Nodulation in legumes requires the recognition of rhizobially made Nod factors. Genetic studies have revealed that the perception of Nod factors involves LysM domain receptor-like kinases, while biochemical approaches have identified LECTIN NUCLEOTIDE PHOSPHOHYDROLASE (LNP) as a Nod factor-binding protein. Here, we show that antisense inhibition of LNP blocks nodulation in Lotus japonicus. This...

We isolated a recessive symbiotic mutant of Lotus japonicus that defines a genetic locus, LOT1 (for low nodulation and trichome distortion). The nodule number per plant of the mutant was about one-fifth of that of the wild type. The lot1 mutant showed a moderate dwarf phenotype and distorted trichomes, but its root hairs showed no apparent differences to those of the wild type. Infection thread...

abstract arsenic (as) contamination of soils is a global problem. legumes are often used in remediation of contaminated sites because of their capacity to fix nitrogen. in the present study, the effects of inoculation of bean (by rhizobium leguminosarum bv. phaseoli) on plant uptake and tolerance to arsenic were investigated. an experiment with a factorial arrangement, two levels of inoculation...

The effects of 2 mM silicon (Si) and 10 mM KNO₃ (N)-prime signals for plant resistance to pathogens-were analyzed in healthy and Cowpea chlorotic mottle virus (CCMV) or Cowpea mild mottle virus (CMMV)-infected Bradyrhizobium-nodulated cowpea, yardlong bean and mung bean plants. In healthy plants of the three Vigna taxa, nodulation and growth were promoted in the order of Si + N > N > Si > contr...

The common nodulation locus and closely linked nodulation genes of Bradyrhizobium (Arachis) sp. strain NC92 have been isolated on an 11.0-kb EcoRI restriction fragment. The nucleotide sequence of a 7.0-kb EcoRV-EcoRI subclone was determined and found to contain open reading frames (ORFs) homologous to the nodA, nodB, nodD1, nodD2, and nolA genes of Bradyrhizobium japonicum and Bradyrhizobium el...

Are giant clams endangered? Giant clam species are extinct or in danger of extinction in many parts of their distributions, despite being listed in the IUCN Red List of Threatened Species and Appendix II of the Convention on International Trade in Endangered Species (CITES). The shells of the smaller species are often found in shell and tourist shops around the world. The large species have bee...

Legumes control their nodule numbers through the autoregulation of nodulation (AON). Rhizobia infection stimulates production root-derived CLE peptide hormones that are translocated to shoot where they regulate a new signal. We used soybean demonstrate this shoot-derived signal is miR2111, which transported via phloem root it targets transcripts Too Much Love (TML), negative regulator nodulatio...

RNA interference-mediated silencing of the key flavonoid and isoflavone biosynthesis enzyme, respectively, by two different research groups has provided direct genetic evidence for the essential roles that these compounds play in nodulation. Anton Wasson et al. have shown that flavonoids are essential for localized auxin transport inhibition during nodulation in the indeterminate legume Medicag...

Nodulations of Glycine max L. seedlings by parental Rhizobium japonicum (USDA strain 26) and a tryptophan catabolic mutant (tan 4b, NRRL strain B-14075) were evaluated for effectiveness. Seedlings grown in plastic pouches were compared based on increases in root weight (wt.), nodule volume (vol.) and acetylene-reducing (AR) activity. The tan 4b mutant, which can produce extracellular indol-3yl-...

Using a plate induction assay, we demonstrate that alfalfa exudes inducer of Rhizobium meliloti nodulation genes. The inducer is exuded from the infectible zone of the root, accumulates to at least 1 micromolar, and is not affected by 10 millimolar nitrate. No zones of inhibition are observed. A nodulation minus mutant line of alfalfa, MN-1008, exudes normal levels of inducer. R. meliloti grown...