Genetic variation for root architecture, nutrient uptake and mycorrhizal colonisation in Medicago truncatula accessions
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Sustainable agriculture strives for healthy, high yielding plants with minimal agronomic inputs. Genetic solutions to increase nutrient uptake are desirable because they provide ongoing improvements. To achieve this it is necessary to identify genes involved in uptake and translocation of nutrients. We selected Medicago truncatula L. as a model because of its: i) close genetic relationship to food legumes, ii) use as a pasture legume in southern Australia and iii) availability of mapping populations generated from genetically diverse accessions. We discovered statistically significant differences between eight accessions for: root architecture in growth pouches, % root colonisation with the arbuscular mycorrhizal (AM) fungus Glomus intraradices, and plant tissue concentration of most macro- and micronutrients. Mycorrhizal colonisation had a significant effect on P concentration in roots but not shoots, Mg concentration in both roots and shoots, and the concentration of various micronutrients in shoots including Fe, Ca, but not Zn. Comparison of micronutrient uptake between root and shoot tissues showed that some M. truncatula accessions were more efficient at mobilisation of nutrients from roots to shoots. We are now in a position to use existing mapping populations of M. truncatula to identify quantitative trait loci important for human health and sustainable agriculture.
KeywordsRoot architecture Micronutrient Arbuscular mycorrhizal fungi Legume Low-input cropping Zinc
We gratefully thank Simon Ellwood and Richard Oliver for providing information on the availability of M. truncatula mapping populations. Accessions DZA045 and F83005 were kindly provided by David Bird. Expert technical assistance was provided by Eric Craft (nutrient analysis) and Jean-Patrick Toussaint (AM colonisation). Kathy Crowley provided access to and assistance with WinRHIZO. We thank Evelina Facelli for statistical advice and gratefully acknowledge Sally Smith, Andrew Smith and James Stangoulis for valuable discussions and critical comments on the manuscript. Financial assistance was provided by the AW Howard Memorial Trust Inc. for a travel grant (to CJS) and the U.S. National Science Foundation (DBI-0421676 to M.J.H).
- Arnon DI, Hoagland DR (1940) Crop production in artificial culture solutions and in soils with special reference to factors influencing yields and absorption of inorganic nutrients. Soil Science 50:463–483Google Scholar
- Baxter I, Muthukumar B, Park HC, Buchner P, Lahner B, Danku J, Zhao K, Lee J, Hawkesford MJ, Guerinot ML, Salt DE (2008) Variation in molybdenum content across broadly distributed populations of Arabidopsis thaliana is controlled by a mitochondrial molybdenum transporter (MOT1). PLoS Genet 4:e1000004CrossRefPubMedGoogle Scholar
- Berta G, Fusconi A, Hooker JE (2002) Arbuscular mycorrhizal modifications to plant root systems: scale, mechanisms and consequences. In: Gianninazzi S, Schüepp H, Barea JM, Haselwandter K (eds) Mycorrhizal technology in agriculture. Birkhäuser Verlag, Basel, pp 71–85Google Scholar
- Kamphuis LG, Lichtenzveig J, Oliver RP, Ellwood SR (2008) Two alternative recessive quantitative trait loci influence resistance to spring black stem and leaf spot in Medicago truncatula. BMC Plant Biol 8Google Scholar
- Nichols PGH, Loi A, Nutt BJ, Evans PM, Craig AD, Pengelly BC, Dear BS, Lloyd DL, Revell CK, Nair RM, Ewing MA, Howieson JG, Auricht GA, Howie JH, Sandral GA, Carr SJ, de Koning CT, Hackney BF, Crocker GJ, Snowball R, Hughes EJ, Hall EJ, Foster KJ, Skinner PW, Barbetti MJ, You MP (2007) New annual and short-lived perennial pasture legumes for Australian agriculture—15 years of revolution. Field Crops Res 104:10–23CrossRefGoogle Scholar
- Rengel Z (1995) Carbonic anhydrase activity in leaves of wheat genotypes differing in Zn efficiency. J Plant Physiol 147:251–256Google Scholar
- Ronfort J, Bataillon T, Santoni S, Delalande M, David J, Prosperi J-M (2006) Microsatellite diversity and broad scale geographic structure in a model legume: building a set of nested core collection for studying naturally occurring variation in Medicago truncatula. BMC Plant Biol 6:28CrossRefPubMedGoogle Scholar
- Smith S, Read D (2008) Mycorrhizal symbiosis, 3rd edn. Academic, New YorkGoogle Scholar
- Sun Y, Li XL, Feng G (2008) Effect of arbuscular mycorrhizal colonization on ecological functional traits of ephemerals in the Gurbantonggut desert. Symbiosis 46:121–127Google Scholar
- Zar JH (1984) Biostatistical analysis, 2nd edn. Prentice-Hall, Englewood CliffsGoogle Scholar