TOO MUCH LOVE, a Novel Kelch Repeat-Containing F-box Protein, Functions in the Long-Distance Regulation of the Legume-Rhizobium Symbiosis
TOO MUCH LOVE, a Novel Kelch Repeat-Containing F-box Protein, Functions in the Long-Distance Regulation of the Legume-Rhizobium Symbiosis
复制标题
DOI：
10.1093/pcp/pct022
复制
发表时间：
2013-04-01
影响因子：
4.9
通讯作者：
Kawaguchi, Masayoshi
中科院分区：
文献类型：
--
作者：
Takahara, Masahiro;Magori, Shimpei;Kawaguchi, Masayoshi
豆科植物与统称为根瘤菌的固氮细菌的相互作用导致根瘤的发育。结节形成的数量通过宿主的系统负反馈控制被严格限制，称为自动调节（AON）。在这里，我们报告的表征和基因鉴定太多的爱（TML），一个根因子，在AON的模式豆科植物百脉根。在我们的遗传分析中，使用另一个根调节的过度增殖突变体，丰富，tml-1丰富的双突变体表现出加性效应的结节数，而tml-1的har 1 -7双突变体没有，这表明TML和PLENTY在不同的遗传途径，TML和HAR 1在相同的遗传途径中发挥作用。在tml突变体背景中未观察到CLE-RS 1/RS 2过表达对结节形成的系统性抑制，表明TML作用于CLE-RS 1/RS 2的下游。tml-1 Snf 2双突变体产生了过多的自发结节，表明TML抑制结节器官发生。结合tml-1/-2/-3缺失区的确定、tml-4的精细定位和下一代测序分析，我们鉴定了含Kelch重复序列的F-box蛋白中的无义突变。由于候选基因的基因敲低大大增加了结节的数量，我们得出结论，它应该是致病基因。表达分析表明，TML是一个根特异性基因。此外，ProTML-GUS的活性组成型检测在根尖和根瘤/根瘤原基根瘤菌感染后。总之，TML是一个根本因素，作用于AON的最后阶段。
The interaction of legumes with N-2-fixing bacteria collectively called rhizobia results in root nodule development. The number of nodules formed is tightly restricted through the systemic negative feedback control by the host called autoregulation of nodulation (AON). Here, we report the characterization and gene identification of TOO MUCH LOVE (TML), a root factor that acts during AON in a model legume Lotus japonicus. In our genetic analyses using another root-regulated hypernodulation mutant, plenty, the tml-1 plenty double mutant showed additive effects on the nodule number, whereas the tml-1 har1-7 double mutant did not, suggesting that TML and PLENTY act in different genetic pathways and that TML and HAR1 act in the same genetic pathway. The systemic suppression of nodule formation by CLE-RS1/RS2 overexpression was not observed in the tml mutant background, indicating that TML acts downstream of CLE-RS1/RS2. The tml-1 Snf2 double mutant developed an excessive number of spontaneous nodules, indicating that TML inhibits nodule organogenesis. Together with the determination of the deleted regions in tml-1/-2/-3, the fine mapping of tml-4 and the next-generation sequencing analysis, we identified a nonsense mutation in the Kelch repeat-containing F-box protein. As the gene knockdown of the candidate drastically increased the number of nodules, we concluded that it should be the causative gene. An expression analysis revealed that TML is a root-specific gene. In addition, the activity of ProTML-GUS was constitutively detected in the root tip and in the nodules/nodule primordia upon rhizobial infection. In conclusion, TML is a root factor acting at the final stage of AON.