Abstract: Formation of nitrogen fixing root nodules in legumes is induced by perception of lipochitin-oligosaccharide signal molecules secreted by compatible Rhizobium bacteria, which triggers a common symbiotic pathway. The present invention provides a spontaneous nodule formation (snf1-5g) mutant, in which the formation of symbiotic nodules is deregulated, leading to nodule development in the absence as well as in the presence of Rhizobium bacteria and/or exogenous rhizobial signals. The invention further provides an isolated DNA sequence encoding a mutant chimeric Ca2+/calmodulin dependent protein kinase whose activity results in this `gain of function? phenotype of spontaneous nodule formation. Furthermore the snf1-5g gene is shown to confer a spontaneous nodule formation phenotype to plants having a nodulation deficient genetic background.

Abstract: Formation of nitrogen fixing root nodules in legumes is induced by perception of lipochitin-oligosaccharide signal molecules secreted by compatible Rhizobium bacteria, which triggers a common symbiotic pathway. The present invention provides a spontaneous nodule formation (snf1-5g) mutant, in which the formation of symbiotic nodules is deregulated, leading to nodule development in the absence as well as in the presence of Rhizobium bacteria and/or exogenous rhizobial signals. The invention further provides an isolated DNA sequence encoding a mutant chimeric Ca2+/calmodulin dependent protein kinase whose activity results in this `gain of function? phenotype of spontaneous nodule formation. Furthermore the snf1-5g gene is shown to confer a spontaneous nodule formation phenotype to plants having a nodulation deficient genetic background.

Abstract: The present invention provides a Nod-factor binding element, comprising one or more NFR polypeptides encoded by NFR genes, that are useful for providing non-nodulating plants with Nod-factor binding properties and triggering the endosymbiotic signalling pathway leading to nodulation. Furthermore the invention is useful for breeding for improved nodulation in nodulating legumes.

Abstract: The present invention provides a Nod-factor binding element, comprising one or more NFR polypeptides encoded by NFR genes, that are useful for providing non-nodulating plants with Nod-factor binding properties and triggering the endosymbiotic signalling pathway leading to nodulation. Furthermore the invention is useful for breeding for improved nodulation in nodulating legumes.