Aluminium cycling in the soil-plant-animal-human continuum.
A critical review of the literature on Al toxicity in plants, animals and humans reveals a similar mode of Al action in all living organisms, namely interference with the secondary messenger system (phosphoinositide and cytosolic Ca2+ signalling pathways) and enhanced production of reactive oxygen species resulting in oxidative stress. Aluminium uptake by plants is relatively quick (across the intact plasma membrane in < 30 min and across the tonoplast in < 1 h), despite huge proportion of Al being bound in the cell wall. Aluminium absorption in the animal/human digestive system is low (only about 0.1% of daily Al intake stays in the human body), except when Al is complexed with organic ligands (eg. citrate, tartarate, glutamate). Aluminium accumulates in bones and brain, with Al-citrate and Al-transferrin complexes crossing the blood-brain barrier and accumulating in brain cells. Tea plant and other Al-accumulator plant species contain large amounts of Al in the form of non-toxic organic complexes.
Rengel
Z
Z
Soil Science and Plant Nutrition, School of Earth and Geographical Sciences, The University of Western Australia, Crawley WA 6009, Perth, Australia. zrengel@agric.uwa.edu.au
D000535:Aluminum / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002473:Cell Wall; D002845:Chromatography; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008024:Ligands; D009474:Neurons / Q000378:metabolism; D018384:Oxidative Stress; D018521:Plant Physiological Phenomena; D010944:Plants / Q000378:metabolism; D017382:Reactive Oxygen Species; D015398:Signal Transduction; D012987:Soil; D013662:Tea; D013997:Time Factors
D008024:Ligands; D017382:Reactive Oxygen Species; D012987:Soil; D013662:Tea; D000535:Aluminum; D002118:Calcium