Characterization of Fruit Quality Attributes and Cell Wall Metabolism in 1-Methylcyclopropene (1-MCP)-Treated ‘Summer King’ and ‘Green Ball’ Apples During Cold Storage

Abstract

This study aimed to elucidate whether 1-methylcyclopropene (1-MCP) treatment delays the fruit softening mechanism associated with the fruit quality of the newly released apple cultivars “Summer King” and “Green Ball” during cold storage. For both cultivars, the fruit treated with 1-MCP exhibited lower internal ethylene concentration, higher firmness, and higher titratable acidity relative to the control fruit, in association with less fruit softening. In addition, the treated fruit significantly delayed fresh weight loss and reduction of soluble solids content, especially in “Green Ball.” Moreover, slower degradation of cell wall components (water-soluble pectin, sodium carbonate-soluble pectin, hemicellulose, and cellulose) was also observed in the treated fruit in comparison to the control fruit. Similarly, the enzymatic activities (of polygalacturonase, pectin methylesterase, cellulase, β-galactosidase, and α-L-arabinofuranosidase) that cause cell wall degradation were relatively lower in the treated fruit than in the control fruit for both cultivars, which was further proved by transcriptional analysis of the genes encoding the enzymes. Overall, the results suggested that the usage of 1-MCP is useful to delay fruit softening of the two cultivars during cold storage by delaying the degradation of cell wall components and enzymatic activities of cell wall hydrolysis.

Constant storage temperature delays firmness decreasing and pectin solubilization of apple during post‐harvest storage

“…Red (positive) and blue (negative) correlations between analyses of respective values at *p < .05, **p < .01. The numbers in the boxes represented the correlation coefficients This was similar to observations made in other studies (Gwanpua et al, 2013;Johnston et al, 2001;Win et al, 2019;Yoo et al 2016) where ethylene had negative correlation with firmness. In addition, the ethylene production found in "Golden Delicious" was higher than that of "Fuji" apple.…”

“…One of the common points of these studies is that TFs will cause the firmness losing of various fruit and vegetable during storage. The loss of firmness negatively affects fruit quality traits, such as crisp texture, flavor, and appearance, facilitating physical damage and pathogen infections (Harker et al, 1997;Mohebbi et al, 2020;Win et al, 2019). Hence, it is interesting to investigate how cell wall polysaccharides, cell wall modifying enzymes and cell wall microstructures of apple (especially "Fuji" and "Golden Delicious" with different texture characteristics) varies during storage under different TFs.…”

“…The observation was taken at 3,000× magnification (bar = 1 μm). CW, cell wall; ML, middle lamella; PM, plasma membrane cultivars (Jung & Watkins, 2014;Win et al, 2019;Yoo et al, 2016).…”

Identification of Candidate Genes Involved in Fruit Ripening and Crispness Retention Through Transcriptome Analyses of a ‘Honeycrisp’ Population

“…In climacteric apple fruit, the amount of cellulose and hemicellulose are relatively constant during ripening [ 53 ], and cellulose synthase and cellulose synthase-like genes have not been the main foci to postharvest textural changes. In a recent study by Win et al [ 54 ], degradation of cellulose and hemicellulose, correlating with fruit softening, was observed in fruit of ’Summer King’ and ’Green Ball’ apples during long-term storage. Whether the continuous expression of cellulose synthase and cellulose synthase-like genes in fruit of ’Honeycrisp’ during storage contributes to crispness retention can be further evaluated in future research by measuring the cellulose and hemicellulose content in ’Honeycrisp’ fruit.…”

“…Among them, MdPG1 ( MD10G1179100 ) was the most prominent gene associated with losing crispness, as significantly high expression of MdPG1 was consistently observed in fruit of MN1764, the “Lose”, and the “Non-crisp” individuals ( Table 1 and Table 2 b). Polygalacturonases (PGs) catalyze the hydrolysis of pectin, and the expression of MdPG1 during fruit ripening has been correlated with increased pectin solubilization, which leads to softening of apple fruit [ 20 , 54 , 56 ]. Many studies have illustrated the roles of MdPG1 through different approaches, including the examination of MdPG1 in fruit of varieties with different firmness [ 16 ] and the study of transgenic apple with suppressed MdPG1 [ 57 ].…”