In the last decades, the use of fungicides in agriculture for fungi diseases control has become crucial. Fungicide research has produced a diverse range of products with novel modes of action. However, the extensive use of these compounds in the agriculture system raises public concern because of the harmful potential of such substances in the environment and human health. Moreover, the phytotoxic effects of some fungicides are already recognized but little is known about the impact of these compounds on the photosynthetic apparatus. This paper presents a comprehensive overview of the literature considering different classes of fungicides and their effects on plant physiology, with particular emphasis on photosynthesis. 1. Introduction Fungicides are chemical compounds or biological organisms that destroy or inhibit the growth of fungi or fungal spores [1]. The use of fungicides for an effective control of plant diseases has become crucial in the last decades in the agriculture system since it is estimated that fungal infections cause yield reductions of almost 20% of crops worldwide [1]. Due to their relatively low cost, ease of use, and effectiveness, fungicides became the primary means of fungi control [2]. However, the extensive use of these compounds to control fungal disease in plants raises the appearance of new strains of pathogens that have become resistant to the available commercial products [3]. Fungicide toxicity is not always restricted to the target pest organism, having also been demonstrated in mammals [4] including humans [5]. The extensive use of fungicides in plant protection against fungal disease generates long-term residues in food and in the environment [6, 7]. In the annual EU report, EFSA (European Food Safety Authority), where vegetables and fruits of 27 countries were surveyed for pesticides contamination, the results highlighted that dithiocarbamates are among the most common residual contaminants. Thus, the abusive use of such compounds in agriculture has mobilized public concern because of the harmful potential of such substances in the environment and in the food chain representing a risk for human health [6]. Most of the work dealing with the impact of fungicides in agriculture is focused on their efficiency against fungal pathogens or their residues in crops [6, 8]. Several reports appoint that some fungicides may enhance plant defences through phytoalexin synthesis and cell wall lignification or stimulate enzymes involved in the synthesis of phenolic compounds [8–10]. Others describe the putative protective role of
References
[1]
M. L. Gullino, P. Leroux, and C. M. Smith, “Uses and challenges of novel compounds for plant disease control,” Crop Protection, vol. 19, no. 1, pp. 1–11, 2000.
[2]
X. J. Xia, Y. Y. Huang, L. Wang et al., “Pesticides-induced depression of photosynthesis was alleviated by 24-epibrassinolide pretreatment in Cucumis sativus L.,” Pesticide Biochemistry and Physiology, vol. 86, no. 1, pp. 42–48, 2006.
[3]
P. C. García, R. M. Rivero, J. M. Ruiz, and L. Romero, “The role of fungicides in the physiology of higher plants: implications for defense responses,” Botanical Review, vol. 69, no. 2, pp. 162–172, 2003.
[4]
F. Belpoggi, M. Soffritti, M. Guarino, L. Lambertini, D. Cevolani, and C. Maltoni, “Results of long-term experimental studies on the carcinogenicity of ethylenebis- dithiocarbamate (mancozeb) in rats,” Annual New York Academic Science, vol. 982, pp. 123–136, 2002.
[5]
C. A. C. Mendes, G. E. Mendes, J. P. Cipullo, and E. A. Burdmann, “Acute intoxication due to ingestion of vegetables contaminated with aldicarb,” Clinical Toxicology, vol. 43, no. 2, pp. 117–118, 2005.
[6]
European Food Safety Authority, “Annual report on pesticide residues,” EFSA Scientific Report vol. 305, 2009.
[7]
A. N. Petit, F. Fontaine, C. Clément, and N. Vaillant-Gaveau, “Photosynthesis limitations of grapevine after treatment with the fungicide fludioxonil,” Journal of Agricultural and Food Chemistry, vol. 56, no. 15, pp. 6761–6767, 2008.
[8]
G. Saladin, C. Magné, and C. Clément, “Effects of fludioxonil and pyrimethanil, two fungicides used against Botrytis cinerea, on carbohydrate physiology in Vitis vinifera L.,” Pest Management Science, vol. 59, no. 10, pp. 1083–1092, 2003.
[9]
J. P. Bryant, F. S. Chapin, and D. R. Klein, “Carbon/nutrient balance of boreal plants in relation to vertebrate herbivory,” Oikos, vol. 40, no. 3, pp. 357–368, 1983.
[10]
C. S. Awmack and S. R. Leather, “Host plant quality and fecundity in herbivorous insects,” Annual Review of Entomology, vol. 47, pp. 817–844, 2002.
[11]
Y. X. Wu and A. Von Tiedemann, “Impact of fungicides on active oxygen species and antioxidant enzymes in spring barley (Hordeum vulgare L.) exposed to ozone,” Environmental Pollution, vol. 116, no. 1, pp. 37–47, 2002.
[12]
M. Muthukumarasamy and R. Panneerselvam, “Amelioration of NaCl stress by triadimefon in peanut seedlings,” Plant Growth Regulation, vol. 22, no. 3, pp. 157–162, 1997.
[13]
A. M. Ahmed, M. D. Heikal, and O. S. Hindawy, “Side effects of benomyl (Fungicide) treatments on sunflower, cotton and cowpea plants,” Phyton, vol. 23, pp. 185–195, 1983.
[14]
R. Untiedt and M. Blanke, “Effects of fruit thinning agents on apple tree canopy photosynthesis and dark respiration,” Plant Growth Regulation, vol. 35, no. 1, pp. 1–9, 2001.
[15]
R. Untiedt and M. M. Blanke, “Effects of fungicide and insecticide mixtures on apple tree canopy photosynthesis, dark respiration and carbon economy,” Crop Protection, vol. 23, no. 10, pp. 1001–1006, 2004.
[16]
M. P. Yuste and J. Gostinear, Handbook of Agriculture, Marcel Dekker, New York, NY, USA, 1999.
[17]
M. Hunsche, L. Damerow, M. Schmitz-Eiberger, and G. Noga, “Mancozeb wash-off from apple seedlings by simulated rainfall as affected by drying time of fungicide deposit and rain characteristics,” Crop Protection, vol. 26, no. 5, pp. 768–774, 2007.
[18]
L. G. Copping, “Review of major agrochemical classes and uses,” in Chemistry and Technology of Agrochemical Foundations, D. A. Knowles, Ed., p. 29, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1998.
[19]
C. J. Delp, “Benzimidazole and related fungicides,” in Modem Selective Fungicides: Properties, Applications, Mechanisms of Action, H. Lyr, Ed., pp. 233–244, Wiley, New York, NY, USA, 1987.
[20]
C. Tomlin, “The pesticide manual: a world compendium,” in Incorporating the Agrochemicals Handbook, Royal Society of Chemistry, England, UK, 1994.
[21]
H. G. Hewitt, Fungicides in Crop Protection, CAB International, New York, NY, USA, 1998.
[22]
B. W. Krugh and D. Miles, “Monitoring the effects of five "nonherbicidal" pesticide chemicals on terrestrial plants using chlorophyll fluorescence,” Environmental Toxicology and Chemistry, vol. 15, no. 4, pp. 495–500, 1996.
[23]
M. W. Van Iersel and B. Bugbee, “Phytotoxic effects of benzimidazole fungicides on bedding plants,” Journal of the American Society for Horticultural Science, vol. 121, no. 6, pp. 1095–1102, 1996.
[24]
M. A. Nason, J. Farrar, and D. Bartlett, “Strobilurin fungicides induce changes in photosynthetic gas exchange that do not improve water use efficiency of plants grown under conditions of water stress,” Pest Management Science, vol. 63, no. 12, pp. 1191–1200, 2007.
[25]
J. Glaab and W. M. Kaiser, “Increased nitrate reductase activity in leaf tissue after application of the fungicide Kresoxim-methyl,” Planta, vol. 207, no. 3, pp. 442–448, 1999.
[26]
K. Grossmann, J. Kwiatkowski, and G. Caspar, “Regulation of phytohormone levels, leaf senescence and transpiration by the strobilurin kresoxim-methyl in wheat (Triticum aestivum),” Journal of Plant Physiology, vol. 154, no. 5-6, pp. 805–808, 1999.
[27]
K. P. Bader and R. Abdel-Basset, “Adaptation of plants to anthropogenic and environmental stresses,” in The Effects of Air Constituents and Plant-Protective Chemicals, M. Pessarakli, Ed., Handbook of Plant and Crop Stress, pp. 973–1010, Marcel Dekker, New York, NY, USA, 1999.
[28]
L. Mihuta-Grimm, W. A. Erb, and R. C. Rowe, “Fusarium crown and root rot of tomato in greenhouse rock wool systems: sources of inoculum and disease management with benomyl,” Plant Disease, vol. 74, pp. 996–1002, 1990.
[29]
H. K？hle, K. Grossmann, G. Retzlaff, and A. Akers, “Physiological effects of the new fungicide Juwel on yield in cereals,” Gesunde Pflanzen, vol. 49, no. 8, pp. 267–271, 1997.
