title: Chromium tolerance, oxidative stress response, morphological characteristics, and FTIR studies of phytopathogenic fungus Sclerotium rolfsii.
abstract: Sclerotium rolfsii is one of the most destructive fungal plant pathogens that can infect over 500 plants and can adapt to diverse environmental conditions. The present research work was carried out to evaluate the impact of both hexa- and trivalent chromium (Cr) on growth, morphology, enzymatic characteristics, and metal accumulation in S. rolfsii under laboratory conditions. Experiments were performed in both malt extract broth and agar growth medium amended with six different concentrations (10, 20, 40, 60, 80, and 100 ppm) of each Cr(III) and Cr(VI) ions inoculated with fungus and incubated for 6-7 days at 25 ± 3 °C. In broth medium, the total protein content was declined and activities of antioxidant enzymes were increased with an increase in metal concentrations. Lower concentrations (10 ppm) of the metal ions stimulated the growth of fungus and higher concentrations (60-100) inhibited it. The Fourier transform infrared spectroscopy (FTIR) assessment showed hydroxyl, carboxyl, and amine groups as major metal binding sites. In agar medium, tolerance index was decreased up to 0.56 at 10-80 ppm of Cr(III) and up to 0.62 at 10-60 ppm of Cr(VI). Considerable modifications were observed in hyphal and sclerotial morphology with an increase in concentration of metal ions. The current study concluded that interference of Cr with growth and physiological process of S. rolfsii could affect its infection level on its host plant. This study provides important information regarding cultivation of susceptible plant varieties in Cr-polluted soil as evidenced by pathogen growth up to 50 ppm of Cr(III) and Cr(VI) ions.
authors.affiliation: Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan.
authors.forename: Shahid
authors.initials: S
authors.lastname: Rafi
authors.affiliation: Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan. aamnaa29@yahoo.com.
authors.forename: Amna
authors.initials: A
authors.lastname: Shoaib
authors.affiliation: Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan.
authors.forename: Zoia Arshad
authors.initials: ZA
authors.lastname: Awan
authors.affiliation: Institute of Chemistry, University of the Punjab, Lahore, Pakistan.
authors.forename: Nayab Batool
authors.initials: NB
authors.lastname: Rizvi
authors.affiliation: Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan.
authors.lastname: Nafisa
authors.affiliation: Institute of Chemical Engineering & Technology, University of the Punjab, Lahore, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Shafiq
mesh_terms: D000975:Antioxidants / Q000032:analysis; D001487:Basidiomycota / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology*; D002857:Chromium / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D006131:Growth Inhibitors / Q000378:metabolism*; D006133:Growth Substances / Q000378:metabolism*; D025301:Hyphae / Q000166:cytology / Q000187:drug effects; D018384:Oxidative Stress; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D000975:Antioxidants; D003470:Culture Media; D006131:Growth Inhibitors; D006133:Growth Substances; D002857:Chromium