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Plant metal content, growth responses and some photosynthetic measurements on field‐cultivated wheat growing on ore bodies enriched in Cu
Author(s) -
Lanaras T.,
Moustakas M.,
Symeonidis L.,
Diamantoglou S.,
Karataglis S.
Publication year - 1993
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1993.tb05504.x
Subject(s) - rubisco , photosynthesis , dry weight , chlorophyll , chemistry , horticulture , chlorophyll fluorescence , botany , agronomy , biology
Some elemental levels, morphological and photosynthetic characteristics and cellular metabolites of wheat plants ( Triticum aestivum L. cv. Vergina) growing in the field on an ore body (Cu concentration in the soil 3050 ug g −1 ) were compared to control plants growing in the same environment where the Cu concentration in the soil was 140 μg g 1 . The concentrations of Cu, K, Pb, Zn, Mg and Fe were higher in the ore plants but Ca was lower. Growth of the ore plants was inhibited, with decreased height (25%), weight (5%), leaf area (7%) and leaf dry weight (5%) compared to the control plants. Leaf protein concentration of the ore plants was 16. 2 mg cm 2 leaf area, 63% of that of the control plants. The ore plants were chlorotic and chlorophyll concentration was 3. 8 μg cm −2 leaf area, 6. 4 times lower than that in the control plants. Ribulose 1. 5‐bisphosphate carboxylase/oxygenase (Rubisco, EC 4. 1. 1. 39) activity was 13. 4 μmol CO 2 fixed (mg dry weight) −1 min −1 , 164% of the activity in control plants. Therefore, growth inhibition did not appear to result from inhibition of the dark reactions of photosynthesis. High Rubisco activity appears to be maintained to permit maximal CO 2 fixation rates whenever energy is available. Parameters of chlorophyll fluorescence F m , F v , I 1/2 and F v /F m were lower in the ore‐grown plants than in control plants; F m was higher. These values indicate that there is a decrease in the pool size of the electron acceptors on the reducing side of photosystem II (PSII), a destruction of PSII centres and interference in the photochemistry of PSII. The nitrogen content, soluble sugars, starch and lipid content were lower in ore‐grown plants. Lower carbohydrate levels appear to result from low photosynthetic activity. The fatty acid composition of lipids was similar in both groups. A lower proportion of polyunsaturated fatty acids was found in the ore‐grown plants. Stress caused by high Cu concentration in the soil appears to affect the light reactions of photosynthesis leading to growth inhibition.