Article

Chitosan in Plant Protection

University of Manitoba, Department of Plant Science, 222, Agriculture Building, Winnipeg, Manitoba, R3T 2N2, Canada.
Marine Drugs (Impact Factor: 2.85). 04/2010; 8(4):968-87. DOI: 10.3390/md8040968
Source: PubMed

ABSTRACT

Chitin and chitosan are naturally-occurring compounds that have potential in agriculture with regard to controlling plant diseases. These molecules were shown to display toxicity and inhibit fungal growth and development. They were reported to be active against viruses, bacteria and other pests. Fragments from chitin and chitosan are known to have eliciting activities leading to a variety of defense responses in host plants in response to microbial infections, including the accumulation of phytoalexins, pathogen-related (PR) proteins and proteinase inhibitors, lignin synthesis, and callose formation. Based on these and other proprieties that help strengthen host plant defenses, interest has been growing in using them in agricultural systems to reduce the negative impact of diseases on yield and quality of crops. This review recapitulates the properties and uses of chitin, chitosan, and their derivatives, and will focus on their applications and mechanisms of action during plant-pathogen interactions.

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    • "Among its several application areas, chitosan has been shown to control preharvest and postharvest plant diseases (Romanazzi et al. in press). Chitosan has eliciting activities that can lead to a variety of defense responses to microbial infections in host plants, which include the accumulation of phytoalexins, pathogenrelated proteins, and proteinase inhibitors and the induction of lignin synthesis and callose formation (El Hadrami et al. 2010). Moreover, chitosan can also form physical barriers around the penetration sites of pathogens (Romanazzi et al. 2009), which can prevent them from spreading to healthy tissue, and fungicidal activities of chitosan have been documented against various fungi (Feliziani et al. 2013). "
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    ABSTRACT: Grapevine downy mildew (GDM) is one of the most serious diseases of grapevines. With limitations in the use of copper-based products imposed for organic agriculture by the European Union, research for alternatives is encouraged. The aim of this research was to follow a two-year trial to evaluate the control of GDM using some alternative compounds, and to determine their effects on shoot growth, plant photosynthesis, and grape quality and quantity. Under low disease pressure, Bordeaux mixture, copper hydroxide, laminarin combined with low copper, and 0.5% and 0.8% chitosan had the lowest GDM incidence, reduced on leaves by 96%, 95%, 75%, 56% and 81%, respectively, compared to the untreated control in the last survey. With high disease pressure, Bordeaux mixture, laminarin combined with Saccharomyces extracts, and 0.5% and 0.8% chitosan had the lowest GDM incidence, reduced on grapes by 86%, 37%, 66% and 75%, respectively, compared to the untreated control in the survey of mid-July. Chitosan at 0.8% lowered net photosynthesis, due to reduced stomatal conductance, leaf area, and dry weight, with no negative effects observed on the quantity of the grapes and the quality parameters of their juice. Among the alternatives to copper, chitosan provided the best GDM protection and reduced the vigour of the vegetation, inducing physiological changes without negative impacts on grape production.
    No preview · Article · Jan 2016 · Plant Disease
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    • "Among its several application areas, chitosan has been shown to control preharvest and postharvest plant diseases (Romanazzi et al. in press). Chitosan has eliciting activities that can lead to a variety of defense responses to microbial infections in host plants, which include the accumulation of phytoalexins, pathogenrelated proteins, and proteinase inhibitors and the induction of lignin synthesis and callose formation (El Hadrami et al. 2010). Moreover, chitosan can also form physical barriers around the penetration sites of pathogens (Romanazzi et al. 2009), which can prevent them from spreading to healthy tissue, and fungicidal activities of chitosan have been documented against various fungi (Feliziani et al. 2013). "

    Full-text · Dataset · Dec 2015
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    • "Elicitors including methyl salicylate, and chitosan as well as NaCl were utilized to stimulate the plant stress response to increase the anti-diabetic activity of W. somnifera. Methyl salicylate and chitosan have been shown to be very effective at inducing the plant defense response (Ament et al., 2010; El Hadrami et al., 2010). Methyl salicylate is a natural plant derivative of salicylic acid implicated as an airborne signal involved with systemic acquired resistance (Shah et al., 2014). "
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    ABSTRACT: Withania somnifera, known in India as Asghawhanda, is used traditionally to treat many medical problems including diabetes and has demonstrated therapeutic activity in various animal models as well as in diabetic patients. While much of W. somnifera's therapeutic activity is attributed to withanolides, their role in the anti-diabetic activity of W. somnifera has not been adequately studied. In the present study, we evaluated the anti-diabetic activity of W. somnifera extract and purified withanolides, as well as the effect of various elicitors on this activity. W. somnifera leaf and root extracts increased glucose uptake in myotubes and adipocytes in a dose dependent manner, with the leaf extract more active than the root extract. Leaf but not root extract increased insulin secretion in basal pancreatic beta cells but not in stimulated cells. Six withanolides isolated from W. somnifera were tested for anti-diabetic activity based on glucose uptake in skeletal myotubes. Withaferin A was found to increase glucose uptake, with 10μM producing a 54% increase compared with control, suggesting that withaferin A is at least partially responsible for W. somnifera's anti-diabetic activity. Elicitors applied to the root growing solutions affected the physiological state of the plants, altering membrane leakage or osmotic potential. Methyl salicylate and chitosan increased withaferin A content by 75% and 69% respectively, and extracts from elicited plants increased glucose uptake to a higher extent than non-elicited plants, demonstrating a correlation between increased content of withaferin A and anti-diabetic activity. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Full-text · Article · Mar 2015 · Phytochemistry
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