Progress toward Understanding the Molecular Basis of Fruit Response to Hypoxia

Abstract

Oxygen has shaped life on Earth as we know it today. Molecular oxygen is essential for normal cellular function, i.e., plants need oxygen to maintain cellular respiration and for a wide variety of biochemical reactions. When oxygen levels in the cell are lower than levels needed for respiration, then the cell experiences hypoxia. Plants are known to experience root hypoxia during natural environmental conditions like flooding. Fruit, on the other hand, is known to be hypoxic under normal oxygen conditions. This observation could be explained (at least partially) as a consequence of diffusional barriers, low tissue diffusivity, and high oxygen consumption by respiration. From the physiological point of view, hypoxia is known to have a profound impact on fruit development, since it is well documented that a low oxygen environment can significantly delay ripening and senescence of some fruit. This effect of a low-oxygen environment is readily used for optimizing storage conditions and transport, and for prolonging the shelf life of several fruit commodities. Therefore, further understanding of the complex relationship between oxygen availability within the cell and fruit development could assist postharvest management.

The hypoxia–reoxygenation stress in plants

“…For instance, O 2 -dependent signaling seems to control the timing and effective coordination for bud burst in grapevine ( Meitha et al , 2018 ). Besides the potential roles in developmental phase transitions, hypoxia is a natural condition for some plant storage tissues or organs such as fruits ( Rolletschek et al , 2002 ; Cukrov, 2018 ; Xiao et al , 2018 ). Multiple pieces of metabolic evidence support the development of hypoxic niches in diverse organs/tissues in plants ( Armstrong et al , 2019 ).…”

Microstructural changes enhance oxygen transport in tomato (Solanum lycopersicum) fruit during maturation and ripening

“…As a result, cells in those tissues may become subject to a hypoxic or even anoxic environment, and local cell death may result. This situation has been found in pear and apple fruit, where tissue breakdown and cavity formation have been observed in low O 2 storage (Franck et al ., 2007; Cukrov, 2018; Boeckx et al ., 2019). Likewise, cell death was observed in anoxic pericarp tissue of seeded grape berries during ripening (Tilbrook & Tyerman, 2008; Xiao et al ., 2018).…”

Biodegradable Food Packaging Materials and Prospects of the Fourth Industrial Revolution for Tomato Fruit and Product Handling

“…High levels of CO 2 can limit the activities of cell wall hydrolase enzymes and allow retention of the firmness during storage [ 23 ]. This effect of a low-oxygen environment is readily used for optimizing storage conditions and transport and for prolonging the shelf life of several fruit commodities [ 37 ]. Decreasing respiration rates of coated tomatoes could be responsible for delayed ripening and can result in reduced changes in physiological weight loss, color, titratable acidity, and retention of firmness [ 23 ].…”