TY - JOUR

T1 - Sweet cherry flesh cells burst in non-random clusters along minor veins

AU - Brinkmann, Tobias

AU - Kuhnke, Felix

AU - Grimm, Eckhard

AU - Knoche, Moritz

N1 - Funding Information: Open Access funding enabled and organized by Projekt DEAL. This study was funded in part by the grant KN 402/10-1 from the German Science Foundation (DFG). Acknowledgmets: We thank Dr. Alexander Lang and Dr. Andreas Winkler for useful comments on an earlier version of this manuscript.

PY - 2022/5

Y1 - 2022/5

N2 - Main conclusion: 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. Abstract: Water plays a key role in cracking in sweet cherry fruit. Magnetic resonance imaging has previously indicated preferential partitioning of water along veins. A more negative osmotic potential along veins seems the likely explanation. Here we establish if cell bursting in mature sweet cherry fruit is also associated with the veins. Cell bursting was identified by a novel light microscope technique involving exposure of a cut fruit surface to water or to sucrose solutions. Upon exposure to water there was no bursting of skin cells but for cells of the flesh (mesocarp) bursting increased with time. When the cut surface was exposed to sucrose solutions of decreasing osmotic concentrations (increasing water potentials) the incidence of cell bursting increased from hypertonic (no bursting), to isotonic, to hypotonic. Cell bursting in the outer mesocarp occurred primarily in the vicinity of minor veins that in the inner mesocarp was primarily between radial veins. The median distance between a minor vein and a bursting cell (mean diameter 0.129 mm) was about 0.318 mm that between a radial vein and a bursting cell was about 0.497 mm. In contrast, the distance between adjacent minor veins averaged 2.57 mm, that between adjacent radial veins averaged 0.83 mm. Cell bursting tends to occur in clusters. Mapping of cell bursting indicates (1) that a seemingly uniform population of mesocarp cells actually represents a heterogeneous population with regard to their cell osmotic potentials and (2) cell bursting afflicts clusters of neighbouring cells in the vicinities of minor veins.

AB - Main conclusion: 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. Abstract: Water plays a key role in cracking in sweet cherry fruit. Magnetic resonance imaging has previously indicated preferential partitioning of water along veins. A more negative osmotic potential along veins seems the likely explanation. Here we establish if cell bursting in mature sweet cherry fruit is also associated with the veins. Cell bursting was identified by a novel light microscope technique involving exposure of a cut fruit surface to water or to sucrose solutions. Upon exposure to water there was no bursting of skin cells but for cells of the flesh (mesocarp) bursting increased with time. When the cut surface was exposed to sucrose solutions of decreasing osmotic concentrations (increasing water potentials) the incidence of cell bursting increased from hypertonic (no bursting), to isotonic, to hypotonic. Cell bursting in the outer mesocarp occurred primarily in the vicinity of minor veins that in the inner mesocarp was primarily between radial veins. The median distance between a minor vein and a bursting cell (mean diameter 0.129 mm) was about 0.318 mm that between a radial vein and a bursting cell was about 0.497 mm. In contrast, the distance between adjacent minor veins averaged 2.57 mm, that between adjacent radial veins averaged 0.83 mm. Cell bursting tends to occur in clusters. Mapping of cell bursting indicates (1) that a seemingly uniform population of mesocarp cells actually represents a heterogeneous population with regard to their cell osmotic potentials and (2) cell bursting afflicts clusters of neighbouring cells in the vicinities of minor veins.

KW - Cracking

KW - Osmotic potential

KW - Phloem

KW - Prunus avium

KW - Solute potential

KW - Water uptake

UR - http://www.scopus.com/inward/record.url?scp=85128221745&partnerID=8YFLogxK

U2 - 10.1007/s00425-022-03882-7

DO - 10.1007/s00425-022-03882-7

M3 - Article

C2 - 35389118

AN - SCOPUS:85128221745

VL - 255

JO - PLANTA

JF - PLANTA

SN - 0032-0935

IS - 5

M1 - 100

ER -