Lipoxygenase activity associated to fruit ripening and senescence in chayote (Sechium eduleJacq. Sw. cv. “virens levis”)

Abstract

Lipoxygenase (LOX) enzyme activity and their putative isoforms were investigated during postharvest life in chayote fruit (Sechium edule Jacq. Sw. cv. “virens levis”). Possible associations of LOX with fruit quality parameters are discussed. Five LOX isoforms were identified (SeLOX‐1 to −5) displaying different activity patterns during ripening and senescence as well as in roots, stems, and leaves. The probable role of SeLOX‐5 as a specific isoform linked to senescence was examined. The highest relative activity of LOX was registered in fruit tissue, followed by leaves, stem, and roots. Correlations were found between LOX and fruit composition variables such as the contents of linoleic (LA) and linolenic (LNA) acids, weight loss, CO2 and ethylene production rates. LOX activity, and LA and LNA concentration decreased from Day 1 to Days 13–17, when early seed germination events became visible, indicating a transition stage between late fruit ripening and early senescence characterized by a deteriorative process. Practical applications Detrimental effects on fruit composition variables such as dehydration, weight loss, wilting, and sprouting symptoms, have been reported as the main causes that reduce the commercial quality and shelf life in chayote fruit and prevent their export to distant markets. To the best of our knowledge, the association of lipoxygenase (LOX) enzymes to non‐climacteric fruit ripening—like chayote—or their loss of commercial quality during prolonged shelf life has not yet been described. This is the first study that explores the role of chayote LOX activity in fruit, identifies various specific LOX isoforms associated to ripening or to the senescence process and provides new evidence that supports the hypothesis that putative LOX isoforms might be related to several postharvest detrimental effects on chayote fruit. This information could be useful to food processors or packers to pursue better profitability and consumer satisfaction.

Nitric oxide-dependent regulation of sweet pepper fruit ripening

“…5). Several studies have indicated that LOX activity is involved in fruit ripening, which appears to be modulated by two phytohormones (ABA and ethylene) associated with aroma production and fruit quality (Zhang et al , 2009; Lv et al , 2014; Zhang et al , 2017; Del Ángel-Coronel et al , 2018).…”

Comprehensive Genomic Characterization and Expression Analysis of the Lipoxygenase Gene Family in Watermelon under Hormonal Treatments

“…Instead, ClLOX4, ClLOX5, and ClLOX16 showed increases in transcripts during the late stage of rind development, implying their regulatory roles in fruit ripening. Previous reports have revealed that the LOX activity is associated with membrane degradation during fruit ripening, and ethyl and butyl acetates would increase with fruit ripening [20,44]. Therefore, the continuous increase in the expression of LOX genes during fruit development may be associated with cell degradation and senescence during fruit ripening.…”

Lipoxygenase (LOX) in Sweet and Hot Pepper (Capsicum annuum L.) Fruits during Ripening and under an Enriched Nitric Oxide (NO) Gas Atmosphere

“…In chayote ( Sechium edule ) plants, five LOX isozymes were found, and their profiles were also differently modulated in roots, stems, and leaves as well as during the ripening of fruit and senescence. Thus, at fruit ripening, three LOX isozymes were recognized, but after senescence occurred a new LOX appeared [ 34 ]. In sweet pepper plant organs, a total of seven LOX isozymes were identified using C18:2 as substrate, the shoot was the organ with the higher number of isozymes, whereas green fruits only contained one unique LOX isozyme, particularly the isozyme LOX IV.…”