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Elevated root zone dissolved inorganic carbon can ameliorate aluminium toxicity in tomato seedlings
Author(s) -
Cramer M. D.,
Titus C. H. A.
Publication year - 2001
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.0028-646x.2001.00235.x
Subject(s) - dissolved organic carbon , lycopersicon , chemistry , nutrient , relative growth rate , horticulture , organic acid , phytotoxicity , aeration , nitrogen , botany , biology , environmental chemistry , growth rate , biochemistry , geometry , mathematics , organic chemistry
Summary• The potential amelioration of Al (Al) toxicity by elevated dissolved inorganic carbon (DIC = CO 2 + HCO 3 − ) in the root medium was investigated in both NH 4 + ‐ and NO 3 − ‐fed Lycopersicon esculentum (tomato) plants. • Hydroponically grown L. esculentum seedlings were intermittently supplied with 50 µM AlCl 3 and the nutrient solutions aerated with either 360 or 5000 ppm CO 2 . Relative growth rate (RGR), nitrogen uptake, root respiration and root incorporation of DI 14 C and subsequent partitioning were measured. • Al reduced the RGR of plants grown with 360 ppm root‐zone CO 2 . At elevated root‐zone CO 2 , Al had no significant effect on the RGR of NO 3 − ‐fed plants whereas the RGR of the NH 4 + ‐fed plants was increased by 21%. Al decreased the respiratory quotient (Rq) by 15% at 360 ppm CO 2 , but had no influence at 2000 ppm CO 2 . Exudation of organic 14 C, especially of [ 14 C]‐organic acids derived from root incorporation of DI 14 C, was increased by Al. • It is concluded that elevated DIC partially ameliorated Al toxicity by providing anaplerotic carbon for organic acid synthesis.