Complete genome sequence of Mesorhizobium australicum type strain (WSM2073T)

Mesorhizobium australicum strain WSM2073^T was isolated from root nodules on the pasture legume Biserrula pelecinus growing in Australia in 2000. This aerobic, motile, gram negative, non-spore-forming rod is poorly effective in N₂ fixation on B. pelecinus and has gained the ability to nodulate B. pelecinus following in situ lateral transfer of a symbiosis island from the original inoculant strain for this legume, Mesorhizobium ciceri bv. biserrulae WSM1271. We describe that the genome size of M. australicum strain WSM2073^T is 6,200,534 bp encoding 6,013 protein-coding genes and 67 RNA-only encoding genes. This genome does not contain any plasmids but has a 455.7 kb genomic island from Mesorhizobium ciceri bv. biserrulae WSM1271 that has been integrated into a phenylalanine-tRNA gene.     

Genome sequence of Ensifer medicae strain WSM1369; an effective microsymbiont of the annual legume Medicago sphaerocarpos

Ensifer medicae WSM1369 is an aerobic, motile, Gram-negative, non-spore-forming rod that can exist as a soil saprophyte or as a legume microsymbiont of Medicago. WSM1369 was isolated in 1993 from a nodule recovered from the roots of Medicago sphaerocarpos growing at San Pietro di Rudas, near Aggius in Sardinia (Italy). WSM1369 is an effective microsymbiont of the annual forage legumes M. polymorpha and M. sphaerocarpos. Here we describe the features of E. medicae WSM1369, together with genome sequence information and its annotation. The 6,402,557 bp standard draft genome is arranged into 307 scaffolds of 307 contigs containing 6,656 protein-coding genes and 79 RNA-only encoding genes. This rhizobial genome is one of 100 sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) project.     

Genome sequence of the lupin-nodulating Bradyrhizobium sp. strain WSM1417

Bradyrhizobium sp. strain WSM1417 is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from an effective nitrogen (N₂) fixing root nodule of Lupinus sp. collected in Papudo, Chile, in 1995. However, this microsymbiont is a poorly effective N₂ fixer with the legume host Lupinus angustifolius L.; a lupin species of considerable economic importance in both Chile and Australia. The symbiosis formed with L. angustifolius produces less than half of the dry matter achieved by the symbioses with commercial inoculant strains such as Bradyrhizobium sp. strain WSM471. Therefore, WSM1417 is an important candidate strain with which to investigate the genetics of effective N₂ fixation in the lupin-bradyrhizobia symbioses. Here we describe the features of Bradyrhizobium sp. strain WSM1417, together with genome sequence information and annotation. The 8,048,963 bp high-quality-draft genome is arranged in a single scaffold of 2 contigs, contains 7,695 protein-coding genes and 77 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program.     

Genome sequence of the Trifolium rueppellianum -nodulating Rhizobium leguminosarum bv. trifolii strain WSM2012.

Rhizobium leguminosarum bv. trifolii WSM2012 (syn. MAR1468) is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from an ineffective root nodule recovered from the roots of the annual clover Trifolium rueppellianum Fresen growing in Ethiopia. WSM2012 has a narrow, specialized host range for N₂-fixation. Here we describe the features of R. leguminosarum bv. trifolii strain WSM2012, together with genome sequence information and annotation. The 7,180,565 bp high-quality-draft genome is arranged into 6 scaffolds of 68 contigs, contains 7,080 protein-coding genes and 86 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program.     

Complete genome sequence of Mesorhizobium ciceri bv. biserrulae type strain (WSM1271T)

Mesorhizobium ciceri bv. biserrulae strain WSM1271^T was isolated from root nodules of the pasture legume Biserrula pelecinus growing in the Mediterranean basin. Previous studies have shown this aerobic, motile, Gram negative, non-spore-forming rod preferably nodulates B. pelecinus – a legume with many beneficial agronomic attributes for sustainable agriculture in Australia. We describe the genome of Mesorhizobium ciceri bv. biserrulae strain WSM1271^T consisting of a 6,264,489 bp chromosome and a 425,539 bp plasmid that together encode 6,470 protein-coding genes and 61 RNA-only encoding genes.     

Root nodule bacteria isolated from South African <Emphasis Type="Italic">Lotononis bainesii,L. listii</Emphasis> and <Emphasis Type="Italic">L. solitudinis</Emphasis> are species of <Emphasis Type="Italic">Methylobacterium</Emphasis> that are unable to utilize methanol

The South African legumes Lotononis bainesii, L. listii and L. solitudinis are specifically nodulated by highly effective, pink-pigmented bacteria that are most closely related to Methylobacterium nodulans on the basis of 16S rRNA gene homology. Methylobacterium spp. are characterized by their ability to utilize methanol and other C₁ compounds, but 11 Lotononis isolates neither grew on methanol as a sole carbon source nor were able to metabolize it. No product was obtained for PCR amplification of mxaF, the gene encoding the large subunit of methanol dehydrogenase. Searches for methylotrophy genes in the sequenced genome of Methylobacterium sp. 4-46, isolated from L. bainesii, indicate that the inability to utilize methanol may be due to the absence of the mxa operon. While methylotrophy appears to contribute to the effectiveness of the Crotalaria/M. nodulans symbiosis, our results indicate that the ability to utilize methanol is not a factor in the Lotononis/Methylobacterium symbiosis.     

A prospective study of cognitive health in the elderly (Oregon Brain Aging Study): effects of family history and apolipoprotein E genotype.

The oldest old are the fastest-growing segment of our population and have the highest prevalence of dementia. Little is known about the genetics of cognitive health in the very old. The aim of this study was to determine whether the genetic risk factors for Alzheimer disease (AD)--namely, apolipoprotein E (APOE) epsilon4 allele and a family history of dementia-continue to be important factors in the cognitive health of the very old. Case-control studies suggest that the effect of genetic factors diminishes at age >75 years. The present prospective study provided evidence to the contrary. We studied 114 Caucasian subjects who were physically healthy and cognitively intact at age 75 years and who were followed, for an average of 4 years, with neurological, psychometric, and neuroimaging examinations. Excellent health at entry did not protect against cognitive decline. Incidence of cognitive decline rose sharply with age. epsilon4 and a family history of dementia (independent of epsilon4) were associated with an earlier age at onset of dementia. Subjects who had epsilon4 or a family history of dementia had a ninefold-higher age-specific risk for dementia than did those who had neither epsilon4 nor a family history of dementia. These observations suggest that the rate of cognitive decline increases with age and that APOE and other familial/genetic factors influence the onset age throughout life.     

Rethinking soil water repellency and its management

Plant Ecology - Soil water repellency (SWR) is a widespread challenge to plant establishment and growth. Despite considerable research, it remains a recalcitrant problem for which few alleviation...