Cell Wall Changes Associated with Normal and Mealy Fruit Softening for a Novel Peach Genotype

The `Stony Hard' gene of peach conferred a unique ability to manipulate softening and textural properties of the fruit by controlling the concentration and duration of exposure to ethylene. Fruit ripened in ethylene-free air softened very slowly. Exposure of fruit to 1 ppm ethylene continuously for 48 h, or discontinuously at 100 ppm over the same time period, significantly accelerated softening—to a normal texture. Exposure of fruit to 100 ppm ethylene continuously for 48 h induced softening to the same level, but to a mealy texture. We have prepared cell walls and conducted sequential chemical extractions from fruit exposed to the ethylene treatments above. Galacturonic acid content of chelator soluble pectin fractions decreased for mealy fruit, compared to fruit with normal texture, indicating that selective pectin degradation was associated with mealiness. Other differences in polysaccharide sugar composition and apparent molecular size associated with slow, accelerated, and abnormal softening in peach fruit will be addressed.

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INDUCTION OF MEALINESS DURING SHORT-TERM STORAGE FOR A NOVEL PEACH GENOTYPE

HortScience ◽

10.21273/hortsci.30.3.434a ◽

1995 ◽

Vol 30 (3) ◽

pp. 434a-434 ◽

Cited By ~ 1

Author(s):

Niels O. Maness ◽

Donna Chrz ◽

Joseph C. Goffreda

Keyword(s):

Quantitative Methods ◽

Textural Properties ◽

Soluble Solids ◽

Short Term ◽

Peach Fruit ◽

Free Air ◽

Agricultural Experiment ◽

Soluble Polysaccharide ◽

Term Storage ◽

Stony Hard

The peach mutation `Stony Hard' confers a slow softening attribute to the fruit and also confers a highly reproducible predisposal of fruit to soften abnormally to a mealy texture. Induction of mealiness required continuous 48-hour 100-ppm ethylene exposure. `Stony Hard' fruit exposed to low ethylene concentrations (l ppm) or discontinuous 100 ppm ethylene softened more rapidly than fruit exposed to ethylene-free air but to a normal texture. Ethylene treatment failed to induce mealiness in selections without the `Stony Hard' gene. As quantitative methods for assessment of mealiness, mesocarp-extractable juice decreased, and buffer soluble solids and soluble polysaccharide galacturonic acid content increased for mealy fruit. `Stony Hard' peach fruit represent the only known system in which the concentration and duration of exposure to ethylene can be used to manipulate softening and textural properties of the fruit. Supported by U.S. Dept. of Agriculture grant 93-34150-8409 and the Oklahoma Agricultural Experiment Station.

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Sugar Composition of Pectin and Hemicellulose Extracts of Peach Fruit during Softening over Two Harvest Seasons

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.121.6.1162 ◽

1996 ◽

Vol 121 (6) ◽

pp. 1162-1167 ◽

Cited By ~ 16

Author(s):

Supreetha Hegde ◽

Niels O. Maness

Keyword(s):

Cell Walls ◽

Potassium Hydroxide ◽

Fruit Softening ◽

Cell Wall Polysaccharides ◽

Peach Fruit ◽

Mole Percent ◽

Mole Percentage ◽

Three Stages ◽

Compositional Changes ◽

Inactive Cell

Changes in cell wall polysaccharides associated with peach fruit softening were characterized over two harvest seasons. Enzymically inactive cell walls were prepared from mesocarp tissues of peach fruit harvested at three stages of softening. Pectin-associated and hemicellulose-associated polysaccharides were extracted from the cell walls sequentially, and glycosyl residue compositions were determined by GLC. Pectin extracts from both years were richest in galacturonosyl, arabinosyl, and rhamnosyl residues. Hemicellulose extracted with 1 m potassium hydroxide contained a high mole percentage of xylosyl, glucosyl, and fucosyl residues. Hemicellulose extracted with 4 m potassium hydroxide contained a substantial amount of pectin-associated sugar residues in addition to hemicellulose-associated sugar residues. During softening in both years, sugar compositions for cell walls, aqueous phenol-soluble polysaccharides, and imidazole extracts reflected a decrease in galacturonosyl residues and a concomitant increase in arabinosyl residues on a mole percent basis. The degree of change for galacturonosyl residues in these fractions depended on season, with greater variation exhibited from fruit at earlier stages of softening. With the notable exception of the seasonal variation exhibited for galacturonosyl residues in cell walls, the relative stability of other glycosyl compositional changes over seasons indicates conserved changes for pectins and hemicelluloses occur during peach fruit softening.

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Sugar Composition of Cucumber Cell Walls During Fruit Development

Journal of Food Science ◽

10.1111/j.1365-2621.1987.tb14260.x ◽

1987 ◽

Vol 52 (4) ◽

pp. 996-1001 ◽

Cited By ~ 20

Author(s):

R. F. McFEETERS ◽

L. A. LOVDAL

Keyword(s):

Fruit Development ◽

Cell Walls ◽

Sugar Composition

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Ethylene and fruit softening in the stony hard mutation in peach

Postharvest Biology and Technology ◽

10.1016/j.postharvbio.2006.03.006 ◽

2006 ◽

Vol 41 (1) ◽

pp. 16-21 ◽

Cited By ~ 51

Author(s):

Hiroko Hayama ◽

Miho Tatsuki ◽

Akiko Ito ◽

Yoshiki Kashimura

Keyword(s):

Fruit Softening ◽

Stony Hard

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Characterization and Transcript Profiling of PME and PMEI Gene Families during Peach Fruit Maturation

Journal of the American Society for Horticultural Science ◽

10.21273/jashs04039-17 ◽

2017 ◽

Vol 142 (4) ◽

pp. 246-259 ◽

Cited By ~ 3

Author(s):

Yunqing Zhu ◽

Wenfang Zeng ◽

Xiaobei Wang ◽

Lei Pan ◽

Liang Niu ◽

...

Keyword(s):

Fruit Ripening ◽

Prunus Persica ◽

Expression Patterns ◽

Pectin Methylesterase ◽

Gene Families ◽

Naphthaleneacetic Acid ◽

Regulation Mechanism ◽

Fruit Softening ◽

Peach Fruit

Pectins are synthesized and secreted to the cell wall as highly methyl-esterified polymers and demethyl-esterified by pectin methylesterases (PMEs), which are regulated by pectin methylesterase inhibitors (PMEIs). PMEs and PMEIs are involved in pectin degradation during fruit softening; however, the roles of the PME and PMEI gene families during fruit softening remain unclear. Here, 71 PME and 30 PMEI genes were identified in the peach (Prunus persica) genome and shown to be unevenly distributed on all eight chromosomes. The 71 PME genes comprised 36 Type-1 PMEs and 35 Type-2 PMEs. Transcriptome analysis showed that 11 PME and 15 PMEI genes were expressed during fruit ripening in melting flesh (MF) and stony-hard (SH) peaches. Three PME and five PMEI genes were expressed at higher levels in MF than in SH fruit and exhibited softening-associated expression patterns. Upstream regulatory cis elements of these genes related to hormone response, especially naphthaleneacetic acid and ethylene, were investigated. One PME (Prupe.7G192800) and two PMEIs (Prupe.1G114500 and Prupe.2G279800), and their promoters were identified as potential targets for future studies on the biochemical metabolism and regulation of fruit ripening. The comprehensive data generated in this study will improve our understanding of the PME and PMEI gene families in peach. However, further detailed investigation is necessary to elucidate the biochemical function and regulation mechanism of the PME and PMEI genes during peach fruit ripening.

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