Superior aluminium (Al) tolerance of Stylosanthes is achieved mainly by malate synthesis through an Al-enhanced malic enzyme, SgME1
Article first published online: 11 DEC 2013
© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust
Volume 202, Issue 1, pages 209–219, April 2014
How to Cite
Sun, L., Liang, C., Chen, Z., Liu, P., Tian, J., Liu, G. and Liao, H. (2014), Superior aluminium (Al) tolerance of Stylosanthes is achieved mainly by malate synthesis through an Al-enhanced malic enzyme, SgME1. New Phytologist, 202: 209–219. doi: 10.1111/nph.12629
- Issue published online: 25 FEB 2014
- Article first published online: 11 DEC 2013
- Manuscript Accepted: 6 NOV 2013
- Manuscript Received: 31 AUG 2013
- National Key Basic Research Special Funds of China. Grant Number: 2011CB100301
- National Natural Science Foundation of China. Grant Number: 31025022
- Earmarked Fund for China Agriculture Research System. Grant Number: CARS-35
- aluminium (Al) tolerance;
- malate exudation;
- malate synthesis;
- malic enzyme;
- Stylosanthes (stylo) is a dominant leguminous forage in the tropics. Previous studies suggest that stylo has great potential for aluminium (Al) tolerance, but little is known about the underlying mechanism.
- A novel malic enzyme, SgME1, was identified from the Al-tolerant genotype TPRC2001-1 after 72 h Al exposure by two-dimensional electrophoresis, and the encoding gene was cloned and characterized via heterologous expression in yeast, Arabidopsis thaliana and bean (Phaseolus vulgaris) hairy roots.
- Internal Al detoxification might be mainly responsible for the 72 h Al tolerance of TPRC2001-1, as indicated by 5.8-fold higher root malate concentrations and approximately two-fold higher Al concentrations in roots and root symplasts of TPRC2001-1 than those of the Al-sensitive genotype Fine-stem. An accompanying increase in malate secretion might also reduce a fraction of Al uptake in TPRC2001-1. Gene and protein expression of SgME1 was only enhanced in TPRC2001-1 after 72 h Al exposure. Overexpressing SgME1 enhanced malate synthesis and rescued yeast, A. thaliana and bean hairy roots from Al toxicity via increasing intracellular malate concentrations and/or accompanied malate exudation.
- These results provide strong evidence that superior Al tolerance of stylo is mainly conferred by Al-enhanced malate synthesis, functionally controlled by SgME1.