Alteration in membrane tomato lipids (Solanum esculentum) induced by nitrite stress

Abstract

Plants of tomato (Solanum esculentum Mill. cv. Ibiza F1) are exposed to 0.25, 1, 2.5, 5 and 10 mM NO3- or NO2- through rooting medium during 7 days with the aim to study KNO 2- induces changes in biomass production and membrane lipid composition. Cultivated on the same doses of KNO3 plants serve as indicators. The accumulation of NO2- increases with external KNO2 concentrations, and is considerably higher in roots than in primary leaves. Biomass production of the growing leaves and roots is strongly depressed at higher KNO2 levels, which is associated with a significant decrease in content of total lipids and changes in fatty acid composition. Total lipids are more decreased in roots than in primary leaves. Also, significant decreases in content of global lipid fractions are recorded in elevated nitrite-stressed plants in comparison with controls. The contents of lipid components decline in all plant organs under NO2- treatment. However, amounts of phospholipid molecules are more affected in roots than in old leaves. Moreover, in all lipid classes, levels polyunsaturated acids decrease, and that of saturated (C16:0) one increase. Copyright © 2012 Société botanique de France.