Alteration in leaf lipid profile of zinc deficient bean seedlings
2002
Khalil, I.A. | Iqbal, A. | Saleemullah (NWFP Agricultural Univ., Peshawar (Pakistan). Dept. of Agricultural Chemistry)
The leaf phospholipids, glycolipids and sterol contents of bean (Phaseolus vulgaris) seedlings grown hydroponically with and without Zinc (Zn), were studied to test the hypothesis that lipid peroxidation occur in the absence Zn. It was observed that Zn-deficiency significantly (P less than 0.05) reduced the various lipid fractions. The Protein content was also decreased in the absence of Zn. Fatty acid profile of the phospholipids revealed a decline in the amount of unsaturated fatty acids in Zn-deficient plants. This confirms oxidative desaturation of the double bonds of unsaturated fatty acids. The leaf sterol composition was also affected by Zn- deficiency. The amount of 24-methyl sterol (campesterol) relative to 24-ethyl sterols (sitosterol and stigmasterol) was increased in Zn-restricted seedlings. This suggests that the second alkylation reaction of the phytosterol side- chain at C-24 was affected by Zn-deficiency. Changes in sterol profile might be responsible for increased permeability and leakage of the bio-membrane.
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