Identification of candidate genome regions controlling disease resistance in Arachis.

Background: Worldwide, diseases are important reducers of peanut (Arachis hypogaea) yield. Sources of resistance against many diseases are available in cultivated peanut genotypes, although often not in farmer preferred varieties. Wild species generally harbor greater levels of resistance and even apparent immunity, although the linkage of agronomically un-adapted wild alleles with wild disease resistance genes is inevitable.

A cytosolic invertase is required for normal growth and cell development in the model legume, Lotus japonicus.

Neutral/alkaline invertases are a subgroup, confined to plants and cyanobacteria, of a diverse family of enzymes. A family of seven closely-related genes, LjINV1-LjINV7, is described here and their expression in the model legume, Lotus japonicus, is examined. LjINV1 previously identified as encoding a nodule-enhanced isoform is the predominant isoform present in all parts of the plant.

Genetics of symbiosis in Lotus japonicus: recombinant inbred lines, comparative genetic maps, and map position of 35 symbiotic loci.

Development of molecular tools for the analysis of the plant genetic contribution to rhizobial and mycorrhizal symbiosis has provided major advances in our understanding of plant-microbe interactions, and several key symbiotic genes have been identified and characterized. In order to increase the efficiency of genetic analysis in the model legume Lotus japonicus, we present here a selection of improved genetic tools. The two genetic linkage maps previously developed from an interspecific cross between L.

Plastid proteins crucial for symbiotic fungal and bacterial entry into plant roots.

The roots of most higher plants form arbuscular mycorrhiza, an ancient, phosphate-acquiring symbiosis with fungi, whereas only four related plant orders are able to engage in the evolutionary younger nitrogen-fixing root-nodule symbiosis with bacteria. Plant symbioses with bacteria and fungi require a set of common signal transduction components that redirect root cell development. Here we present two highly homologous genes from Lotus japonicus, CASTOR and POLLUX, that are indispensable for microbial admission into plant cells and act upstream of intracellular calcium spiking, one of the earliest plant responses to symbiotic stimulation.