Model of Al transport across the root.
Aluminium/silicon interactions in cereals
Aluminium/silicon interactions in cereals.
Aluminium toxicity is a serious problem for plants growing on acid soils, and the acidity can be caused naturally, as in many tropical soils. Silicon may be involved in aluminium (aluminum in the US!) tolerance mechanisms in plants and I found that silicon can ameliorate some of the toxic effects of aluminium in sorghum (see Aluminium/silicon interactions
In the mid-90's I was joined by David Evans in BMS. Kim Hammond worked with David and myself on aluminium/silicon interactions in barley for her undergraduate project. David was successful in getting her a Royal Society summer studentship, during which she completed her work, and you can see it in:
HAMMOND, K.E., EVANS, D.E. & HODSON, M.J. (1995) Aluminium/silicon interactions in barley (Hordeum vulgare L.) seedlings. Plant and Soil 173, 89-95.
Work by Kay Cocker (now Miller) on wheat (supervised jointly by David Evans) has shown that the amelioration depends on concentration, pH and cultivar. It now seems certain that this effect is not a quirk of solution chemistry, but has an in planta component. Amelioration may be partly due to precipitation of aluminium in the epidermal cell walls of the root. Papers on this topic include:
COCKER, K.M., HODSON, M.J., EVANS, D.E. & SANGSTER, A.G. (1997) The interaction between silicon and aluminium in Triticum aestivum L. (cv. Celtic). Israel Journal of Plant Sciences 45, 285-292.
COCKER, K.M., EVANS, D.E. & HODSON, M.J. (1998) The amelioration of aluminium toxicity by silicon in wheat (Triticum aestivum L.): malate exudation as evidence for an in planta mechanism. Planta 204, 318-323.
COCKER, K.M., EVANS, D.E. & HODSON, M.J. (1998) The amelioration of aluminium toxicity by silicon in higher plants: solution chemistry or an in planta mechanism? Physiologia Plantarum 104, 608-614.