Physiological drought alters nepetalactone metabolisam in Nepeta rtanjensis leaves
2018
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Authors:
Aničić, NedaNestorović Živković, Jasmina
Matekalo, Dragana
Skorić, Marijana
Božunović, Jelena
Milutinović, Milica
Mišić, Danijela
Contributors
Uzelac, BrankaDocument Type:
Conference object (Published version)
,
© 2018 by the Serbian Plant Physiology Society
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Show full item recordAbstract:
Major constituents of Nepeta rtanjensis Diklić & Milojević: trans,cis-nepetalactone and its dehydrogenation
product dehydronepetalactone, are synthetized and accumulated in glandular
trichomes. Interestingly, dehydronepetalactone is the major monoterpenoid in fresh leaves of N.
rtanjensis, while the amount of this compound dramatically decreases in dry leaves. Furthermore,
dehydronepetalactone has been previously identified in Nepeta species mainly in the cases when
essential oils and extracts prepared from fresh plant material were analysed. All this lead us to presume
that nepetalactone metabolism is reprogrammed during the process of leaf dehydration.
Here we present for the first time an insight into the molecular background of constitutive nepetalactone
biosynthesis in leaves of N. rtanjensis and its alterations under physiological drought stress,
which was experimentally induced in vitro by exposing plants to PEG 8000 (3 MPa) for 1, 3 and 6
days. Leaves of PEG-treated and of non-treated plants were collected and subjected to gene expression
analysis and to metabolic profiling. Putative genes encoding enzymes for intermediate
steps of nepetalactone biosynthetic pathway (GPPS, GES, G8O, 8HGO, IS1 and IS2) were mined from
N. rtanjensis leaf transcriptome. Although majority of analysed genes were significantly down-regulated
during the process of leaf dehydration, PEG-induced physiological drought induced no
significant changes in nepetalactone content, while dehydronepetalactone content was slightly
decreased. The possible key enzymes controlling the nepetalactone biosynthetic-flux could be
GPPS, G8O, and IS1, which showed stable expression levels during dehydration. Stressed plants most likely maintain nepetalactone content stable by lowering both its biosynthesis and degradation,
which results in decreased dehydronepetalactone content in leaves, and thus in altered
nepetalactone/dehydronepetalactone ratio.
Keywords:
Nepetalactone; Dehydronepetalactone; Nepetalactone biosynthetic pathway genes; Physiological droughtFunding / projects:
- Physiological, chemical and molecular analysis of the diversity of selected rare and endangered plant species and application of biotechnology for ex situ conservation and production of biologically active compounds (RS-MESTD-Basic Research (BR or ON)-173024)
In:
- Uzelac B, editor. Book of abstracts. 3rd International Conference on Plant Biology (22nd SPPS Meeting); 2018 Jun 9-12; Belgrade, Serbia. Belgrade: Serbian Plant Physiology Society; Institute for Biological Research "Siniša Stanković"; Faculty of Biology; 2018. p. 121-2.