Analysis of temporal expression of SymRK on infection signaling system in the nodulation

Abstract

   When rhizobia accept flavonoids secreted by host legumes, they synthesize and secrete Nod factors. A nodule formation signal transduction model has been proposed in which the host plant responds to this Nod factor and is linked to phenomena such as ion influx, calcium spiking, root hair deformation, and infection thread formation. In this study, we analyzed the expression of SymRK, which is considered to be a related gene due to rhizobial infection during the initial infection process in nodule formation. As a result, the expression peak of SymRK was observed 5 minutes after infection. This fast reaction time is due to the fact that in the initial response of the Nod factor, intracellular alkalization reacts with the Nod factor and occurs in several tens of seconds, and then the activation of the cytokinin synthesis gene occurs in about 1 minute after infection. Activity of SymRK is thought to be induced after these processes.