Pyrenophoric acid, a phytotoxic sesquiterpenoid penta-2,4-dienoic acid produced by a potential mycoherbicide, Pyrenophora semeniperda.
نویسندگان
چکیده
A new phytotoxic sesquiterpenoid penta-2,4-dienoic acid, named pyrenophoric acid, was isolated from solid wheat seed culture of Pyrenophora semeniperda, a fungal pathogen proposed as a mycoherbicide for biocontrol of cheatgrass (Bromus tectorum) and other annual bromes. These bromes are serious weeds in winter cereals and also on temperate semiarid rangelands. Pyrenophoric acid was characterized as (2Z,4E)-5-[(7S,9S,10R,12R)-3,4-dihydroxy-2,2,6-trimethylcyclohexyl)]-3-methylpenta-2,4-dienoic acid by spectroscopic and chemical methods. The relative stereochemistry of pyrenophoric acid was assigned using 1H,1H couplings and NOESY experiments, while its absolute configuration was determined by applying the advanced Mosher's method. Pyrenophoric acid is structurally quite closely related to the plant growth regulator abscisic acid. When bioassayed in a cheatgrass coleoptile elongation test at 10(-3) M, pyrenophoric acid showed strong phytotoxicity, reducing coleoptile elongation by 51% relative to the control. In a mixture at 10(-4) M, its negative effect on coleoptile elongation was additive with that of cytochalasin B, another phytotoxic compound found in the wheat seed culture extract of this fungus, demonstrating that the extract toxicity observed in earlier studies was due to the combined action of multiple phytotoxic compounds.
منابع مشابه
Pyrenophoric acids B and C, two new phytotoxic sesquiterpenoids produced by Pyrenophora semeniperda.
Two new phytotoxic sesquiterpenoid acids, named pyrenophoric acids B and C, were isolated together with the related pyrenophoric and abscisic acids from solid Bromus tectorum (cheatgrass) seed culture of the seed pathogen Pyrenophora semeniperda. This fungus has been proposed as a mycoherbicide for biocontrol of cheatgrass (Bromus tectorum), a Eurasian annual grass that has become invasive in r...
متن کاملEnvironmental factors influencing Pyrenophora semeniperda-caused seed mortality in Bromus tectorum
Temperature and water potential strongly influence seed dormancy status and germination of Bromus tectorum. As seeds of this plant can be killed by the ascomycete fungus Pyrenophora semeniperda, this study was conducted to learn how water potential and temperature influence mortality levels in this pathosystem. Separate experiments were conducted to determine: (1) if P. semeniperda can kill dor...
متن کاملThe Grass Seed Pathogen Pyrenophora Semeniperda as a Biocontrol Agent for Annual Brome Grasses
Pyrenophora semeniperda’s current reported distribution worldwide is mainly temperate grasslands and winter cereal growing regions. Previous reports in Europe and Asia were not known, and strong doubt has been expressed that it occurs in the Old World. However, it has been discovered in Turkey and Greece. Using Internal Transcribed Spacer (ITS) for genetic identification, P. semeniperda’s exist...
متن کاملA spectroscopic study of the cis/trans-isomers of penta-2,4-dienoic acid attached to gold nanoclusters.
In this theoretical work, we present a spectroscopic analysis of the cis/trans-isomers of a molecular switch, penta-2,4-dienoic acid, attached to gold clusters of different size (1, 2 and 20 gold atoms). We have simulated 4 different spectroscopic techniques: Infrared spectroscopy, normal Raman scattering, absorption spectra and resonance Raman scattering. We discuss how the position and the co...
متن کاملExposure to Low Water Potentials and Seed Dormancy Favour the Fungus in the Pyrenophora semeniperda-Bromus tectorum Pathosystem
Finch H., Allen P., Meyer S. (2013): Exposure to low water potentials and seed dormancy favour the fungus in the Pyrenophora semeniperda–Bromus tectorum pathosystem. Plant Protect. Sci., 49 (Special Issue): S15–S20. In semi-arid regions of the United States, Pyrenophora semeniperda kills seeds of the winter annual Bromus tectorum. We report on pathosystem outcomes under manipulated water potent...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of natural products
دوره 77 4 شماره
صفحات -
تاریخ انتشار 2014