CNR Institute of Protein Biochemistry, via P. Castellino, 111, 80131 Naples, Italy.
Mol Biol Rep. 2011 Jun;38(5):2993-3000. doi: 10.1007/s11033-010-9964-x. Epub 2010 Feb 2.
Phytoplasmas are small (0.2-0.8 μm), wall-less, pleiomorphic prokaryotes responsible of numerous economically important plant diseases. They are characterized by a very small genome and are obligate parasites of phloem tissues and some insects that act as vectors of infection. To investigate molecular mechanisms involved in pathogenesis, the differential display technique was here applied to identify plant genes whose transcription was significantly altered in leaves of Madagascar periwinkle (Catharanthus roseus (L.) G.Don) infected by 'Candidatus Phytoplasma pyri'. We detected, reamplified, cloned, and sequenced 16 putative differentially expressed cDNA fragments. Northern blot analysis revealed that seven of the 16 genes identified were up-regulated following phytoplasma infection, while three genes were down-regulated. The remaining six genes did not show significant changes in the level of expression. Identified genes are mainly involved in plant defence/stress responses, protein metabolism and transport, transcriptional regulation, vesicle trafficking, and carbohydrate metabolism. The possible role played by these genes in the phytoplasma infection is discussed.
植原体是一类小（0.2-0.8μm）、无细胞壁、多形性的原核生物，可引起许多重要的植物病害。它们的基因组非常小，是韧皮部组织和一些作为感染介体的昆虫的专性寄生生物。为了研究致病过程中的分子机制，本研究采用差异显示技术来鉴定受‘黄脉病植原体（Candidatus Phytoplasma pyri）’感染的马缨丹（Catharanthus roseus (L.) G.Don）叶片中转录水平发生显著变化的植物基因。我们检测、重新扩增、克隆并测序了 16 个推定的差异表达 cDNA 片段。Northern blot 分析显示，在植原体感染后，16 个基因中有 7 个被上调，而 3 个基因被下调。其余 6 个基因的表达水平没有明显变化。鉴定出的基因主要参与植物防御/应激反应、蛋白质代谢和运输、转录调控、囊泡运输和碳水化合物代谢。讨论了这些基因在植原体感染中可能发挥的作用。
