scholarly journals Developmental Regulation of Monoterpene Biosynthesis in the Glandular Trichomes of Peppermint

2000 ◽  
Vol 122 (1) ◽  
pp. 215-224 ◽  
Author(s):  
Marie E. McConkey ◽  
Jonathan Gershenzon ◽  
Rodney B. Croteau
Keyword(s):  
Developmental Regulation ◽  
Glandular Trichomes ◽  
Monoterpene Biosynthesis

scholarly journals Developmental regulation of lupulin gland-associated genes in aromatic and bitter hops (Humulus lupulus L.)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Josef Patzak ◽  
Alena Henychová ◽  
Jaroslav Matoušek
Keyword(s):  
Acid Content ◽  
Environmental Control ◽  
Developmental Regulation ◽  
Glandular Trichomes ◽  
Glandular Trichome ◽  
Humulus Lupulus ◽  
Acid Biosynthesis ◽  
Bitter Acids ◽  
Bitter Acid ◽  
Developmental Differentiation

Abstract Background Hop (Humulus lupulus L.) bitter acids are valuable metabolites for the brewing industry. They are biosynthesized and accumulate in glandular trichomes of the female inflorescence (hop cone). The content of alpha bitter acids, such as humulones, in hop cones can differentiate aromatic from bitter hop cultivars. These contents are subject to genetic and environmental control but significantly correlate with the number and size of glandular trichomes (lupulin glands). Results We evaluated the expression levels of 37 genes involved in bitter acid biosynthesis and morphological and developmental differentiation of glandular trichomes to identify key regulatory factors involved in bitter acid content differences. For bitter acid biosynthesis genes, upregulation of humulone synthase genes, which are important for the biosynthesis of alpha bitter acids in lupulin glands, could explain the higher accumulation of alpha bitter acids in bitter hops. Several transcription factors, including HlETC1, HlMYB61 and HlMYB5 from the MYB family, as well as HlGLABRA2, HlCYCB2–4, HlZFP8 and HlYABBY1, were also more highly expressed in the bitter hop cultivars; therefore, these factors may be important for the higher density of lupulin glands also seen in the bitter hop cultivars. Conclusions Gene expression analyses enabled us to investigate the differences between aromatic and bitter hops. This study confirmed that the bitter acid content in glandular trichomes (lupulin glands) is dependent on the last step of alpha bitter acid biosynthesis and glandular trichome density.

scholarly journals The mevalonate pathway contributes to monoterpene production in peppermint

2020 ◽  
Author(s):  
Somnath Koley ◽  
Eva Grafahrend-Belau ◽  
Manish L. Raorane ◽  
Björn H. Junker
Keyword(s):  
Metabolic Flux ◽  
Mevalonate Pathway ◽  
Glandular Trichomes ◽  
Quantitative Description ◽  
Pentose Phosphate ◽  
Mep Pathway ◽  
Flux Analysis ◽  
Mva Pathway ◽  
Isoprenoid Metabolism ◽  
Monoterpene Biosynthesis

ABSTRACTPeppermint produces monoterpenes which are of great commercial value in different traditional and modern pharmaceutical and cosmetic industries. In the classical view, monoterpenes are synthesized via the plastidic 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, while the cytosolic mevalonate (MVA) pathway produces sesquiterpenes. Interactions between both pathways have been documented in several other plant species, however, a quantitative understanding of the metabolic network involved in monoterpene biosynthesis is still lacking. Isotopic tracer analysis, steady state 13C metabolic flux analysis (MFA) and pathway inhibition studies were applied in this study to quantify metabolic fluxes of primary and isoprenoid metabolism of peppermint glandular trichomes (GT). Our results offer new insights into peppermint GT metabolism by confirming and quantifying the crosstalk between the two isoprenoid pathways towards monoterpene biosynthesis. In addition, a quantitative description of precursor pathways involved in isoprenoid metabolism is given. While glycolysis was shown to provide precursors for the MVA pathway, the oxidative bypass of glycolysis fueled the MEP pathway, indicating prominent roles for the oxidative branch of the pentose phosphate pathway and RuBisCO. This study reveals the potential of 13C-MFA to ascertain previously unquantified metabolic routes of the trichomes and thus advancing insights on metabolic engineering of this organ.

An investigation into the ultrastructure and histochemistry of glandular trichomes of johnsongrass [Sorghum halepense (L.) Pers.] leaves

1992 ◽  
Vol 50 (1) ◽  
pp. 842-843 ◽  
Author(s):  
R. N. Paul ◽  
C. G. McWhorter ◽  
J.C. Ouzts
Keyword(s):  
Glandular Trichomes ◽  
Sorghum Halepense ◽  
Secretory Apparatus

Secretory trichomes have been described on johnsongrass leaves previously, but there is little knowledge of their ultrastructure or the nature of their secretion. Since johnsongrass is a pernicious weed, there is much interest in the nature of compounds found on its foliar surface, and the possible effect of these extrusions on herbicide efficiency. This report describes the results of an investigation into the ultrastructure of the secretory apparatus, and into the nature of the secretion.

Hop pellets type 90: ESEM studies of glandular trichomes morphological and structural changes during the different phases of hop processing

2011 ◽  
Vol 40 (2) ◽  
pp. 282-290 ◽  
Author(s):  
S. Srečec ◽  
V. Zechner-Krpan ◽  
S. Marag ◽  
G. Mršić ◽  
I. Špoljarić
Keyword(s):  
Structural Changes ◽  
Glandular Trichomes
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