title: Cinnamic acid inhibits growth but stimulates production of pathogenesis factors by in vitro cultures of Fusarium oxysporum f.sp. niveum.
abstract: Long-term monoculture of watermelon leads to frequent occurrence of watermelon fusarium wilt caused by Fusarium oxysporum f.sp. niveum (FON). Some allelochemicals contained in watermelon root exudates and decaying residues are possibly responsible for promoting the wilt disease. The purpose of this study was to evaluate the allelopathic effect of artificially applied cinnamic acid on FON. Results demonstrated that hyphal growth of FON was strongly inhibited by cinnamic acid. At the highest concentration of cinnamic acid, the biomass in liquid culture was decreased by 63.3%, while colony diameter, conidial germination on plates, and conidial production in liquid culture were completely inhibited. However, mycotoxin production and activity of phytopathogenic enzymes were greatly stimulated. Mycotoxin yield, pectinase activity, proteinase activity, cellulase activity, and amylase activity were increased by 490, 590, 760, 2006, and 27.0%, respectively. It was concluded that cinnamic acid dramatically stimulated mycotoxin production and activities of hydrolytic enzymes by FON but inhibited growth and germination of FON. The findings presented here indicate that cinnamic acid is involved in promoting watermelon fusarium wilt.
authors.affiliation: College of Resources and Environmental Sciences, Nanjing Agricultural University, China.
authors.forename: Hong-Sheng
authors.initials: HS
authors.lastname: Wu
authors.forename: Waseem
authors.initials: W
authors.lastname: Raza
authors.forename: Jia-Qin
authors.initials: JQ
authors.lastname: Fan
authors.forename: Yong-Gang
authors.initials: YG
authors.lastname: Sun
authors.forename: Wei
authors.initials: W
authors.lastname: Bao
authors.forename: Qi-Rong
authors.initials: QR
authors.lastname: Shen
mesh_terms: D000681:Amylases / Q000378:metabolism; D018533:Biomass; D002480:Cellulase / Q000378:metabolism; D002934:Cinnamates / Q000494:pharmacology*; D029773:Citrullus / Q000382:microbiology*; D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D005670:Fusarium / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism / Q000472:pathogenicity*; D018525:Germination / Q000187:drug effects; D009183:Mycotoxins / Q000096:biosynthesis*; D010447:Peptide Hydrolases / Q000378:metabolism; D011096:Polygalacturonase / Q000378:metabolism; D013172:Spores, Fungal
chemical_list: D002934:Cinnamates; D009183:Mycotoxins; C029010:cinnamic acid; D000681:Amylases; D011096:Polygalacturonase; D002480:Cellulase; D010447:Peptide Hydrolases