Estudo do perfil químico de compostos orgânicos produzidos por variedades de tomates com diferentes resistências ao ataque de mosca-branca (Bemisia tabací)

Abstract

Tomato (Solanum lycopersicum) is one of the most cultivated vegetables around the world. However, producers face great risks in cultivation due to the attack of pests such as the whitefly (Bemisia tabaci). To overcoming these problems, companies have developed resistant tomato varieties to several pests. This work aims to analyze the chemical profile of Volatile Organic Compounds (VOCs) and Non-Volatile Organic Compounds (CONVS) produced by two tomato varieties, wich diferents resistence against whitefly [Dylla (TD) - resistant and Norty (TN)- non-resistant], when exposed or not to herbivory. VOCs were collected through fibers by Solid Phase Microextraction and analyzed by Gas Chromatography coupled to Mass Spectrometry (GC-MS). CONVs were obtained from the ethanolic extract of fresh leaves crushed with ethanol and subjected to GC-MS, Ultra-Performance Liquid Chromatography coupled with Sequential Mass Spectrometry (UPLC-MS/MS) and Nuclear Magnetic Resonance (NMR) analyses. The results obtained in the identification chemical compounds present in tomato leaves were statistically evaluated. The statistical analysis confirmed the difference in tomato varieties metabolites and showed that TD produced trans-carvenone oxide (43), a VOC not identified for TN variety. When infested with whitefly, Dylla tomato plants produced large amounts of 8-2-carene (4); and the Norty variety showed the highest amount of a-humulene (70) and the unidentified compound 65. The analysis of the extracts by GC-MS showed that the tomato plants produced mainly fatty acids and esters in the two experimental conditions (exposed/garden and not exposed to herbivory/greenhouse). The data from the analyzes by CLUE-MS/MS were processed on the GNPS platform, resulting in the annotation of 21 compounds (mainly flavonoids, terpenoids and phenylpropanoids). By 'H, 13C NMR and HSQC and HMBC contour maps it was possible to confirm the phytol compound structure (94) and the flavonoids quercetin-3-0-rutinoside (98) and quercetin (118). Thus, concluded that the TD and TN tomato varieties produce different compounds, which can be candidates for semiochemicals and applied in controlled trials to determine the bioerbicide efficiency in combating the whitefly.