Phenotyping 172 strawberry genotypes for water soaking reveals a close relationship with skin water permeance.

Water soaking is a commercially important disorder of field-grown strawberries that is exacerbated by surface wetness and high humidity. The objective was to establish the effect of genotype on susceptibility to water soaking. Three greenhouse-grown model 'collections' were used comprising a total of 172 different genotypes: (1) a segregating F2 population, (2) a collection of strawberry cultivars and breeding clones, and (3) a collection of wild species.

Cuticle deposition ceases during strawberry fruit development.

Background: Ideally, the barrier properties of a fruit's cuticle persist throughout its development. This presents a challenge for strawberry fruit, with their rapid development and thin cuticles. The objective was to establish the developmental time course of cuticle deposition in strawberry fruit.

Constitutive expression of apple endo-POLYGALACTURONASE1 in fruit induces early maturation, alters skin structure and accelerates softening.

During fruit ripening, polygalacturonases (PGs) are key contributors to the softening process in many species. Apple is a crisp fruit that normally exhibits only minor changes to cell walls and limited fruit softening. Here, we explore the effects of PG overexpression during fruit development using transgenic apple lines overexpressing the ripening-related endo-POLYGALACTURONASE1 gene.

Microcracking of strawberry fruit cuticles: mechanism and factors.

Microscopic cracks in the cuticle (microcracks) are the first symptom of the strawberry fruit disorder 'water soaking' in which the fruit surface appears watery, translucent, and pale. Water soaking severely impacts fruit quality. The objective was to investigate the factors and mechanisms of cuticular microcracking in strawberry.

Time course of changes in the transcriptome during russet induction in apple fruit.

Background: Russeting is a major problem in many fruit crops. Russeting is caused by environmental factors such as wounding or moisture exposure of the fruit surface. Despite extensive research, the molecular sequence that triggers russet initiation remains unclear.

Lenticels are sites of initiation of microcracking and russeting in 'Apple' mango.

The mango cultivar 'Apple' is an important fruitcrop in Kenya, but it is highly susceptible to russeting. The objective was to establish whether lenticels predispose cv. 'Apple' mango to russeting.

Neck shrivel in European plum is caused by cuticular microcracks, resulting from rapid lateral expansion of the neck late in development.

Susceptibility to neck shrivel in European plum is due to cuticular microcracking resulting from high surface area growth rates in the neck region, late in development. Susceptibility to the commercially important fruit disorder 'neck shrivel' differs among European plum cultivars. Radial cuticular microcracking occurs in the neck regions of susceptible cultivars, but not in non-susceptible ones, so would seem to be causal.

Growth strains cause vascular browning and cavities in ´Nicoter´ apples.

'Nicoter' apples (Malus × domestica Borkh.) occasionally develop a disorder referred to as vascular browning. Symptomatic fruit are perceived as being of low quality.

Necked strawberries are especially susceptible to cracking.

Fruit cracking is a commercially important disorder that reduces both quantity and quality of strawberries ( × Duch.). The objective was to identify the physiological mechanism of cracking and the factors affecting cracking.

Detached, wetted strawberries take up substantial water in the calyx region.

In strawberry, surface disorders like 'water soaking', 'cracking' and 'shrivel' impair fruit quality of this high value crop. Water movement through the fruit surface is implicated a role in these disorders. The objective was to identify the pathways of water uptake and water loss (transpiration) and to identify factors affecting these flows.

Calcium decreases cell wall swelling in sweet cherry fruit.

Swelling of epidermal cell walls decreases cell-to-cell adhesion and increases cracking susceptibility in sweet cherry. Ca is suggested to decrease cracking susceptibility by crosslinking of cell wall components and, possibly, by decreasing swelling. The objective is to test this hypothesis.

Apple fruit periderms (russeting) induced by wounding or by moisture have the same histologies, chemistries and gene expressions.

Russeting is a cosmetic defect of some fruit skins. Russeting (botanically: induction of periderm formation) can result from various environmental factors including wounding and surface moisture. The objective was to compare periderms resulting from wounding with those from exposure to moisture in developing apple fruit.

Calcium ions decrease water-soaking in strawberries.

Water soaking is a common disorder of field-grown strawberries (Fragaria × ananassa Duch.). It develops when ripe fruit is exposed to rain.

Xylogenesis and phloemogenesis in the flesh of sweet cherry fruit are limited to early-stage development.

Water inflows into sweet cherry fruit occur via the xylem and the phloem vasculatures of the pedicel. The rates of these inflows are subject to marked changes during fruit development. The objective was to establish if, and when, xylogenesis and phloemogenesis occur in the fruit flesh (mesocarp) during fruit development.

Sweet cherry flesh cells burst in non-random clusters along minor veins.

Sweet cherry flesh cells burst when exposed to water but they do so in clusters indicating heterogeneity with respect to osmotic concentration, which depends on proximity to a minor vein. Water plays a key role in cracking in sweet cherry fruit. Magnetic resonance imaging has previously indicated preferential partitioning of water along veins.

Direct Evidence for a Radial Gradient in Age of the Apple Fruit Cuticle.

The pattern of cuticle deposition plays an important role in managing strain buildup in fruit cuticles. Cuticular strain is the primary trigger for numerous fruit-surface disorders in many fruit crop species. Recent evidence indicates a strain gradient may exist within the apple fruit cuticle.

Low cuticle deposition rate in 'Apple' mango increases elastic strain, weakens the cuticle and increases russet.

Russeting compromises appearance and downgrades the market value of many fruitcrops, including of the mango cv. 'Apple'. The objective was to identify the mechanistic basis of 'Apple' mango's high susceptibility to russeting.

Water Soaking Disorder in Strawberries: Triggers, Factors, and Mechanisms.

Water soaking is an important surface disorder of strawberries that limits unprotected field production. The objective was to identify the mechanism(s) of water soaking. Symptomatic fruit show pale, deliquescent patches of skin.

Penetration of sweet cherry skin by Ca-salts: pathways and factors.

Calcium is beneficial to sweet cherry physiology. The objective was to investigate factors affecting uptake of Ca into mature sweet cherry fruit through their skins. Penetration of Ca-salts was monitored using whole fruit or excised fruit skins mounted in diffusion cells.

Xylem, phloem and transpiration flows in developing European plums.

Neck shrivel is a quality disorder of European plum (Prunus × domestica L.). It has been suggested that backflow in the xylem (from fruit to tree) could contribute to the incidence of neck shrivel in plum.

Strawberry fruit skins are far more permeable to osmotic water uptake than to transpirational water loss.

Water movements through the fruit skin play critical roles in many disorders of strawberry (Fragaria × ananassa Duch.) such as water soaking, cracking and shriveling. The objective was to identify the mechanisms of fruit water loss (dry skin, transpiration) and water uptake (wet skin, osmosis).

Cutin Synthesis in Developing, Field-Grown Apple Fruit Examined by External Feeding of Labelled Precursors.

An intact skin is essential in high-quality apples. Ongoing deposition of cuticular material during fruit development may decrease microcracking. Our objective was to establish a system for quantifying cutin and wax deposition in developing apple fruit.

Correction: Crack initiation and propagation in sweet cherry skin: A simple chain reaction causes the crack to 'run'.

[This corrects the article DOI: 10.1371/journal.pone.

Russeting in Apple is Initiated after Exposure to Moisture Ends: Molecular and Biochemical Evidence.

Exposure of the fruit surface to moisture during early development is causal in russeting of apple ( × Borkh.). Moisture exposure results in formation of microcracks and decreased cuticle thickness.

Decreased deposition and increased swelling of cell walls contribute to increased cracking susceptibility of developing sweet cherry fruit.

During fruit development, cell wall deposition rate decreases and cell wall swelling increases. The cell wall swelling pressure is very low relative to the fruit's highly negative osmotic potential. Rain cracking of sweet cherry fruit is preceded by the swelling of the cell walls.