Rippa Sonia, Adenier Hervé, Derbaly Michel, Béven Laure
Université de Technologie de Compiègne, CNRS, UMR 6022 Génie Enzymatique et Cellulaire, Compiègne Cedex, France.
Chem Biodivers. 2007 Jun;4(6):1360-73. doi: 10.1002/cbdv.200790116.
The plant-metabolic response to amphipathic peptides produced by the soil fungi of the genus Trichoderma remains largely unknown. The present investigation was undertaken to examine the death process in alamethicin-treated Arabidopsis thaliana plantlets. The rapid death triggered by alamethicin (at 50 microM) was shown to be associated with protein-synthesis arrest and with specific cleavage of 18S and 25S ribosomal RNA. The use of an inhibitor of nitric oxide (NO) synthases and of an NO scavenger suggested that rRNA cleavage was suppressed by NO. Experiments conducted with a synthetic alamethicin analogue, in which all alpha-aminoisobutyric acid (Aib) residues have been replaced by leucine moieties, showed that the non-coded residues are essential for the ability of the peptaibol to induce rRNA cleavage in Arabidopsis. Our data indicate that further investigations on the mode of action of alamethicin in planta could be of great interest to study the death-signaling pathway associated with rRNA degradation in plants.
植物对木霉属土壤真菌产生的两亲性肽的代谢反应在很大程度上仍不清楚。本研究旨在研究阿拉霉素处理的拟南芥幼苗的死亡过程。结果表明，阿拉霉素（50微摩尔）引发的快速死亡与蛋白质合成停滞以及18S和25S核糖体RNA的特异性切割有关。使用一氧化氮（NO）合酶抑制剂和NO清除剂表明，NO可抑制rRNA切割。用一种合成的阿拉霉素类似物进行的实验表明，在该类似物中所有α-氨基异丁酸（Aib）残基均已被亮氨酸部分取代，结果显示非编码残基对于该肽菌素在拟南芥中诱导rRNA切割的能力至关重要。我们的数据表明，进一步研究阿拉霉素在植物中的作用方式可能对于研究与植物中rRNA降解相关的死亡信号通路具有重要意义。
