Manganese toxicity in tomato plants: Effects on cation uptake and distribution
Year: 1990
Type: article
Abstract: Two experiments are described in which tomato plants (Lycopersicon esculentum L. var Ailsa Craig) were grown in water culture supplied with 10–300 μM Mn. Toxicity symptoms associated with a yield reduction were observed only in treatments in excess of 50 μM Mn indicating that this species is relatively tolerant of high Mn supply. Dark brown/black spots appeared first in the cotyledons. Similar symptoms were observed in the leaves, progressively from the oldest leaf. Manganese concentration in the shoot tissues ranged from 286 to 4240 μg. g‐1 dry weight. The high Mn concentration values found in the shoot tissues of the toxic plants indicate that Mn was highly mobile in the xylem as confirmed by xylem sap analysis. The concentrations of both Ca and Mg were lower in the smaller Mn toxic plants. Not only was uptake of Ca and Mg retarded but so also was the distribution of Ca and Mg to the younger tissues as illustrated by measurements of Ca and Mg concentrations along a leaf age sequence. This is in accord with the cation‐anion balance of the xylem exudates collected from decapitated plants. Higher cation exchange capacity (CEC) was found in the leaf tissues of toxic plants particularly in the older leaves but similar values of C.E.C were recorded for the younger leaf tissues of both control and toxic plants.
Source: Journal of Plant Nutrition
Authors: J. Le Bot, E. A. Kirkby, M. L. van Beusichem
Institutions: University of Leeds, Wageningen University & Research
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W1976181642