CLE-HAR1 systemic signaling and NIN-mediated local signaling suppress the increased rhizobial infection in the daphne mutant of Lotus japonicus
CLE-HAR1 systemic signaling and NIN-mediated local signaling suppress the increased rhizobial infection in the daphne mutant of Lotus japonicus
复制标题
CLE-HAR1 系统信号和 NIN 介导的局部信号抑制芫花突变体根瘤菌感染的增加
DOI：
10.1094/mpmi-08-19-0223-r
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
and Kawaguchi M.
中科院分区：
文献类型：
--
作者：
Yoro E.;Suzaki T.;and Kawaguchi M.
豆科植物在氮有限的土壤中通过与根瘤菌形成共生而生存。在根瘤共生过程中，豆科植物严格控制其共生器官--根瘤的发育，这一过程被称为根瘤自动调节（AON）。高血糖突变体的研究阐明了AON的分子基础。一些过度增殖突变体除了发育改变外，还表现出根瘤菌感染的增加。然而，AON与根瘤菌感染调控之间的关系尚未阐明。我们以前分离出ddaphne，一个非启动子（nin）等位基因突变体，在莲花。该突变体表现出显著增加根瘤菌感染，表明存在NIN介导的根瘤菌感染负调控。在此，我们研究了以前分离的AON组分，特别是CLAVATA 3/ESR（CLE）-再生根信号1（CLE-RS 1）、CLE-RS 2及其假定的受体超结和畸变根形成1（HAR 1）是否能够抑制daphnemutant中增加的感染。LjCLE-RS 1/2的组成型表达以HAR 1依赖的方式强烈地降低了在daphnemutant中的感染。此外，相互嫁接分析表明，强烈减少感染indaphnerrootstock组成型expressingLjCLE-RS 1被取消的接穗的har 1或klavier突变体，负责编码推定的LjCLE-RS 1受体的基因。这些数据表明，根瘤菌感染也是由CLE-HAR 1信号，AON的组成部分系统调节。此外，组成型表达的NINindaphne har 1双突变体根仅部分降低了根瘤菌的感染。我们的研究结果表明，先前确定的NIN介导的感染负调控涉及未知的局部信号，以及CLE-HAR 1长距离信号。
Legumes survive in nitrogen-limited soil by forming a symbiosis with rhizobial bacteria. During root nodule symbiosis, legumes strictly control the development of their symbiotic organs, the nodules, in a process known as autoregulation of nodulation (AON). The study of hypernodulation mutants has elucidated the molecular basis of AON. Some hypernodulation mutants show an increase in rhizobial infection in addition to developmental alteration. However, the relationship between the AON and the regulation of rhizobial infection has not been clarified. We previously isolateddaphne, anodule inception(nin) allelic mutant, inLotus japonicus. This mutant displayed dramatically increased rhizobial infection, suggesting the existence of NIN-mediated negative regulation of rhizobial infection. Here, we investigated whether the previously isolated components of AON, especially CLAVATA3/ESR (CLE)-RELATED-ROOT SIGNAL1 (CLE-RS1), CLE-RS2, and their putative receptor HYPERNODULATION AND ABERRANT ROOT FORMATION1 (HAR1), were able to suppress increased infection in thedaphnemutant. The constitutive expression ofLjCLE-RS1/2strongly reduced the infection in thedaphnemutant in a HAR1-dependent manner. Moreover, reciprocal grafting analysis showed that strong reduction of infection indaphnerootstock constitutively expressingLjCLE-RS1was canceled by a scion of thehar1orklaviermutant, the genes responsible for encoding putative LjCLE-RS1 receptors. These data indicate that rhizobial infection is also systemically regulated by CLE-HAR1 signaling, a component of AON. In addition, the constitutive expression ofNINindaphne har1double-mutant roots only partially reduced the rhizobial infection. Our findings indicate that the previously identified NIN-mediated negative regulation of infection involves unknown local signaling, as well as CLE-HAR1 long-distance signaling.