Abstract
Extracts ofCitrus jambhiri foliage exposed to and shielded from UV-B radiation were assayed for phytochemical changes and phototoxicity against four fungal pathogens, two of which (Fusarium solani andF. oxysporum) are causative agents of root rots and two of which (Penicillium italicum andP. digitatum) are associated with fruit rots. Conidial pigment mutants of these four fungal species were assayed to determine whether pigments play a role in protecting fungi against plant photosensitizers. Exposure to 10.2 kJ/ day UV-B radiation for 95 days significantly reduced phototoxicity of leaf extracts to fungi. Although furanocoumarin levels were reduced by UV-B, analysis of covariance revealed that variation in phototoxicity of the extracts cannot be attributed entirely to variation in furanocoumarin content; thus, the possibility exists that nonfuranocoumarin phototoxic constituents, as yet unidentified, respond to UV-B exposure and contribute to overall phototoxic defense ofC. jambhiri against pathogens. Root rot fungi were substantially more sensitive to furanocoumarin phototoxicity than were fruit rot fungi, a pattern consistent with the amount of light exposure normally experienced by these fungi when associated with phototoxic plants. Although pigmented strains of all four species displayed greater resistance to phototoxicity of pure furanocoumarins, no strain differences were detected in assays of foliar extracts; this finding also suggests that nonfuranocoumarin constituents may be involved in the phototoxic defense ofC. jambhiri against pathogens.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Asthana, A., Larson, R.A., Marley, K.A., andTuveson, R.W. 1992. Mechanisms of citral phototoxicity.Photochem. Photobiol. 56(2):211–222.
Asthana, A., andTuveson, R.W. 1992. Effects of UV and phototoxins on selected fungal pathogens ofCitrus jambhiri.Int. J. Plant Sci. 153(3):442–452.
Berenbaum, M.R., andNeal, J.J. 1985. Synergism between myristicin and xanthotoxin, anaturally co-occurring plant toxicant.J. Chem. Ecol. 11:1349–1358.
Caldwell, M.M. 1981. Plant responses to solar ultraviolet radiation, pp. 167–169,in Encyclopedia of Plant Physiology Vol. 12a, (O.L. Lange, P.S. Nobel, C.B. Osmond, and H. Ziegler, eds.), Physiological Plant Ecology I. Springer-Verlag, Berlin.
Carns, H.R., Graham, J.H., andRavitz, S.J. 1978. Effects of UV-B radiation on selected leaf pathogenic fungi and on disease severity. SEA, AR Final BACER Report submitted to the Environmental Protection Agency. EPA-IAG-D6-0168. United States Department of Agriculture, Washington, D.C.
Desjardins, A.E., Spencer, G.F., andPlattner, R.D. 1989. Tolerance metabolism of furanocoumarins by the phytopathogenic fungusGibberella pulicaris (Fusarium sambucinum).Phytochemistry 28:2963–2969.
Downum, K.R., Hancock, W.E., andTowers, G.H.N. 1982. Mode of action ofα-terthienyl onEscherichia coli: Evidence for a photodynamic effect on membranes.Photochem. Photobiol. 36:517–523.
Fisher, J.R., andTrama, L.A. 1979. High performance liquid Chromatographic determination of some coumarins and psoralens found in citrus peel oils.Agric. Food. Chem. 27:1334–1337.
Hader, D.P., andTevini, M. 1987. Excited states and their relaxation,in General Photobiology. Pergamon Press, New York.
Israel, E. 1985. Outbreak of phototoxic dermatitis from limes-Maryland.Morbid. Mort. Rep. 34:462–463.
Joshi, P.C., andPathak, M.A. 1983. Production of singlet oxygen and Superoxide by psoralens and their biological significance.Biochem. Biophys. Res. Commun. 112:638–646.
Karlberg, A.T., Boman, A., andMelin, B. 1991. Animal experiments on the allergenicity of d-limonene-the citrus solvent.Ann. Occup. Hyg. 35:419–426.
Kato, T., Rothman, R.H., andClark, A.J. 1977. Analysis of the role of recombination and repair in mutagenesis ofEscherichia coli by UV irradiation.Genetics 87:1–18.
Leonardo, J.M., Reynolds, P.R., andTuveson, R.W. 1984. Mutation induction by 365-nm radiation and far-ultraviolet light inEscherichia coli strains differing in near- and far-ultraviolet light sensitivity.Mutat. Res. 126:1–8.
Martin, J.T., Baker, E.A., andByrde, R.J.W. 1966. The fungitoxicities of cuticular and cellular components of citrus lime leaves.Ann. Appl. Biol. 57:491–500.
McCloud, E.S., andBerenbaum, M.R. 1994. Stratospheric ozone depletion and plant-insect interactions: Effects of UV-B radiation on foliage quality ofCitrus jambhiri forTrichoplusia ori. J. Chem. Ecol. In press.
McCloud, E.S., Berenbaum, M.R., andTuveson, R.W. 1992. Furanocoumarin content and phototoxicity of rough lemon (Citrus jambhiri) foliage exposed to enhanced ultraviolet-B (UV-B) irradiation.J. Chem. Ecol. 18:1125–1137.
Mirecki, R.M., andTeramura, A.H. 1984. Effects of ultraviolet-B irradiance on soybeans V. The dependence of plant sensitivity on photosynthetic flux density during and after leaf expansion.Plant Physiol. 74:475–480.
Murray, R.D.H., Mendez, J., andBrown, S.A. 1982. The Natural Coumarins. John Wiley & Sons, New York.
Pfyffer, G.E., Panfil, I., andTowers, G.H.N. 1982. Monofunctional covalent photobinding of dictamine, a furoquinoline alkaloid, to DNA as target in vitro.Photochem. Photobiol. 35:63–68.
Sokal, R.R., andRohlf, F.J. 1982. Biometry, 2nd ed. W.H. Freeman, New York.
Song, P. 1982. Photoreactive states of furocoumarins. Presented at the Conference on Photobiologic, Toxicologic, and Pharmacologic Aspects of Psoralens. Research Triangle Park, North Carolina. March 1–3.
Tevini, M., Iwanzik, W., andTeramura, A.H. 1983. Effects of UV-B radiation on plants during mild water stress. II. Effects on growth, protein and flavonoid content.Z. Pflanzenphysiol. 110:459–467.
Towers, G.H.N., Graham, E.A., Spenser, I.D., andAbramowski, Z. 1981. Phototoxic furanoquinolines of the Rutaceae.Planta Med. 41:136–142.
Tuveson, R.W. 1987. Using bacterial mutants and transforming DNA to define phototoxic mechanisms,in J.R. Heitz and K.R. Downum, eds. Light-Activated Pesticides. American Chemical Society Symposium 339, pp. 192–205, Washington, D.C.
Tuveson, R.W., Berenbaum, M.R., andHeininger, E.E. 1986. Inactivation and mutagenesis by phototoxins usingEscherichia coli strains differing in sensitivity to near-and-far ultraviolet light.J. Chem. Ecol. 12:933–948.
Tuveson, R.W., Larson, R.A., andKagan, J. 1988. The role of cloned carotenoid genes expressed inEscherichia coli in protecting against inactivation by far-UV, near-UV, and specific phototoxic molecules.J. Bacteriol. 171:4675–4680.
von Sonntag, C. 1987. The Chemical Basis of Radiation Biology. Taylor and Francis, Philadelphia.
Whiteside, J.O., Garnsey, S.M., andTimmer, L.W., eds. 1988. Compendium of Citrus Diseases. St. Paul: American Phytopathology Society.
Zobel, A.M., andBrown, S.A. 1988. Determination of furanocoumarins on the leaf surface ofRuta graveolens with an improved extraction technique.J. Nat. Prod. 51:941–946.
Zobel, A.M., andBrown, S.A. 1989. Histological localization of furanocoumarin inRuta graveolens shoots.Can. J. Bot. 67:915–921.
Zobel, A.M., andBrown, S.A. 1990a. Dermatitis-inducing furanocoumarins on leaf surfaces of eight species of rutaceous and umbelliferous plants.J. Chem. Ecol. 16:693–700.
Zobel, A.M., andBrown, S.A. 1990b. Seasonal change of furanocoumarins in leaves inHeracleum lanatum.J. Chem. Ecol. 16:1623–1634.
Author information
Authors and Affiliations
Additional information
Deceased.
Rights and permissions
About this article
Cite this article
Asthana, A., McCloud, E.S., Berenbaum, M.R. et al. Phototoxicity ofCitrus jambhiri to fungi under enhanced UV-B radiation: Role of furanocoumarins. J Chem Ecol 19, 2813–2830 (1993). https://doi.org/10.1007/BF00980585
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00980585