Elevated CO2 alleviates browning development by modulating metabolisms of membrane lipids, proline, and GABA in fresh-cut Asian pear fruit

ABSTRACT: The goal of this study was to elucidate the growth and development of the Asian pear fruit, on the grounds of length, diameter and fresh weight determined over time, using the non-linear Gompertz and Logistic models. The specifications of the models were assessed utilizing the R statistical software, via the least squares method and iterative Gauss-Newton process (DRAPER & SMITH, 2014). The residual standard deviation, adjusted coefficient of determination and the Akaike information criterion were used to compare the models. The residual correlations, observed in the data for length and diameter, were modeled using the second-order regression process to render the residuals independent. The logistic model was highly suitable in demonstrating the data, revealing the Asian pear fruit growth to be sigmoid in shape, showing remarkable development for three variables. It showed an average of up to 125 days for length and diameter and 140 days for fresh fruit weight, with values of 72mm length, 80mm diameter and 224g heavy fat.

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Moderation of respiratory cascades and energy metabolism of fresh-cut pear fruit in response to high CO2 controlled atmosphere

Postharvest Biology and Technology ◽

10.1016/j.postharvbio.2020.111379 ◽

2021 ◽

Vol 172 ◽

pp. 111379

Author(s):

Di Wang ◽

Quan Ma ◽

Dong Li ◽

Wenxuan Li ◽

Li Li ◽

...

Keyword(s):

Energy Metabolism ◽

Controlled Atmosphere ◽

Pear Fruit ◽

High Co2 ◽

Fresh Cut

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Respiratory and Glycolytic Response of Suspension-cultured `Passe Crassane' Pear Fruit Cells to Elevated CO2 Concentrations

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.115.1.111 ◽

1990 ◽

Vol 115 (1) ◽

pp. 111-114 ◽

Cited By ~ 13

Author(s):

Eduardo L. Kerbel ◽

Adel A. Kader ◽

Roger J. Romani

Keyword(s):

Cell Suspension ◽

Elevated Co2 ◽

Ethylene Production ◽

Inhibitory Effect ◽

Suspension System ◽

Glycolytic Pathway ◽

Close Similarity ◽

Pear Fruit ◽

L Cells ◽

Site Of Action

Suspension-cultured `Passe Crassane' pear fruit (Pyrus communis L.) cells in aging media were ventilated with air or air + 20% CO2 for 4 days at 26C. Cells exposed to elevated CO2 exhibited reduced respiration (02 consumption). Ethylene production of both air and CO2-treated cells also declined to barely discernible levels by day 3. Fructose 6-phosphate (F6P) accumulated, while levels of fructose l,6-bisphosphate (F1, 6-P2), and activities of ATP and PPi phosphofructokinases (PFK and PFP) declined in response to elevated CO2. These results indicate an inhibitory effect of CO2 at the site of action of both phosphofructokinases in the glycolytic pathway, which could account, at least in part, for the observed reduction in respiration. The responses to elevated CO2 levels of the cell suspension system and intact pear fruit ventilated with air + 10% CO2 are compared, revealing a close similarity.

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Comparative Transcriptomic Analyses Provide Insights into the Enzymatic Browning Mechanism of Fresh-Cut Sand Pear Fruit

Horticulturae ◽

10.3390/horticulturae7110502 ◽

2021 ◽

Vol 7 (11) ◽

pp. 502

Author(s):

Jing Fan ◽

Wei Du ◽

Qi-Liang Chen ◽

Jing-Guo Zhang ◽

Xiao-Ping Yang ◽

...

Keyword(s):

Molecular Mechanisms ◽

Transcript Level ◽

Enzymatic Browning ◽

Rna Seq ◽

Pear Fruit ◽

Total Polyphenol ◽

Phenylpropanoid Biosynthesis ◽

Key Enzyme ◽

Fresh Cut ◽

High Level

Pear (Pyrus spp.) is one of the most commonly consumed temperate fruits, having considerable economic and health importance. Fresh-cut or processed pear fruits are prone to browning because of the abundant phenolic compounds; however, little is known about the molecular mechanisms underlying enzymatic browning of fresh-cut sand pear fruit. In this study, fruits of two sand pear genotypes (low browning cultivar ‘Eli No.2′ and high browning cultivar ‘Weiningdahuangli’) were used to analyze the molecular mechanism of enzymatic browning by SMRT-seq and RNA-seq. The results generated 69,122 consensus isoforms, 21,336 new transcripts, 7105 alternative splicing events, and 254 long non-coding RNAs (lncRNAs). Furthermore, five genes related to enzymatic browning were predicted to be targets of six lncRNAs, and 9930 differentially expressed genes (DEGs) were identified between two different flesh browning cultivars. Meanwhile, most DEGs (e.g., PAL, 4CL, CAD, CCR, CHS, and LAR) involved in the phenylpropanoid biosynthesis pathway were up-regulated, and the expression of PPO and POD were highly expressed in the high-browning cultivar. Interestingly, the transcript level of PbrPPO4 (Pbr000321.4) was significantly higher than other PPO and POD genes, and a high level of total polyphenol and PPO activity were observed in the high browning cultivar. We found that the expression of lncRNA PB.156.1 was significantly positively correlated with the target gene PbrPPO4 (Pbr000321.4). The results suggest that PbrPPO4 might act as a major contributor and a key enzyme encoding gene in regulating fresh-cut sand pear fruit enzymatic browning; the expression of PbrPPO4 was probably regulated by lncRNA PB.156.1. Altogether, the transcriptomic and physiological analyses expand the knowledge of sand pear flesh enzymatic browning at the molecular level and provide a foundation for germplasm resources for molecular breeding of high polyphenol and low browning cultivars in sand pears.

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Investigation and Prevention of Cork Spot Disorder in ‘Akizuki’ Pear (Pyrus pyrifolia Nakai)

HortScience ◽

10.21273/hortsci13775-18 ◽

2019 ◽

Vol 54 (3) ◽

pp. 480-486 ◽

Cited By ~ 2

Author(s):

Yan-xin Duan ◽

Ying Xu ◽

Ran Wang ◽

Chun-hui Ma

Keyword(s):

Fruit Size ◽

Soluble Solids ◽

Pyrus Pyrifolia ◽

Pear Fruit ◽

Full Bloom ◽

Pear Cultivar ◽

Asian Pear ◽

High Concentrations ◽

Prohexadione Calcium ◽

Potential Tool

‘Akizuki’ (Pyrus pyrifolia Nakai) is a dominant Asian pear cultivar with gradually increasing cultivation area in Shandong province. However, this cultivar is found susceptible to cork spot disorder in recent years. In this study, we explored the physiological-biochemical mechanism of cork spot disorder in pear fruit, and investigated the effectiveness of spraying calcium (Ca), boron (B) solution or prohexadione calcium (P-Ca) on cork spot incidence. Cork spotted fruit had the characteristics of significantly larger fruit size with shorter fruit pedicels. Compared with normal fruit, cork spotted fruit had lower content of total soluble solids, soluble and reducing sugar, and vitamin C. In addition, cork spotted fruit accumulated much higher levels of N and Mg, and lower levels of K and P. However, Ca deficiency was not observed in cork spotted fruit, on the contrary, we determined high concentrations of Ca and free Ca2+ in disordered fruit. At the same time, the ratios of K/Ca, Mg/Ca, and (K+Mg)/Ca were significantly lower in cork spotted fruit as compared with normal fruit. Among all treatments, spraying with 3500 times dilution of P-Ca at 15-day intervals from 30 to 90 days after full bloom showed promise for reducing cork spot incidence in ‘Akizuki’ pear without affecting fruit quality attributes. This research herein reveals the physiological-biochemical characteristic of cork spot disorder, and implicates P-Ca as a potential tool to reduce cork spot incidence in Asian pear cultivar Akizuki.

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Developmental Changes in Carbohydrate Composition of Asian Pear Cultivars Grown in the Southeastern United States

HortScience ◽

10.21273/hortsci.31.4.684a ◽

1996 ◽

Vol 31 (4) ◽

pp. 684a-684

Author(s):

Nihal C. Rajapakse ◽

William C. Newall

Keyword(s):

Soluble Sugars ◽

Developmental Changes ◽

Sugar Composition ◽

Pear Fruit ◽

Full Bloom ◽

Mature Fruit ◽

Total Soluble Sugars ◽

Immature Fruit ◽

Early Maturation ◽

Asian Pear

Changes in sugar composition during maturation and ripening of eight Asian pear cultivars were evaluated. Total soluble sugars (TSS) increased gradually throughout the maturation and averaged 10% to 13% in mature fruit. All cultivars, except `Shinko' and `Nijisseiki', had accumulated ≥10% TSS by 100 days after full bloom (DAFB). Starch accumulated during early stages of Asian pear fruit development but decreased as the maturity progressed coinciding with the rise in soluble sugars. Sorbitol, a sugar alcohol, was predominant in immature fruit and accounted for 35% to 60% of TSS fraction depending on the cultivar. Fructose rapidly increased during early maturation. Glucose increased during early maturation, but the increase was much smaller than that of fructose. Sucrose was low (<4%) in immature fruit but accumulated rapidly late in the maturation and continued to increase until harvest. In mature `Hosui', `Kosui', `Nijisseiki', `Shinsui', `Shinko', and `Ichiban' fruit, fructose was the predominant sugar which accounted for 47% to 60% of the TSS fraction. Glucose and sucrose accounted for 13% to 17% and 7% to 12%, respectively, in those cultivars. In mature `Shinseiki' fruit, sucrose was the predominant sugar (44% of TSS), while fructose and glucose accounted for 33% and 8%, respectively. Sucrose and fructose were present in equal amounts (29%) in mature `Chojuro' fruit. Late accumulation of sucrose in Asian pear cultivars suggest that sufficient time should be allowed before harvesting to obtain sweeter fruit.

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