Chitosan effects on blackmold rot and pathogenic factors produced by Alternaria alternata in postharvest tomatoes.
By M. Reddy, P. Angers, F. Castaigne, J. Arul. 2000
87 citations recorded by the source corpus.
Stem scar application of chitosan inhibited growth and production of pathogenic factors by blackmold rot (Alternaria alternata (Fr.:Fr.) Keissl.) in challenged tomato (Lycopersicon esculentum Mill.) fruit stored at 20 °C for 28 days. Blackmold lesions were visible within 4 days of inoculation in control fruit, compared with >7 days in chitosan- treated fruit. Macerating enzyme activity (polygalacturonase, pectate lyase, and cellulase) in the tissue in the vicinity of the lesions was <50% in chitosan-treated fruit compared with control fruit. Chitosan also inhibited production of oxalic and fumaric acids (chelating agents) and host-specific toxins such as alternariol and alternariol monomethylether by the fungus. The pH of the infected tissue decreased from 4.7 to 4.0 in the control fruit, the optimum for polygalacturonase activity, while the pH of chitosan-treated fruit remained at 4.6. In addition, chitosan also induced production of rishitin (a phytoalexin) in tomato tissue. Such chitosan-pathogen-host interactions may be exploited in the control of postharvest pathogens of fresh fruit and vegetables. strict control due to potential health risks, and none of them are approved for postharvest use. Hence, there is a need to exploit natural antifungal substances and host defenses for the control of postharvest pathogens. Chitosan (s,1-4, linked glucosamine polymer), the deacetylated form of chitin, has been shown to be antifungal against a wide range of fungi (El Ghaouth et al., 1992a). Chitosan induces chitinases in plant tissue (El Ghaouth et al., 1992b; Mauch et al., 1984), structural defense barriers in bell pepper fruit ( Capsicum annuum L. var. annuum (Grossum Group)) (El Ghaouth et al., 1994), and elicits the production of phytoalexin in pea pods (Pisum sativum L.) (Kendra and Hadwiger, 1984). Chitosan coating of strawberries (Fragaria ×ananassa Duchesne) and tomato fruit reduces the severity of infection by Botrytis cinerea (Pers.) Fr. (gray mold) and Rhizopus stolonifer (Ehrenb.) Fr. (Rhizopus rot) and delays ripening (El Ghaouth et al., 1991; El Ghaouth et al., 1992c). Chitosan interferes with macerating enzyme production in B. cinerea when applied to the stem scars of bell pepper fruit (El Ghaouth et al., 1997). Our previous results showed that chitosan affects growth, morphology, and toxin production by A. alternata (Reddy et al., 1998), and multiplica- tion and secretion of macerating enzymes by Erwinia carotovora ssp. carotovora (Jones) Bergey et al. (bacterial soft rot), in inoculated potato tissue (Solanum tuberosum L.) (Reddy et al., 1997). These observations revealed that chitosan, in addition to its direct antimicrobial activity, also interferes with pathogenic factors and induces host defenses. We report herein the mecha- nisms of chitosan action in controlling the progress of blackmold rot in postharvest tomato fruit.
Subfields: Biomaterials, Plant Science
View Paper: https://www.semanticscholar.org/paper/890e5e09eb0a4602964b4975b62be913056d96b2
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Citations in the corpus
- Chitosan as a potential natural compound to control pre and postharvest diseases of horticultural commodities (2006, background): “…of fungal virulence factors such as cell wall degrading enzymes (polygalacturonase, pectate lyase and cellulose), organic acids (oxalic and fumaric acids), and host specific toxins (alternariol and alternariol monomethylether) and induced production of rishitin (Bhaskara Reddy et al., 1998, 2000b).”
- The efficacy of combined application of edible coatings and thyme oil in inducing resistance components in avocado (Persea americana Mill.) against anthracnose during post-harvest storage (2014, unknown): “CH coating was reported to retain fruit firmness by inhibiting the macerating enzyme activity such as polygalacturonase, pectate lyase, and cellulase in tomatoes (Reddy et al., 2000) and peaches (Atkinson et al, 2012).”
- A Biopolymer Chitosan and Its Derivatives as Promising Antimicrobial Agents against Plant Pathogens and Their Applications in Crop Protection (2011, background): “The effects of chitosan on growth inhibition of plant pathogenic fungi in fruits and vegetables were correlated with the reduction of aflatoxin, elicitation of phytoalexin and phenolic precursors, enhanced production of chitinases, and other factors relevant to the plant defenses [220, 381, 382].”