Record ID No. |
2488 |
Author(s) |
Hayashi T., Banba M., Shimoda Y., Kouchi H., Hayashi M., Imaizumi-Anraku H. , 2010 |
Affiliation |
National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8602, Japan. onko@affrc.go.jp |
Title |
A dominant function of CCaMK in intracellular accommodation of bacterial and fungal endosymbionts |
Source. Vol.(no):Page |
Plant Journal. 63(1):141-154p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Biological Interaction |
Sub-subjects |
Nodule forming nitrogen fixers |
Host |
Legumes |
Organism |
Arbuscular mycorrhiza, Rhizobium |
Country |
Japan, East Asia |
Abstracts |
In legumes, Ca2+/calmodulin-dependent protein kinase (CCaMK) is a component of the common symbiosis genes that are required for both root nodule (RN) and arbuscular mycorrhiza (AM) symbioses and is thought to be a decoder of Ca2+ spiking, one of the earliest cellular responses to microbial signals. A gain-of-function mutation of CCaMK has been shown to induce spontaneous nodulation without rhizobia, but the significance of CCaMK activation in bacterial and/or fungal infection processes is not fully understood. Here we show that a gain-of-function CCaMKT265D suppresses loss-of-function mutations of common symbiosis genes required for the generation of Ca2+ spiking, not only for nodule organogenesis but also for successful infection of rhizobia and AM fungi, demonstrating that the common symbiosis genes upstream of Ca2+ spiking are required solely to activate CCaMK. In RN symbiosis, however, CCaMKT265D induced nodule organogenesis, but not rhizobial infection, on Nod factor receptor (NFRs) mutants. We propose a model of symbiotic signaling in host legume plants, in which CCaMK plays a key role in the coordinated induction of infection thread formation and nodule organogenesis. |