Arbuscular mycorrhizas are beneficial under both deficient and toxic soil zinc conditions
Background and aims
Arbuscular mycorrhizas (AM) play different roles in plant Zn nutrition depending on whether the soil is Zn-deficient (AM enhancement of plant Zn uptake) or Zn-toxic (AM protection of plant from excessive Zn uptake). In addition, soil P concentration modifies the response of AM to soil Zn conditions. We undertook a glasshouse experiment to study the interactive effects of P and Zn on AM colonisation, plant growth and nutrition, focusing on the two extremes of soil Zn concentration—deficient and toxic.
We used a mycorrhiza-defective tomato (Solanum lycopersicum) genotype (rmc) and compared it to its wild-type counterpart (76R). Plants were grown in pots amended with five soil P addition treatments, and two soil Zn addition treatments.
The mycorrhizal genotype generally thrived better than the non-mycorrhizal genotype, in terms of biomass and tissue P and Zn concentrations. This was especially true under low soil Zn and P conditions, however there was evidence of the ‘protective effect’ of mycorrhizas when soil was Zn-contaminated. Above- and below-ground allocation of biomass, P and Zn were significantly affected by AM colonisation, and toxic soil Zn conditions.
The relationship between soil Zn and soil P was highly interactive, and heavily influenced AM colonisation, plant growth, and plant nutrition.
KeywordsArbuscular mycorrhizas (AM) Zinc Phosphorus Mycorrhiza defective tomato mutant (rmc) Solanum lycopersicum (Tomato)
The authors wish to thank Dr Michael Rose and other members of the ‘Cav-Lab’ for valuable discussions. We also gratefully acknowledge Dr Susan Barker and Prof. Sally Smith for continued access to the rmc and 76R genotypes of tomato. This research was in part funded by the Monash University, School of Biological Sciences. TRC also wishes to acknowledge the Australian Research Council and the Monash Research Accelerator program for financial support.
- Burns AE, Gleadow RM, Zacarias AM, Cuambe CE, Miller RE, Cavagnaro TR (2012) Variations in the chemical composition of cassava (Manihot esculenta Crantz) leaves and roots as affected by genotypic and environmental variation. J Agric Food Chem 60(19):4946–4956. doi: 10.1021/jf2047288 PubMedCrossRefGoogle Scholar
- Chen BD, Shen H, Li XL, Feng G, Christie P (2004) Effects of EDTA application and arbuscular mycorrhizal colonization on growth and zinc uptake by maize (Zea mays L.) in soil experimentally contaminated with zinc. Plant Soil 261(1–2):219–229. doi: 10.1023/B:PLSO.0000035538.09222.ff CrossRefGoogle Scholar
- Facelli E, Smith SE, Facelli JM, Christophersen HM, Smith FA (2010) Underground friends or enemies: model plants help to unravel direct and indirect effects of arbuscular mycorrhizal fungi on plant competition. New Phytol 185(4):1050–1061. doi: 10.1111/j.1469-8137.2009.03162.x PubMedCrossRefGoogle Scholar
- Gonzalez-Guerrero M, Azcon-Aguilar C, Mooney M, Valderas A, MacDiarmid CW, Eide DJ, Ferrol N (2005) Characterization of a Glomus intraradices gene encoding a putative Zn transporter of the cation diffusion facilitator family. Fungal Genet Biol 42(2):130–140. doi: 10.1016/j.fgb.2004.10.007 PubMedCrossRefGoogle Scholar
- Gonzalez-Guerrero M, Melville LH, Ferrol N, Lott JNA, Azcon-Aguilar C, Peterson RL (2008) Ultrastructural localization of heavy metals in the extraradical mycelium and spores of the arbuscular mycorrhizal fungus Glomus intraradices. Can J Microbiol 54(2):103–110. doi: 10.1139/w07-119 PubMedCrossRefGoogle Scholar
- Impa SM, Johnson-Beebout S (2012) Mitigating zinc deficiency and achieving high grain Zn in rice through integration of soil chemistry and plant physiology research. Plant and Soil:1-39. doi:10.1007/s11104-012-1315-3Google Scholar
- Kizilgoz I, Sakin E (2010) The effects of increased phosphorus application on shoot dry matter, shoot P and Zn concentrations in wheat (Triticum durum L.) and maize (Zea mays L.) grown in a calcareous soil. Afr J Biotechnol 9(36):5893–5896Google Scholar
- Larue JH, McClellan WD, Peacock WL (1975) Mycorrhizal fungi and peach nursery nutrition. Calif Agric 29(5):7Google Scholar
- Leyval C, Berthelin J, Schontz D, Weissenhorn I, Morel JL (1991) Influence of endomycorrhizas on maize uptake of Pb, Cu, Zn and Cd applied as mineral salts or sewage sludge. In: Farmer JG (ed) Heavy metals in the environment. CEP Consultants Ltd., EdinburghGoogle Scholar
- Marschner H, Dell B (1994) Nutrient uptake in mycorrhizal symbiosis. Plant Soil 159(1):89–102Google Scholar
- Nord EA, Shea K, Lynch JP (2011) Optimizing reproductive phenology in a two-resource world: a dynamic allocation model of plant growth predicts later reproduction in phosphorus-limited plants. Ann Bot. doi: 10.1093/aob/mcr143
- Poulsen KH, Nagy R, Gao LL, Smith SE, Bucher M, Smith FA, Jakobsen I (2005) Physiological and molecular evidence for Pi uptake via the symbiotic pathway in a reduced mycorrhizal colonization mutant in tomato associated with a compatible fungus. New Phytol 168(2):445–453. doi: 10.1111/j.1469-8137.2005.01523.x PubMedCrossRefGoogle Scholar
- Smith SE, Read DJ (2008) Mycorrhizal symbiosis, 3rd edn. Academic, New YorkGoogle Scholar
- Tinker PB, Nye PH (2000) Solute movement in the rhizosphere. Oxford University Press, OxfordGoogle Scholar
- Zar JH (2007) Biostatistical Analysis (5th Edition). Prentice-Hall, Inc.,Google Scholar