Most clover rhizobial inoculants form effective nitrogen-fixing symbioses with either annual or perennial species (and very few with both). This constraint provides a considerable barrier to agricultural productivity since background populations of R. trifolii may nodulate with an incompatible host but ineffectively fix nitrogen (Yates et al 2008)

Bräu, L.

Goodwin, L.

Howieson, J.

O'Hara, G.W.

Reeve, W.

Tiwari, R.

Yates, R.J.

English

Research Repository

56 I> PA - 1 - 008 N2 FIXATION IN 25 COWPEA GENOTYPES MEASURED AT WA, MANGA (GHANA) AND TAUNG (SOUTH AFRICA) USING 15N NATURAL ABUNDANCE: GENOTYPE X ENVIRONMENT INTERACTION Alohon,u, K. Belane' 8: Felix D. Dakora" lDepartment of Crop Science, 2Department of Chemistry, Tshwane University of Technology, Pretoria, Private Bag X680, 0001; phonses08@gmail.com Field experiments were conducted at Wa and Manga in Ghana, and at Taung in South Africa in 2005, using a randomized complete block design with four replicates to assess the effects of genotype x environment (G x E) interaction on plant growth and symbiotic N2 fixation as location-specific differences have been indicated elsewhere (Belane and Dakora, 2009). Plants were sampled at 46 DAP (early pod-filling) and assessed for G x E interactions on dry matter yield, (j15N (%0), %Ndfa and N-fixed. The amount of dry matter produced differed markedly among the three locations, with greater DM yield being obtained at Manga. Dry matter yield ranged from 8.1 gat Taung to 66.1 g. genotype-1 at Manga except for the genotypes Apagbaala, Bensogla, Omondaw and Vuli-l which yielded greater dry matter at Wa. The i')1'N values at Taung were lower (-0.6 to 0.8 %0) than those at Wa (0.1 to 1.5%0) and Manga (1.3 to 4.8 %0). As a result, the %Ndfa values also differed (p,.;. 0.01) among locations with Manga showing a low 19 %, and Taung a high 84 %. The amount of N-fixed by cowpea genotypes also varied with locations. Generally, 16 cowpea genotypes revealed increased N~·fixation in all three environments. Dry matter was found to be greatly linked to amount of N-fixed. This work was supported by the McKnight Foundation and National Research Foundation of South Africa_ ~ PA - 1 - 009 -_ .. __ .. __ ... __ .. - .- .. __ ... _- ---TRACE ELEMENT DENSITY IN EDIBLE GRAIN AND LEAVES OF TWENTY ONE NODULATED COWPEA GENOTYPES FROM WA AND MANGA (IN GHANA) AND TAUNG (IN SOUTH AFRICA), MEASURED USING ICP-MASS SPECTROMETRY Alphon,u, K. Belane' 8: Felix D Dakora" 1Department of Crop Science, Department of ChemistryZ, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa; phonses08@gmail.com Micronutrient defiCiency is widespread across the world and represents a major problem to human health, especially in developing countries. Because micronutrients are naturally deficient in many African soils, locatly grown cereal crops tend to exhibit high levels of trace element deficiency. Yet many of these trace elements, such as Fe, In, Cu, Mn, Band Se, are important not only for the biosynthesis of important enzymes involved in plant and animal metabolism, but also critical for growth and brain development in humans, especially children. In South Africa, overcoming trace element deficiency and meeting the dietary requirements of micronutrients is done by direct supplementation of staple foods such maize flour with these minerals. However, we believe that selecting new genotypes of food crops with greater trace element density is a better approach and a more sustainable alternative to exogenous supplementation. In this study, 21 cowpea genotypes were screened at Wa and Manga in Ghana, and at Taung in South Africa, for their trace element densities in edible grain and leaves. The field experiment was conducted in 2005 using a randomized complete block design with four replications. At early flowering, young edible leaves were harvested from each replicate plot, oven-dried at 40°C, and ground for analysis of trace elements using inductively coupled plasma mass spectrometry (ICP-MS). At physiological maturity, cowpea grain was also harvested and similarly processed for the determination of trace element density. The data showed significant differences in trace element density among the genotypes a~ the three locations. Edible cowpea leaves showed markedly higher micronutrient densities relative to cowpea grain. There was also a significant genotype x environment (G x E) interaction. For example, Fe accumulation in cowpea leaves was 324.2 J.!g.g-1 at Wa, 321.6IJg.g-1 at Manga, and 551.9IJg.g-1 at Taung relative to 75.8, 59.8 and 59.0 IJg.g-1 Fe in the grain. The accumulation of Cu, In, Mn and B in leaves and grain showed a similar pattern as found for Fe. This work was supported by the McKnight Foundation and National Research Foundation of South Africa. I> PA - 1 - 010 -_. ---_. __ . __ . __ .. _-_ .. _- ._-MINING THE SEQUENCE DATA OF RHIZOBIUM LEGUMINOSARUM BV TRIFOLII WSM1325 AND WSM2304. Lambert Brau1, Lynn Goodwin2, Graham O'Hara1, Ravi TiwarP, John Howiesonl, Ron Yates3 & Wayne Reeve1 lCentre for Rhizobium Studies, Murdoch UniverSity, Murdoch, 6150, Western Australia.2 DOE Joint Genome Institute, California, USA. 3 Department of Agriculture Western Australia, Baron Hay Court, South Perth, 6151, Western Australia. Most dover rhizobial inoculants form effective nitrogen-fixing symbioses with either annual or perennial species (and very few with both). This constraint provides a considerable barrier to agricultural productivity since background populations of R. (. trifoUi may nodulate with an incompatible host but ineffectively fix nitrogen (Yates et al 2008). Knowledge at the genetic level is essential to develop an understanding of this incompatibility and progress in this pursuit will be greatty enhanced by complete genome sequence information. Thus, the genomes of two R. t. trifolii strains were sequenced by the US Joint Genome Institute Community Sequencing Program; the Mediterranean Trifolium spp. isolate WSM1325 and the South American Trifolium polymorphum isolate WSM2304. Strain WSM1325 is compatible with Mediterranean perennial dovers (ie with American or African perennial clovers whilst the reverse is true for strain WSMZ304. To sequence the genomes, a shotgun assembly approach was adopted to assemble a draft genome of each organism. Three libraries were constructed for each strain including one library for each strain in the functional genomics vector pTH15ZZ (Cowie et at, 2006). Assembly of the sequence data is in the draft stage and reveals that the genome of WSMZ304 is 6.8 Mb in size with a chromosome of 4.53 Mb and 4 plasmids of 1166, 501, 308 and 258 Kb. The genome has a G+C content of 61.1% and encodes 6590 candidate protein-encoding genes. In comparison, the WSM1325 genome is 7.8 Mb in size (529 contigs of 20 reads or greater), has a G+C content of 60.7% and encodes 7528 candidate protein-encoding genes. We will discuss comparative studies performed on the genome sequences of these two strains. Yates RJ, Howieson JG, Reeve WG, Briiu L, Speijers J, Nandasena K, Real D, Sezmis E 8: O'Hara GW (200S). Host-strain-mediated selection for an effective nitrogen· fixing symbiosis between Trifolium spp. and Rhizobium leguminosarum biovar trifolii. Soil Bioi Biochem 40: S22-B33. Cowie A, Cheng J, Sibley CD, Fang Y, Zaheer R, Patten Cl, Morton RM, Golding GB 8: Finan TM (2006). An Integrated Approach to Functional Genomics: Construction of a Novel Reporter Gene Fusion Library for Sinorhizobium meli/oti. Applied Environ Microbial 72:7156-7167. ~ PA - 1 - 011 ............ -.-----PROTEOMIC AND METABOLOMIC ANALYSIS OF SOYBEAN ROOT HAIRS COLONIZED BY BRADYRH/ZOBIUM JAPON/CUM Laurent Brechenmacher1, Zhen Tian LeF, Kim Hixson3, Marc Libault', Seth Findley', Roy Lowery', Brian Mooney", Ljiljana Pasa Tolic3, Lloyd W. Sumner2 and Gary Stacey',5' lNational Center for Soybean Biotechnology, Division of Plant Sciences, University of Missouri, Columbia, MO 65211, gstacey@missouri.edu 2Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, lwsumner@noble.org 3MassSpectrometryFacility, Environmental Molecular Sciences Laboratory, Richland, WA 99352, Ijiljana.pasatolic@pnl.gov 4 CharlesWGehrke Proteomic Center, University of Missouri, Columbia, MO 65211, mooneyb@missouri.edu 5 Division of Biochemistry and Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, MO 65211 Root hairs are single tubular cells formed from the differentiation of epidermal cells, called trichobtasts, on primary and secondary roots. They are involved in water and nutrient uptake, anchorage of the plant into the soil and represent the preferred infection site on leguminous roots by rhizobia. The interaction between soybean (Glycine max) and the bacterium Bradyrhizobium japonicum leads to the establishment of a nitrogen fixing symbiosis. The bacteria induce the formation of a specific new organ in the plant, the root nodule, in which they reduce atmospheric nitrogen to ammonia, which provides the plant host a consistent nitrogen source. Soybean was selected for this study due to its agronomic importance and its root size, which permits isolation of root hairs in sufficient amount for proteomic studies. In order to investigate the cellular changes that occur in the root hair upon rhizobial infection, we profiled both the root hair proteome and metabolome during the first 48 hours after B. japonicum inoculation. Proteins were extracted from root hairs 0,12 h, 18 h, 24 h, 36 hand 48 h after inoculation and compared to mock inoculated roots. Differential In Gel Electrophoresis (DlGE) was performed and identified 178 spots significantly regulated after B. japonicum inoculation (p<O.05). As a complementary approach, the proteome and phosphoproteome of B. japonicum-infected root hairs are also being analyzed using a non-gel based approach (LC MS/MS). The metabolome was also analyzed over the same time course. Primary metabolites from polar and lipophilic fractions were analyzed by GC-MS. Secondary metabolites were analyzed by UPLC- QtofMS. A total of 1688 metabolites were identified in root hairs by combining both approaches. Statistical analysis identified 121 compounds significantly regulated in root hairs colonized by B. japonicum (p<O.01). These included trehalose, maltose, lactic acid, apigenin, or afrormosin. The proteomic and metabolomic data, including transcriptomic data also available, are being integrated to provide a systems level view of the root hair response to B. japonicum infection. This work was supported by the National Sdence Foundation, Plant Genome Program (DBI·Q4Z16Z0) and the United Soybean Board. ~ PA - 1 - 012 PHYLOGENETIC DIVERSITY OF RHIZOBIAL STRAINS NODULATING CYTISUS TR/FLORUS Rajaa Chahboune', A. J, Sanchez·Raya2, E. J. Bedmar2 & Said Barrijal' 1Department of Biology, Faculty of Sciences and Techniques, University Abdelmalek Essaadi, Tangier, Morocco, and 2Department of Soil Microbiology and Symbiotic Systems, Estacion Experimental del Zaidin, CSIC, Granada, Spain .. The genetic diversity of 76 endophytic bacterial strains isolated from root nodules of Cytisus triflorus grown in the Aoudal and Fifi regions of the Moroquian Rif was analysed by Repetititve Extragenic Palindromic 57 

Mining the sequence data of Rhizobium Leguminosarum BV Trifolii WSM1325 and WM2304

https://researchrepository.murdoch.edu.au/id/eprint/3455/1/mining%20the%20sequence.pdf

Mining the sequence data of Rhizobium Leguminosarum BV Trifolii WSM1325 and WM2304

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