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Assessment of Humulus lupulus' essential oil profile and its effect on fungal infection
Author(s) -
Walden Sean D.,
Anderson C. William,
Lowry Edward,
Wolyniak Michael J.
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.656.5
Subject(s) - humulus lupulus , hop (telecommunications) , powdery mildew , biology , essential oil , botany , horticulture , food science , computer network , pepper , computer science
Humulus lupulus , commonly known as the common hop, is a lucrative cash crop grown in large quantities across Europe and the northwest region of the United States. The mature female flowers, or cones, of H. lupulus produce a yellow, sappy substance as a defense mechanism against insect herbivory. This substance, commonly known as lupulin, contains a collection of essential oils that have signature strong flavors and aromatic qualities that give hops their commercial value in brewing. Beer and mead, the products of hops‐mediated brewing, obtain their unique flavors through the different combinations of oils produced by different varieties of H. lupulus . While the anti‐herbivory properties of H. lupulus essential oils are well‐established, relatively less is known about their role in suppressing the growth of pathogenic fungi. Indeed, H. lupulus populations have been plagued by Downy Mildew ( Pseudoperonospora humuli ) and Powdery Mildew ( Podosphaera macularis ). These pathogens can infect entire commercial crops in a short amount of time and can cost commercial producers a significant amount of money if crops become significantly infected. Coincidentally, the climate which favors growth of P. humuli and P. macularis is also the climate in which H. lupulus grow best. This fact underscores the importance of better understanding how to control the growth of these fungi with respect to the future of H. lupulus agriculture. In a recent study, essential oils from thyme ( Thymus vulgaris L. ) have been shown to have anti‐fungal qualities (Zambonelli 1996). Thus, the essential oils produced by H. lupulus could similarly be effective in preventing infection by these pathogens. With the goal of better understanding the role of essential oils and their distinct profiles in the many varieties of H. lupulus , five common varieties were profiled using Gas Chromatography‐Mass Spectroscopy (GC‐MS). This technique provides a holistic look at the different oils produced in different varieties of H. lupulus . Preliminary work has suggested that the most prominent essential oils present in all tested varieties includes humulene, beta‐myrcene, beta‐caryophyllene, and lupulon. Beta‐caryophyllene is especially interesting in these results based on its previously determined role as an anti‐fungal agent. Humulene is also interesting due to it being an isomer of beta‐caryophyllene. There are some less abundant oils in the profiles that are unique to distinct varieties and which are currently being analyzed through a measure of zone of inhibition following inoculation with individual essential oils on impregnated disks exposed to fungal cultures on potato dextrose agar (PDA) medium. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .