Fast Phenotyping of LFS-Silenced (Tearless) Onions by Desorption Electrospray Ionization Mass Spectrometry (DESI-MS)

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• 作者：Nigel I. Joyce ; Colin C. Eady ; Patrick Silcock ; Nigel B. Perry ; John W. van Klink
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2013
• 出版时间：February 20, 2013
• 年：2013
• 卷：61
• 期：7
• 页码：1449-1456
• 全文大小：396K
• 年卷期：v.61,no.7(February 20, 2013)
• ISSN：1520-5118

文摘

Fast MS techniques have been applied to the analysis of sulfur volatiles in Allium species and varieties to distinguish phenotypes. Headspace sampling by proton transfer reaction (PTR) MS and surface sampling by desorption electrospray ionization (DESI) MS were used to distinguish lachrymatory factor synthase (LFS)-silenced (tearless; LFS鈭? onions from normal, LFS-active (tear-inducing; LFS+), onions. PTR-MS showed lower concentrations of the lachrymatory factor (LF, 3) and dipropyl disulfide 12 from tearless onions. DESI-MS of the tearless onions confirmed the decreased LF 3 and revealed much higher concentrations of the sulfenic acid condensates. Using DESI-MS with MS² could distinguish zwiebelane ions from thiosulfinate ions. DESI-MS gave reliable fast phenotyping of LFS+ versus LFS鈥?onions by simply scratching leaves and recording the extractable ions for <0.5 min. DESI-MS leaf compound profiles also allowed the rapid distinction of a variety of Allium cultivars to aid plant breeding selections.

Keywords:

Allium cepa; tearless onions; desorption electrospray ionization (DESI); proton transfer reaction (PTR); mass spectrometry; phenotyping; breeding; lachrymatory factor; zwiebelane; disulfide; thiosulfinates; 2,3-dimethyl-1,4-butanedithial S-oxide