Introgression and Environmental Effects on Gene Expression and Aroma Volatiles As Biomarkers in a Melon Near-Isogenic Line

Abstract

This review paper discusses a study aimed at determining the aroma profile and global quality of a non-climacteric near-isogenic line (NIL) SC10-2 of melon and identifying the most discriminant flesh aroma volatiles at harvest as potential biomarkers of textural differences. The introgression in the linkage group X allows the NIL SC10-2 to behave differently, changing the non-climacteric behavior by producing aroma volatiles characteristic of non-climacteric lines or inhibiting the production of some compounds important for ripening. The study identifies thirty-two volatiles organic compounds (VOCs) that show correlation with textural traits in season 1, while in season 2, forty-one VOCs were identified. This paper also discusses the impact of environmental effects and introgression effects on VOCs and textural traits. Transcriptomic analysis from RNA-Seq revealed 2954 differentially expressed genes (DEGs) having introgression or introgression x ripening time effects and 2068 DEGs postharvest ripening time effect. The study also identifies at least thirtyfour genes affecting direct and/or indirectly in the delay of ripening of SC10-2 versus PS in general and particularly to respiration rate, ethylene production, textural traits and volatile production and probably differential non-climacteric response.