Physiological and Biochemical Response of Tropical Fruits to Hypoxia/Anoxia

Abstract

Aerobic respiration and oxygen consumption are indicators of routine metabolic rate, and dissolved oxygen in plant tissues is one of the most important environmental factors affecting their survival. The reduction of available O2 leads to hypoxia which causes a limitation of the oxidative phosphorylation; when O2 is absent, tissues generate ATP by activating the fermentative glycolysis to sustain glycolysis in the absence of mitochondrial respiration, which results in the production of lactate. Overall, hypoxia was reported to often decrease the respiration rate (O2 uptake) and delay the climacteric rise of ethylene in climacteric fruits by inhibiting action, thus delaying their ripening. Much research has been done on the application of postharvest hypoxia and anoxia treatment to temperate fresh crops (controlled or modified atmosphere), however, very few reported on tropical commodities. Indeed, the physiological mode of action of low or absence of oxygen in fresh crops is not well understood; and the physiological and biochemical bases of the effects low or absence of O2 are also yet to be clarified. Recent investigations using omics technologies, however, have provided useful information on the response of fresh fruits and vegetables to this abiotic stress. The aims of this review are to (i) report on the oxygen exchange in the crops tissue, (ii) discuss the metabolic responses to hypoxia and anoxia, and (iii) report the physiological and biochemical responses of crops tissues to these abiotic stresses and the potential benefits of these environmental conditions.

Systematic Study of the Sensory Quality, Metabolomics, and Microbial Community of Fresh-Cut Watermelon Provides New Clues for Its Quality Control and Preservation

“…Despite a declined SSC value being observed in pulps that had been stored at RT for 72 h ( Figure 1 C), the contents of α-glucose, β-glucose, fructose, and sucrose were statistically stable within 72 h at the two set storage temperatures ( Figure 3 ). On the one hand, the soaring lactate indicated extremely active anaerobic glycolysis and glucose dissipation in pulp cells [ 32 ]. On the other hand, firmness loss might upregulate the concentration of sugars to a greater or lesser degree.…”

Physicochemical properties and transcriptional changes underlying the quality of ‘Gala’ apples (Malus × domestica Borkh.) under atmosphere manipulation in long‐term storage

“…Intense transcriptional reprogramming is observed in fruit under low oxygen pressures 13 . Hypoxia also affects directly ethylene biosynthesis and tissue responsiveness to the hormone 13,14 . The metabolic pathways most significantly affected by hypoxia are sucrose catabolism, anaerobic fermentation, and reactive oxygen species regulation, and current evidence indicates that low oxygen levels affect differently ripening and senescence metabolic process 34,35 …”

“…The responses to hypoxia in fruit tissues include a reduction in cellular respiration and ethanol biosynthesis, followed by the induction of anaerobic respiration, affecting the transport of metabolites and several energy‐associated pathways, including glycolysis, the cycle of tricarboxylic acids (TCA) and the metabolism of amino acids 13 . The reduction in cellular levels of O 2 also affect ethylene production and tissue sensitivity negatively 13,14 . As a consequence of the modifications in fruit physiological and metabolic processes, hypoxia delays ripening and senescence of fruit 14,15 .…”

“…The reduction in cellular levels of O 2 also affect ethylene production and tissue sensitivity negatively 13,14 . As a consequence of the modifications in fruit physiological and metabolic processes, hypoxia delays ripening and senescence of fruit 14,15 . However, the levels of O 2 restriction have to be carefully balanced to prevent senescence without causing physiological disorders leading to undesirable marketing characteristics 13–15 …”

Efficiency of pre‐process anoxia treatment on quality of fresh‐cut pineapples cv. ‘Phulae’ during storage

“…It is commonly recognised that fresh-cut fruits have higher respiratory rate than the corresponding intact fruits due to the physical injury from minimal process (Allong et al, 2001). Therefore, the short-term anoxia treatment could maintain total sugars content through the control of increased respiration rate (Benkeblia, 2021). Lara et al (2011) reported that the contents of sucrose, fructose and glucose in short-term anoxia-treated peaches remained unchanged when compared to untreated fruits.…”