Non-targeted metabolomic analysis for the comparative evaluation of volatile organic compounds in 20 globally representative cucumber lines

Hyo Eun Jo; Kihwan Song; Jeong-Gu Kim; Choong Hwan Lee

doi:10.3389/fpls.2022.1028735

Non-targeted metabolomic analysis for the comparative evaluation of volatile organic compounds in 20 globally representative cucumber lines

Front Plant Sci. 2022 Sep 29:13:1028735. doi: 10.3389/fpls.2022.1028735. eCollection 2022.

Authors

Hyo Eun Jo¹, Kihwan Song², Jeong-Gu Kim³, Choong Hwan Lee^{1

4}

Affiliations

¹ Department of Bioscience and Biotechnology, Konkuk University, Seoul, South Korea.
² Department of Bioresources Engineering, Sejong University, Seoul, South Korea.
³ Genomics Division, National Institute of Agricultural Sciences, Rural Development Administration, Jeonju, South Korea.
⁴ Research Institute for Bioactive-Metabolome Network, Konkuk University, Seoul, South Korea.

Abstract

Volatile organic compounds (VOCs) are one of the main fruit-quality determinants in cucumber. Here, we investigated the differences in the VOC and primary metabolite composition among 20 representative cucumber lines. Results of non-targeted metabolomics revealed that the cucumber breeding line of the Korean group showed a unique VOC composition in the fruit peel compared to the other groups. Fruit-flesh VOCs significantly differed among Korean, European, and Thai fruits. The main cucumber flavor components, 2-hexenal, hexanal, 6-nonenal, 2,4-nonadienal, and 2,6-nonadienal, were lower in the Korean cucumber lines than in the others. Conversely, linoleic acid derivatives and α-linolenic acid, which are precursors of these VOCs, were abundant in Korean cucumber line. This suggests that the metabolism related to the characteristic flavor of cucumber are downregulated in Korean cucumber line. This study provides novel insights into the fruit flavor-associated metabolome in various cucumber lines.

Keywords: Metabolomics; cucumber; fruit flavor; hydroperoxide lyase (HPL) and lipoxygenase (LOX) metabolisms; volatile organic compounds.