Leaf cuticular waxes of wild-type Welsh onion (Allium fistulosum L.) and a wax-deficient mutant: Compounds with terminal and mid-chain functionalities

Jedrzej Gozdzik, Lucas Busta, Reinhard Jetter

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Plant cuticles cover aerial organs to limit non-stomatal water loss and protect against insects and pathogens. Cuticles contain complex mixtures of fatty acid-derived waxes, with various chain lengths and diverse functional groups. To further our understanding of the chemical diversity and biosynthesis of these compounds, this study investigated leaf cuticular waxes of Welsh onion (Allium fistulosum L.) wild type and a wax-deficient mutant. Leaf waxes were extracted with chloroform, separated using thin layer chromatography (TLC), and analyzed using gas chromatography-mass spectrometry (GC-MS). The extracts contained typical wax compound classes found in nearly all plant lineages but also two uncommon compound classes. Analyses of characteristic MS fragmentation patterns followed by comparisons with synthetic standards identified the latter as very-long-chain ketones and primary ketols. The ketols were minor compounds, with chain lengths ranging from C28 to C32 and carbonyls mainly on C-18 and C-20 in wild type wax, and a C28 chain with C-16 carbonyl in the mutant. The ketones made up 70% of total wax in the wild type, consisting mainly of C31 isomers with carbonyl group on C-14 or C-16. In contrast, the mutant wax comprised only 4% ketones, with chain lengths C27 and C29 and carbonyls predominantly on C-12 and C-14, respectively. A two-carbon homolog shift between wild type and mutant was also observed in the primary alcohols (a major wax compound class), whilst alkanes exhibited a four-carbon shift. Overall, the compositional data shed light on possible biosynthetic pathways to wax ketones that can be tested in future studies.

Original languageEnglish (US)
Article number107679
JournalPlant Physiology and Biochemistry
Volume198
DOIs
StatePublished - May 2023

Bibliographical note

Funding Information:
The authors declare no competing interests.The authors wish to acknowledge Samantha Link for her invaluable help with Allium cultivation, as well as Liuyi Yang, Qianchun Li,u Yongqin Wang, and Lecheng Liu of the College of Horticulture and Gardening (Yangtze University) in the Beijing Vegetable Research Center (Beijing Academy of Agriculture and Forestry Sciences/Key Laboratory of Biology and Genetic Improvement of Horticultural Crops) for providing Allium germplasm. L.B wishes to acknowledge support in the form of a fellowship from the NSF Plant Genome Research Program (NSF PRFB IOS-1812037) as well as startup funds from the University of Minnesota Duluth Swenson College of Science and Engineering. R.J. gratefully acknowledges support by the Natural Sciences and Engineering Research Council (Canada) Discovery Grants Program (grant #262461).

Funding Information:
The authors wish to acknowledge Samantha Link for her invaluable help with Allium cultivation, as well as Liuyi Yang, Qianchun Li,u Yongqin Wang, and Lecheng Liu of the College of Horticulture and Gardening (Yangtze University) in the Beijing Vegetable Research Center (Beijing Academy of Agriculture and Forestry Sciences/Key Laboratory of Biology and Genetic Improvement of Horticultural Crops) for providing Allium germplasm. L.B wishes to acknowledge support in the form of a fellowship from the NSF Plant Genome Research Program (NSF PRFB IOS-1812037) as well as startup funds from the University of Minnesota Duluth Swenson College of Science and Engineering . R.J. gratefully acknowledges support by the Natural Sciences and Engineering Research Council (Canada) Discovery Grants Program (grant #262461 ).

Publisher Copyright:
© 2023 Elsevier Masson SAS

Keywords

  • Allium fistulosum
  • Cuticular wax
  • Isomers
  • Ketol
  • Ketone
  • Welsh onion

PubMed: MeSH publication types

  • Journal Article

Fingerprint

Dive into the research topics of 'Leaf cuticular waxes of wild-type Welsh onion (Allium fistulosum L.) and a wax-deficient mutant: Compounds with terminal and mid-chain functionalities'. Together they form a unique fingerprint.

Cite this