psb.23603. Epub 2013 Jan 18.
Chloroplasts are responsible for biosynthesis of salicylic acid (SA) an important signal molecule in plant immunity. EDS5 is a homolog of the MATE (multidrug and toxic compound extrusion) family of transporters, and is essential for SA biosynthesis. It has been speculated that EDS5 would be involved in the export of SA from chloroplasts. However, the subcellular localization of EDS5 remains largely uncharacterized. We demonstrate here that EDS5 is specifically localized to the chloroplast envelope membrane in Arabidopsis. In addition, we found that EDS5 is preferentially expressed in epidermal cells. These findings suggest that EDS5 is responsible for transport of SA from chloroplasts to the cytoplasm in epidermal cells.
叶绿体负责生物合成水杨酸（SA），这是植物免疫中的一种重要信号分子。EDS5 是多药和毒性化合物外排（MATE）家族转运蛋白的同源物，是 SA 生物合成所必需的。人们推测 EDS5 可能参与 SA 从叶绿体的输出。然而，EDS5 的亚细胞定位在很大程度上仍未被阐明。我们在这里证明，EDS5 特异性定位于拟南芥的叶绿体被膜上。此外，我们发现 EDS5 在表皮细胞中优先表达。这些发现表明，EDS5 负责将 SA 从叶绿体运输到表皮细胞的细胞质中。
