Inoculum droplets of approximately 10 nanoliter volume and containing about 10 Rhizobium meliloti cells were placed onto the root surface of alfalfa seedlings in plastic growth pouches at either the root tip, the position of the smallest emergent root hairs, or at a site midway between these points. The droplets were initially confined to an area of about 0.2 square millimeter at the point of a...

The large size and complexity of the garden pea (Pisum sativum L.) genome hamper its sequencing and the discovery of pea gene resources. Although transcriptome sequencing provides extensive information about expressed genes, some tissue-specific transcripts can only be identified from particular organs under appropriate conditions. In this study, we performed RNA sequencing of polyadenylated tr...

Frankia spp. strains typically induce N2-fixing root nodules on actinorhizal plants. The majority of host plant taxa associated with the uncultured Group 1 Frankia strains, i.e., Ceanothus of the Rhamnaceae, Datisca glomerata (Datiscaceae), and all actinorhizal members of the Rosaceae except Dryas, are found in California. A study was conducted to determine the distribution of Frankia strains a...

Naturally occurring nitrogen-fixing symbionts from root nodules of caragana (Caragana arborescens) growing in central Saskatchewan were isolated following surface sterilization of caragana root nodules and squashing and spreading of the contents on yeast extract - mannitol medium. The symbiotic nature of the strains was confirmed following inoculation onto surface-sterilized C. arborescens seed...

Native strains of Bradyrhizobium japonicum were tested for their effectiveness on nodulation, crop yield and nitrogen fixation in soybean (Glycine max). B. japonicum strains were isolated from soybean root nodules collected from different agro-climatic regions of Far Western Nepal, viz. Dipayal (607 m asl), Dadeldhura (1097 m asl), Silgadhi (1209 m asl) and Bajura (1524 m asl). The strains were...

S (PH D THESIS) Involvement of auxin distribution in root nodule development of Lotus japonicus (Graduate School of Agriculture, Laboratory of Plant Gene Expression, RISH, Kyoto University) Kojiro TAKANASHI Legumes (Fabaceae) constitute the third largest plant family with around 700 genera and 20,000 species. Legume plants form root nodules through symbiosis with a soil microbe called rhizobia....

S (PH D THESIS) Involvement of auxin distribution in root nodule development of Lotus japonicus (Graduate School of Agriculture, Laboratory of Plant Gene Expression, RISH, Kyoto University) Kojiro TAKANASHI Legumes (Fabaceae) constitute the third largest plant family with around 700 genera and 20,000 species. Legume plants form root nodules through symbiosis with a soil microbe called rhizobia....

Nitrogen-fixing nodules induced by Frankia in the actinorhizal plant Discaria trinervis result from a primitive intercellular root invasion pathway that does not involve root hair deformation and infection threads. Here, we analyzed the role of auxin in this intercellular infection pathway at the molecular level and compared it with our previous work in the intracellular infected actinorhizal p...

The aim of this study was to evaluate the diversity of rhizobial isolates obtained from root nodules of pigeonpea plants grown at the eastern edge of the Brazilian Pantanal. The bacterial isolates were isolated from root nodules from field-growing pigeonpea grown in two rural settlements of the Aquidauana municipality. The bacterial isolates were characterized phenotypically by means of cultura...

The contribution of carbon and nitrogen reserves to regrowth following shoot removal has been studied in the past. However, important gaps remain in understanding the effect of shoot cutting on nodule performance and its relevance during regrowth. In this study, isotopic labelling was conducted at root and canopy levels with both (15) N2 and (13) C-depleted CO2 on exclusively nitrogen-fixing al...