Changes in essential oil composition and fatty acid profile of coriander (Coriandrum sativum L.) leaves under salinity and foliar-applied silicon

Abstract

Silicon (Si) has beneficial role in alleviating the adverse effects of salt stress on plant growth; however, its impacts on essential oil (EO) and fatty acid (FA) composition have not been well recognized. This study investigated the effect of Si and salinity on EO yield and composition as well as FA profile of coriander (Coriandrum sativum L.) leaves. Foliar application of 50, 100 and 200 mg L−1 Si and 50, 100, and 200 mM NaCl were applied on 4-leaf plants for 40 days. The results showed that salt-stressed plants experiencing 50 or 100 mM NaCl had higher EO yield. The EO yield increased by progressing Si concentration. The main EO constitutes were n-decanal (12.3-29.7%), 2E-dodecanal (12.1-22.1%), 2E-decanal (4.8-8.7%), 2E-tridecen-1-al (6.7-12.4%), and n-nonane (3.4-9.8%). Salt stress increased saturated fatty acids (SFAs) including palmitic acid (C16:0) and stearic acid (C18:0) and reduced monounsaturated fatty acids (MUFAs), oleic acid (C18:1), and polyunsaturated fatty acids (PUFAs), linoleic acid (C18:2) and linolenic acid (C18:3). The C16:0 and 2E-decanal increased by progressing the salt stress. However, salinity decreased the unsaturated fatty acids and n-decanal. Heat map analysis (HMA) showed 200 mM NaCl was significantly different from other treatments, which was mainly determined by n-nonane, n-decanal, and 2E-dodecanal. Principal component analysis (PCA) analysis showed all FAs, n-decanal, 2E-decanal were the main effective variables to show the changes of the treatments. Depending on the goals, it is possible to choose the best treatment of salinity and Si to reach the optimum amount of given compound.