Roots of the Invasive Species Carduus nutans L. and C. acanthoides L. Produce Large Amounts of Aplotaxene, a Possible Allelochemical
- 543 Downloads
The invasive thistle Carduus nutans has been reported to be allelopathic, yet no allelochemicals have been identified from the species. In a search for allelochemicals from C. nutans and the closely related invasive species C. acanthoides, bioassay-guided fractionation of roots and leaves of each species were conducted. Only dichloromethane extracts of the roots of both species contained a phytotoxin (aplotaxene, (Z,Z,Z)-heptadeca-1,8,11,14-tetraene) with sufficient total activity to potentially act as an allelochemical. Aplotaxene made up 0.44 % of the weight of greenhouse-grown C. acanthoides roots (ca. 20 mM in the plant) and was not found in leaves of either species. It inhibited growth of lettuce 50 % (I 50) in soil at a concentration of ca. 0.5 mg g−1 of dry soil (ca. 6.5 mM in soil moisture). These values gave a total activity in soil value (molar concentration in the plant divided by the molarity required for 50 % growth inhibition in soil = 3.08) similar to those of some established allelochemicals. The aplotaxene I 50 for duckweed (Lemna paucicostata) in nutrient solution was less than 0.333 mM, and the compound caused cellular leakage of cucumber cotyledon discs in darkness and light at similar concentrations. Soil in which C. acanthoides had grown contained aplotaxene at a lower concentration than necessary for biological activity in our short-term soil bioassays, but these levels might have activity over longer periods of time and might be an underestimate of concentrations in undisturbed and/or rhizosphere soil.
KeywordsAllelochemical Allelopathy Aplotaxene Carduus nutans Carduus acanthoides Phytotoxin
We thank Robert Johnson, Solomon Green III, Joe Keller, and Britta Teller for technical assistance and Dr. Martin Locke for providing soils.
- Abdallah OM, Ramadan MA, El-Shanawany MA (1989) Phytochemical study of Carduus nutans L. (Asteraceae). Bull Fac Sci Assiut Univ 18:69–76Google Scholar
- Duke SO (2010) Allelopathy: current status of research and future of the discipline: a commentary. Allelopathy J 25:17–30Google Scholar
- Hiradate S (2006) Isolation strategies for finding bioactive compounds: specific activity vs. total activity. Am Chem Soc Symp Ser 927:113–126Google Scholar
- Kaloshina NA, Mazulin AV (1988) Flavonoids of Carduus nutans. Khim Prir Soedin 3:453Google Scholar
- Khan AL, Hussain J, Hamayun M, Shinwari ZK, Khan H, Kang Y-H, Kang S-M, Lee I-J (2009) Inorganic profile and allelopathic effect of endemic Inula koelzii from Himalaya Pakistan. Pak J Bot 41:2517–2527Google Scholar
- Mulligan GA, Moore RJ (1961) Natural selection among hybrids between Carduus acanthoides and C. nutans in Ontario. Can J Bot 39:421–430Google Scholar
- Naves YR (1949) Costus oil. Manuf Chem 20:318–320Google Scholar
- Nazaruk J, Karna E, Kelemba D (2012) The chemical composition of the essential oils of Cirsium palustre and C. rivulare and their antiproliferative effect. Nat Prod Comm 7:269–272Google Scholar
- Soil Survey Staff (2010) Keys to soil taxonomy, 11th edn. USDA-Natural Resources Conservation Service, Washington, DCGoogle Scholar
- Takano S, Kawaminami S (1988) Cyperenyl acetate and cyperenal from Cirsium dipscolepis. Phytochemistry 29:197–1199Google Scholar
- Tesevic V, Djokovic D, Vajs V, Marin P, Milosavljevic S (1994) Constituents of the roots of plant species Centauria scabiosa. J Serb Chem Soc 59:979–981Google Scholar