Overexpression of an Arabidopsis magnesium transport gene, AtMGT1, in Nicotiana benthamiana confers Al tolerance

J Exp Bot. 2006;57(15):4235-43. doi: 10.1093/jxb/erl201. Epub 2006 Nov 13.

Abstract

Aluminium (Al) toxicity is the most important limiting factor for crop production in acid soil environments worldwide. In some plant species, application of magnesium (Mg(2+)) can alleviate Al toxicity. However, it remains unknown whether overexpression of magnesium transport proteins can improve Al tolerance. Here, the role of AtMGT1, a member of the Arabidopsis magnesium transport family involved in Mg(2+) transport, played in Al tolerance in higher plants was investigated. Expression of 35S::AtMGT1 led to various phenotypic alterations in Nicotiana benthamiana plants. Transgenic plants harbouring 35S::AtMGT1 exhibited tolerance to Mg(2+) deficiency. Element assay showed that the contents of Mg, Mn, and Fe in 35S::AtMGT1 plants increased compared with wild-type plants. Root growth experiment revealed that 100 microM AlCl(3) caused a reduction in root elongation by 47% in transgenic lines, whereas root growth in wild-type plants was inhibited completely. Upon Al treatment, representative transgenic lines also showed a much lower callose deposition, an indicator of increased Al tolerance, than wild-type plants. Taken together, the results have demonstrated that overexpression of ATMGT1 encoding a magnesium transport protein can improve tolerance to Al in higher plants.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aluminum / metabolism
  • Aluminum / toxicity*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Arabidopsis Proteins / physiology
  • Cation Transport Proteins / genetics*
  • Cation Transport Proteins / metabolism
  • Cation Transport Proteins / physiology
  • Caulimovirus / genetics
  • Glucans / metabolism
  • Iron / metabolism
  • Magnesium / metabolism
  • Manganese / metabolism
  • Nicotiana / drug effects
  • Nicotiana / genetics*
  • Nicotiana / growth & development
  • Phenotype
  • Plant Roots / drug effects
  • Plant Roots / growth & development
  • Plants, Genetically Modified / drug effects
  • Plants, Genetically Modified / growth & development
  • Plants, Genetically Modified / metabolism
  • Promoter Regions, Genetic

Substances

  • Arabidopsis Proteins
  • Cation Transport Proteins
  • Glucans
  • MGT1 protein, Arabidopsis
  • Manganese
  • callose
  • Aluminum
  • Iron
  • Magnesium