Does the major aluminium-resistance gene in wheat, TaALMT1, also confer tolerance to alkaline soils?
A major limitation to plant growth in acid soils is the prevalence of toxic Al3+. Most genotypic variation for acid soil-tolerance in wheat is linked with the Al3+-activated efflux of malate anions from roots which is controlled by TaALMT1 on chromosome 4DL. Recent studies have also linked TaALMT1 with tolerance to high pH solutions and alkaline soils. This study tested the hypothesis that an Al3+-resistant allele of TaALMT1 also confers tolerance to alkaline conditions.
The near-isogenic wheat lines, ET8 (Al3+-resistant) and ES8 (Al3+-sensitive), have different alleles of the TaALMT1 gene and contrasting resistance to Al3+ toxicity. Growth of these lines was compared in acid and alkaline soils with contrasting mineralogy and in a range of high pH hydroponic solutions of varying composition.
No consistent differences in root or shoot growth were detected between the lines in the alkaline soils or in the high pH hydroponic treatments. Malate efflux was detected from ET8 in acidic solution with Al3+ but no substantial malate efflux was detected at pH 9.0 treatment with added Na2SO4.
The results are inconsistent with the hypothesis that the TaALMT1 gene confers an advantage to wheat on alkaline soils.
KeywordsWheat Malate TaALMT1 Aluminum Resistance Tolerance Alkaline Acidic Soil Boron
The authors are grateful to Glenn McDonald, Rhiannon Schilling, Ian Richter and Naomi Scholz for providing alkaline soils from South Australia. We thank Kumara Weligama for assistance in characterizing the soils. Carolina Silva’s research was supported by the São Paulo Research Foundation (Fapesp) in Brazil.
- Dolling P, Moody P, Noble I, Helyar K, Hughes B, Reuter D, Sparrow L (2001) Soil acidity and acidification in Australia. National Land and Water Resources Audit Project Report, CanberraGoogle Scholar
- Foy CD (1984) Physiological effects of hydrogen, aluminum, and manganese toxicities in acid soil. In: Adams F (ed) Soil acidity and liming. American Society of Agronomy, Crop Science Society, American Society of Soil Science, MadisonGoogle Scholar
- Helyar KR (1991) The management of acid soils. In: Wright RJ (ed) Plant-soil interactions at low pH. p 365-382. Kluwer Academic, DordrechtGoogle Scholar
- Kochian LV, Pineros MA, Liu J, Magalhaes JV (2015) Plant Adaptation to Acid Soils: The Molecular Basis for Crop Aluminum Resistance. Annu Rev Plant Biol 66:571–598. https://doi.org/10.1146/annurev-arplant-043014-114822 CrossRefPubMedGoogle Scholar
- Liu J, Xu M, Estavillo G, Delhaize E, White RM, Zhou M, Ryan PR (2017) OsALMT4 encodes a malate-permeable anion channel in rice (Oryza sativa L.) which is expressed widely and required for normal growth in low light. Plant Physiol (submitted)Google Scholar
- Magalhaes JV, Liu J, Guimaraes CT, Lana UGP, Alves VMC, Wang YH, Schaffert RE, Hoekenga OA, Pineros MA, Shaff JE, Klein PE, Carneiro NP, Coelho CM, Trick HN, Kochian LV (2007) A gene in the multidrug and toxic compound extrusion (MATE) family confers aluminum tolerance in sorghum. Nat Genet 39:1156–1161. https://doi.org/10.1038/ng2074 CrossRefPubMedGoogle Scholar
- Millar AL, Rathjen AJ, Cooper DS (2007) Genetic variation for subsoil toxicities in high pH soils. In: Buck HT, Nisi JE, Salomon N (eds) Wheat production in stressed environments. Springer, DordrechtGoogle Scholar
- Pereira JF, Zhou G, Delhaize E, Richardson T, Ryan PR (2010) Engineering greater aluminium resistance in wheat by over-expressing TaALMT1. J Exp Bot 106:205–214Google Scholar
- Raman H, Ryan PR, Raman R, Stodart BJ, Zhang K, Martin P, Wood R, Sasaki T, Yamamoto Y, Mackay M, Hebb DM, Delhaize E (2008) Analysis of TaALMT1 traces the transmission of aluminum resistance in cultivated common wheat (Triticum aestivum L.) Theor Appl Genet 116:343–354. https://doi.org/10.1007/s00122-007-0672-4 CrossRefPubMedGoogle Scholar
- Raman H, Zhang KR, Cakir M, Appels R, Garvin DF, Maron LG, Kochian LV, Moroni JS, Raman R, Imtiaz M, Drake-Brockman F, Waters I, Martin P, Sasaki T, Yamamoto Y, Matsumoto H, Hebb DM, Delhaize E, Ryan PR (2005) Molecular characterization and mapping of ALMT1, the aluminium-tolerance gene of bread wheat (Triticum aestivum L.) Genome 48:781–791CrossRefPubMedGoogle Scholar
- Ramesh SA, Tyerman SD, Xu B, Bose J, Kaur S, Conn V, Domingos P, Ullah S, Wege S, Shabala S, Feijo JA, Ryan PR, Gilliham M (2015) GABA signalling modulates plant growth by directly regulating the activity of plant-specific anion transporters. Nat Commun 6. doi: https://doi.org/10.1038/ncomms8879
- Sasaki T, Ryan PR, Delhaize E, Hebb DM, Ogihara Y, Kawaura K, Noda K, Kojima T, Toyoda A, Matsumoto H, Yamamoto Y (2006) Sequence upstream of the wheat (Triticum aestivum L.) ALMT1 gene and its relationship to aluminum resistance. Plant Cell Physiol 47:1343–1354. https://doi.org/10.1093/pcp/pcl002 CrossRefPubMedGoogle Scholar