title: Diel rhythms in the volatile emission of apple and grape foliage.
abstract: This study investigated the diel emission of volatile organic compounds (VOCs) from intact apple (Malus x domestica Borkh., cv. Golden Delicious) and grape (Vitis vinifera L., cv. Pinot Noir) foliage. Volatiles were monitored continuously for 48 h by proton transfer reaction - time of flight - mass spectrometry (PTR-ToF-MS). In addition, volatiles were collected by closed-loop-stripping-analysis (CLSA) and characterized by gas chromatography-mass spectrometry (GC-MS) after 1 h and again 24 and 48 h later. Fourteen and ten volatiles were characterized by GC-MS in apple and grape, respectively. The majority of these were terpenes, followed by green leaf volatiles, and aromatic compounds. The PTR-ToF-MS identified 10 additional compounds and established their diel emission rhythms. The most abundant volatiles displaying a diel rhythm included methanol and dimethyl sulfide in both plants, acetone in grape, and mono-, homo- and sesquiterpenes in apple. The majority of volatiles were released from both plants during the photophase; whereas methanol, CO2, methyl-butenol and benzeneacetaldehyde were released at significantly higher levels during the scotophase. Acetaldehyde, ethanol, and some green leaf volatiles showed distinct emission bursts in both plants following the daily light switch-off. These new results obtained with a combined analytical approach broaden our understanding of the rhythms of constitutive volatile release from two important horticultural crops. In particular, diel emission of sulfur and nitrogen-containing volatiles are reported here for the first time in these two crops.
authors.affiliation: Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 5, 39100 Bolzano, Italy.
authors.forename: Valentino
authors.initials: V
authors.lastname: Giacomuzzi
authors.affiliation: Research and Innovation Centre, Fondazione Edmund Mach (FEM), Via E. Mach 1, 38010 San Michele all'Adige, Italy; School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, 02138 Cambridge, Massachusetts, USA.
authors.forename: Luca
authors.initials: L
authors.lastname: Cappellin
authors.affiliation: Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 5, 39100 Bolzano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Nones
authors.affiliation: Research and Innovation Centre, Fondazione Edmund Mach (FEM), Via E. Mach 1, 38010 San Michele all'Adige, Italy.
authors.forename: Iuliia
authors.initials: I
authors.lastname: Khomenko
authors.affiliation: Research and Innovation Centre, Fondazione Edmund Mach (FEM), Via E. Mach 1, 38010 San Michele all'Adige, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Biasioli
authors.affiliation: USDA, Agricultural Research Service, 5230 Konnowac Pass Rd, 98951 Wapato, Washington, USA.
authors.forename: Alan L
authors.initials: AL
authors.lastname: Knight
authors.affiliation: Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 5, 39100 Bolzano, Italy. Electronic address: sergio.angeli@unibz.it.
authors.forename: Sergio
authors.initials: S
authors.lastname: Angeli
mesh_terms: D002940:Circadian Rhythm; D008401:Gas Chromatography-Mass Spectrometry; D027845:Malus / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D013729:Terpenes / Q000032:analysis; D027843:Vitis / Q000737:chemistry*; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D013729:Terpenes; D055549:Volatile Organic Compounds
keywords: (E)-4,8-dimethyl-1,3,7-nonatriene (PubChem CID: 6449967); (E)-β-ocimene (PubChem CID: 5281553); (E,E)-α-farnesene; (E,E)-α-farnesene (PubChem CID: 5281516); (Z)-3-hexenol (PubChem CID: 5281167); (Z)-3-hexenyl acetate; (Z)-3-hexenyl acetate (PubChem CID: 5363388); Acetaldehyde; Acetaldehyde (PubChem CID: 177); CLSA-GC-MS; Constitutive volatiles; Linalool (PubChem CID: 6549); Malus x domestica, Rosaceae; Methanol; Methanol (PubChem CID: 887); PTR-ToF-MS; Vitis vinifera, Vitaceae; β-caryophyllene (PubChem CID: 5281515)