title: Water loss from litchi (Litchi chinensis) and longan (Dimocarpus longan) fruits is biphasic and controlled by a complex pericarpal transpiration barrier.
abstract: In litchi and longan fruits, a specialised pericarp controls water loss by a protective system consisting of two resistances in series and two water reservoirs separated by a barrier. In the fruits of litchi (Litchi chinensis) and longan (Dimocarpus longan), the pericarp is solely a protective structure lacking functional stomata and completely enclosing the aril that is the edible part. Maintaining a high water content of the fruits is crucial for ensuring the economic value of these important fruit crops. The water loss rates from mature fruits were determined and analysed in terms of the properties of the pericarps. Water loss kinetics and sorption isotherms were measured gravimetrically. The pericarps were studied with microscopy, and cuticular waxes and cutin were analysed with gas chromatography and mass spectrometry. The kinetics of fruit water loss are biphasic with a high initial rate and a lower equilibrium rate lasting for many hours. The outer and inner surfaces of the pericarps are covered with cuticles. Litchi and longan fruits have a unique type of transpiration barrier consisting of two resistances in series (endo- and exocarp cuticles) and two reservoirs of water (aril and mesocarp). The exocarp permeability controls the water loss from fresh fruits while in fruits kept for an extended time at low relative humidity it is determined by the endo- and exocarp permeabilities. Permeances measured are within the range for typical fruit cuticles. The findings may be used to design optimal postharvest storage strategies for litchi and longan fruits.
authors.affiliation: Julius von Sachs Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Pl. 3, 97082, Würzburg, Germany. riederer@uni-wuerzburg.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Riederer
authors.affiliation: Julius von Sachs Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Pl. 3, 97082, Würzburg, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Arand
authors.affiliation: Julius von Sachs Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Pl. 3, 97082, Würzburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Burghardt
authors.affiliation: Julius von Sachs Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Pl. 3, 97082, Würzburg, Germany.|South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou, 510650, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Huang
authors.affiliation: Julius von Sachs Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Pl. 3, 97082, Würzburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Riedel
authors.affiliation: Julius von Sachs Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Pl. 3, 97082, Würzburg, Germany.
authors.forename: Ann-Christin
authors.initials: AC
authors.lastname: Schuster
authors.affiliation: Julius von Sachs Institute of Biological Sciences, University of Würzburg, Julius-von-Sachs-Pl. 3, 97082, Würzburg, Germany.|Génétique Moléculaire, Génomique, Microbiologie, Institut de Physiologie et de la Chimie Biologique, Université de Strasbourg, 21 rue René Descartes, 67084, Strasbourg Cedex, France.
authors.forename: Anna
authors.initials: A
authors.lastname: Smirnova
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou, 510650, People's Republic of China.
authors.forename: Yueming
authors.initials: Y
authors.lastname: Jiang
mesh_terms: D005638:Fruit / Q000378:metabolism*; D032125:Litchi / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D014867:Water / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D014867:Water
keywords: Cuticular waxes; Pericarp; Plant cuticle; Water loss kinetics; Water permeability; Water sorption