中文摘要：

新兴的证据证明了 ROP GTPases 在共生起重要作用，但是他们在共生的规定上的分子的机制大部分是未知的。在这研究，我们证明 MtROP8 涉及在 Medicago truncatula 和 Sinorhizobium meliloti 之间的共生相互作用。表示分析证明 MtROP8 在早感染的根是下面调整的，但是在与根相比的小瘤显著地起来调整。 RNA 干扰( RNAi )的 Phenotypic 分析调停了 MtROP8 的 silencing 揭示了那 MtROP8 击倒表示导致了根头发的各种各样的发展缺点包括分叉的头发，短球状的根头发，和有明显的肿的底的甚至根头发，它被分发的修正和反应的氧种类( ROS )的层次引起。而且，感染事件在响应 S 怀有 MtROP8 RNAi 构造的转基因的根被增加。meliloti 接种，有提高的生节的伴随物。这些结果显示 MtROP8 由调整 ROS 生产和分发参予根头发开发和共生相互作用的建立。

英文摘要：

Emerging evidence has demonstrated that ROP GTPases play important roles in symbiosis, but the molecular mechanisms on their regulation in symbiosis are largely unknown. In this study, we showed that MtROP8 is involved in the symbiotic interaction between Medicago truncatula and Sinorhizobium meliloti. Expression analyses showed that MtROP8 was down-regulated in the early infected roots, but significantly up-regulated in nodules compared to the roots. Phenotypic analysis of RNA inter- ference （RNAi）-mediated silencing of MtROP8 revealed that knock-down of MtROP8 expression resulted in various developmental defects of root hairs, including branched hairs, short bulbous root hairs, and even root hairs with apparent swollen bases, which were caused by the modi- fication of the distribution and the levels of reactive oxygen species （ROS）. Moreover, infection events were increased in transgenic roots harboring the MtROP8 RNAi construct in response to S. meliloti inoculation, concomitant with enhanced nodulation. These results indicate that MtROP8 participates in root hair development and the establishmentof the symbiotic interaction by regulating ROS production and distribution.