, a root regulator associated with the long-distance control of nodulation in

Magori, Shimpei*; Kira, Erika*; Shibata, Satoshi*; Umehara, Yosuke*; Kochi, Hiroshi*; Hase, Yoshihiro; Tanaka, Atsushi; Sato, Shusei*; Tabata, Satoshi*; Kawaguchi, Masayoshi*

Legume plants tightly control the development and number of symbiotic root nodules. In , this regulation required in the shoots, suggesting that a long-distance communication between the shoots and the roots may exist. To better understand its molecular basis, we isolated and characterized a novel hypernodulating mutant of named (). Reciprocal grafting with wild type showed that hypernodulation is determined by the root genotype. Moreover, grafting a shoot onto a rootstock did not exhibit any obvious additive effects on the nodule number. These observations indicate that a shoot factor and a root factor participate in the same genetic pathway which governs the long-distance signaling of nodule number control. may function downstream of and the gene product might serve as a receptor or mediator of unknown mobile signal molecules that are transported from the shoots to the roots.