Effects of Citrus Sudden Death Disease on Fatty Acid Profile of Orange Tree Bark

Abstract

Citrus sudden death (CSD) is a disease that has affected millions of orange trees in Brazil, leading to economic losses in the order of billions of US dollars. This article examines the effects of CSD on the fatty acid composition of triacylglycerides (TAG) extracted from rootstock and scion bark. The fatty acid profile determined by gas chromatography showed a reduction in oleic and linolenic acids, and an increase in the saturated fatty acids and linoleic acid content, which was in line with the severity of CSD. The reduction in linolenic acid content was related to its role in the biosynthesis of jasmonic acid, which is involved in responses to abiotic and biotic stresses, as well as senescence. These alterations in the fatty acid profile were also used to classify plants both with and without CSD symptoms by using chemometric means. This method represents an alternative to support the diagnosis of CSD disease.