Decoding altitude-activated regulatory mechanisms occurring during apple peel ripening

Abstract

Apple (Malus domestica Borkh) is an important fruit crop cultivated in a broad range of environmental conditions. Apple fruit ripening is a physiological process, whose molecular regulatory network response to different environments is still not sufficiently investigated and this is particularly true of the peel tissue. In this study, the influence of environmental conditions associated with low (20 m) and high (750 m) altitude on peel tissue ripening was assessed by physiological measurements combined with metabolomic and proteomic analyses during apple fruit development and ripening. Although apple fruit ripening was itself not affected by the different environmental conditions, several key color parameters, such as redness and color index, were notably induced by high altitude. Consistent with this observation, increased levels of anthocyanin and other phenolic compounds, including cyanidin-3-O-galactoside, quercetin-3-O-rhamnoside, quercetin-3-O-rutinoside, and chlorogenic acid were identified in the peel of apple grown at high altitude. Moreover, the high-altitude environment was characterized by elevated abundance of various carbohydrates (e.g., arabinose, xylose, and sucrose) but decreased levels of glutamic acid and several related proteins, such as glycine hydroxymethyltransferase and glutamate-glyoxylate aminotransferase. Other processes affected by high altitude were the TCA cycle, the synthesis of oxidative/defense enzymes, and the accumulation of photosynthetic proteins. From the obtained data we were able to construct a metabolite-protein network depicting the impact of altitude on peel ripening. The combined analyses presented here provide new insights into physiological processes linking apple peel ripening with the prevailing environmental conditions.

Using Zinc Oxide Nanoparticles to Improve the Color and Berry Quality of Table Grapes Cv. Crimson Seedless

“…Anthocyanin pigment is responsible for Crimson seedless table grape berry coloration. This pigment is negatively affected by climate and differences between day and night temperature during the veraison stage [5] and it is also affected by the low altitude [6,7]. Various reasons for inferior color development in table grapes have been reported for the conditions prevalent in Egypt, such as high temperature [8,9]) and vigorous growth with dense, shaded canopies [10,11].…”

Influence of genetic background, growth latitude and bagging treatment on phenolic compounds in fruits of commercial cultivars and wild types of apples (Malus sp.)

“…The highest contents of total phenolic compounds, total flavonoids and total flavonols were found in the fruits from locations at the highest altitude (Mukhawa, 2780 m) than those from locations at lower altitudes [41]. A recently published research showed that variation in altitudeinduced changes in multiple biochemical pathways in apple peels of the cultivar 'Fujiku' during the fruit ripening [42]. Phenolic compounds of all the groups were increased at high altitude (750 m) compared to low altitude (20 m) accompanied by elevated expression of some key enzymes involved in the biosynthesis of these compounds.…”

Systems Biology Applied to the Study of Papaya Fruit Ripening: The Influence of Ethylene on Pulp Softening

“…It depends on the presence (climacteric) or absence (non-climacteric) of rise in respiration and ethylene production [2]. Ethylene coordinates the ripening process but is also known to regulate gene expression on several stages of fruit development [4][5][6]. The transduction pathway initiates when ethylene binds to a specific receptor, that will initiate the signaling cascade by releasing CTR1 and EIN2 binding, activating several transcription factors (EIN3/EIL1 and ERFs).…”

“…The transduction pathway initiates when ethylene binds to a specific receptor, that will initiate the signaling cascade by releasing CTR1 and EIN2 binding, activating several transcription factors (EIN3/EIL1 and ERFs). These transcription factors regulate genes underlying ripening-related traits, such as pulp firmness [2][3][4][5][6]. Ethylene exogenous treatment rapidly increases the transcription of 2 of 19 all these genes regulated by this hormone [5][6][7][8].…”

“…These transcription factors regulate genes underlying ripening-related traits, such as pulp firmness [2][3][4][5][6]. Ethylene exogenous treatment rapidly increases the transcription of 2 of 19 all these genes regulated by this hormone [5][6][7][8]. In this way, an effective methodology to investigate the expression profile during ripening is transcriptomics, which identifies the complete set of a sample's mRNA content.…”