scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Non-Chemical Treatments for the Pre- and Post-Harvest Elicitation of Defense Mechanisms in the Fungi–Avocado Pathosystem

TL;DR: In this article, the authors present the most relevant advances in the use of natural compounds with antifungal and elicitor effects in plant tissues, showing some of them to have elicitor and fungicidal effects that are reflected in the postharvest quality of the fruit and a lower incidence of diseases.
Abstract: The greatest challenge for the avocado (Persea americana Miller) industry is to maintain the quality of the fruit to meet consumer requirements. Anthracnose is considered the most important disease in this industry, and it is caused by different species of the genus Colletotrichum, although other pathogens can be equally important. The defense mechanisms that fruit naturally uses can be triggered in response to the attack of pathogenic microorganisms and also by the application of exogenous elicitors in the form of GRAS compounds. The elicitors are recognized by receptors called PRRs, which are proteins located on the avocado fruit cell surface that have high affinity and specificity for PAMPs, MAMPs, and DAMPs. The activation of defense-signaling pathways depends on ethylene, salicylic, and jasmonic acids, and it occurs hours or days after PTI activation. These defense mechanisms aim to drive the pathogen to death. The application of essential oils, antagonists, volatile compounds, chitosan and silicon has been documented in vitro and on avocado fruit, showing some of them to have elicitor and fungicidal effects that are reflected in the postharvest quality of the fruit and a lower incidence of diseases. The main focus of these studies has been on anthracnose diseases. This review presents the most relevant advances in the use of natural compounds with antifungal and elicitor effects in plant tissues.
Citations
More filters
Journal ArticleDOI
31 Aug 2022-Plants
TL;DR: In this article , the authors evaluated the effect of polylactic acid (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) 60/40 biodegradable blends added with pine essential oil (PEO) at 10, 12, 14, and 20% and coated with 1% chitosan (CH).
Abstract: For sale in the domestic market, Hass avocados are kept in non-biodegradable plastic nets and stored at an ambient temperature. The fungus Colletotrichum gloeosporioides can cause important losses at this stage. Consequently, formulations based on polylactic acid (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) 60/40 biodegradable blends added with pine essential oil (PEO) at 10, 12, 14, and 20% and coated with 1% chitosan (CH) were used for the elaboration of nets, which were evaluated on C. gloeosporioides and Rhizopus stolonifer on nutrient media and fruit and on the ripening behavior of Hass avocados at ambient temperature. The spore germination stage of C. gloeosporioides was the most extensively damaged (78% inhibition). The incidence of anthracnose was notably reduced by almost 80% in the avocados stored in the 60/40 PLA/PBAT nets coated with 1% CH. The overall values regarding weight loss, °Brix, and dry matter were c.a. 23.5%, 7.5, and 24.5%, respectively. The changes in firmness, color, and CO2 production were particularly associated with the initial harvest index and storage temperature rather than with the nets. In future research, essays on nets should include evaluations at the commercial levels.

1 citations

Journal ArticleDOI
01 Feb 2023-Plants
TL;DR: In this article , the efficacy of 11 commercial alternative products were evaluated in vitro, in growth chamber, in open field and in postharvest environments, and the best alternative product, Biorend, significantly reduced disease incidence and severity, but with lower efficacy than copper.
Abstract: Citrus production is worldwide threatened by Colletotrichum spp., causal agents of pre- and postharvest anthracnose. The recent limitation on the use of copper-based antimicrobials, due to its demonstrated noxious effect on the environment, makes the control of this pathogen difficult. Thus, alternative products able to reduce/phase out copper in organic citrus farming are needed. In this study, the efficacy of 11 commercial alternative products were evaluated in vitro, in growth chamber, in open field and in postharvest environments. In vitro, mineral fertilizers, basic substances, essential oils, plant defense stimulators and biological control agents were able to inhibit the mycelial growth with variable efficacy. On artificially infected citrus fruit, almost all tested products significantly reduced disease incidence and severity, but with lower efficacy than copper. The efficacy of mineral fertilizers-based Kiram and Vitibiosap 458 Plus, citrus essential oil-based Prev-Am Plus and chitosan-based Biorend was confirmed in open field trials, in naturally infected citrus fruits. In these trials Biorend was the best alternative product, significantly reducing disease incidence (71% DI reduction) with better results than copper (47.5%). Field treatments reduced the incidence and severity of the disease in postharvest conditions, especially in fruits field-treated three times. Overall, selected products tested in open field can represent a good alternative to copper compounds in the view of future limitation of its use.

1 citations

Book ChapterDOI
22 Mar 2023
TL;DR: In this article , the authors describe the current status of the role of mycorrhizal-induced resistance (MIR) in plant disease protection and reveal that AMF can suppress pests and plant diseases by the activation of defense regulatory genes.
Abstract: Soil fungi of the phylum Glomeromycota and plants form arbuscular mycorrhizal (AM) symbiosis. The AM fungi, during the symbiosis, establish a sink for plant photosynthate by utilizing it for biomass and metabolic energy, while the AM plants obtain nutrients and water through the AMF hyphae. The benefits of AM symbiosis on plant fitness include better mineral nutrition, especially those that are immobile in soil solution (e.g., phosphorus, copper, and zinc), and higher tolerance of mycorrhizal plants to abiotic stresses, such as drought, salinity, high soil temperature, presence of heavy metals, and others abiotic factors. Recent studies have revealed that AMF can suppress pests and plant diseases by the activation of defense regulatory genes. The knowledge of the mechanisms behind the induction of resistance by mycorrhizal symbiosis (mycorrhizal-induced resistance [MIR]) remains unknown. This chapter describes the current advanced status of the role of MIR in plant disease protection.
References
More filters
Journal ArticleDOI
16 Nov 2006-Nature
TL;DR: A detailed understanding of plant immune function will underpin crop improvement for food, fibre and biofuels production and provide extraordinary insights into molecular recognition, cell biology and evolution across biological kingdoms.
Abstract: Many plant-associated microbes are pathogens that impair plant growth and reproduction. Plants respond to infection using a two-branched innate immune system. The first branch recognizes and responds to molecules common to many classes of microbes, including non-pathogens. The second responds to pathogen virulence factors, either directly or through their effects on host targets. These plant immune systems, and the pathogen molecules to which they respond, provide extraordinary insights into molecular recognition, cell biology and evolution across biological kingdoms. A detailed understanding of plant immune function will underpin crop improvement for food, fibre and biofuels production.

10,539 citations

Journal ArticleDOI
TL;DR: Findings suggest that, at least in part, the encountered beneficial effects of essential oils are due to prooxidant effects on the cellular level.

6,174 citations

Journal ArticleDOI
14 Jun 2001-Nature
TL;DR: The current knowledge of recognition-dependent disease resistance in plants is reviewed, and a few crucial concepts are included to compare and contrast plant innate immunity with that more commonly associated with animals.
Abstract: Plants cannot move to escape environmental challenges. Biotic stresses result from a battery of potential pathogens: fungi, bacteria, nematodes and insects intercept the photosynthate produced by plants, and viruses use replication machinery at the host's expense. Plants, in turn, have evolved sophisticated mechanisms to perceive such attacks, and to translate that perception into an adaptive response. Here, we review the current knowledge of recognition-dependent disease resistance in plants. We include a few crucial concepts to compare and contrast plant innate immunity with that more commonly associated with animals. There are appreciable differences, but also surprising parallels.

3,814 citations

Journal ArticleDOI
TL;DR: Current evidence indicates that MAMPs, DAMPs, and effectors are all perceived as danger signals and induce a stereotypic defense response, and the importance of MAMP/PRR signaling for plant immunity is highlighted.
Abstract: Microbe-associated molecular patterns (MAMPs) are molecular signatures typical of whole classes of microbes, and their recognition plays a key role in innate immunity. Endogenous elicitors are similarly recognized as damage-associated molecular patterns (DAMPs). This review focuses on the diversity of MAMPs/DAMPs and on progress to identify the corresponding pattern recognition receptors (PRRs) in plants. The two best-characterized MAMP/PRR pairs, flagellin/FLS2 and EF-Tu/EFR, are discussed in detail and put into a phylogenetic perspective. Both FLS2 and EFR are leucine-rich repeat receptor kinases (LRR-RKs). Upon treatment with flagellin, FLS2 forms a heteromeric complex with BAK1, an LRR-RK that also acts as coreceptor for the brassinolide receptor BRI1. The importance of MAMP/PRR signaling for plant immunity is highlighted by the finding that plant pathogens use effectors to inhibit PRR complexes or downstream signaling events. Current evidence indicates that MAMPs, DAMPs, and effectors are all perceived as danger signals and induce a stereotypic defense response.

2,801 citations

Journal ArticleDOI
TL;DR: Genetically manipulating the Si uptake capacity of the root might help plants to accumulate more Si and, hence, improve their ability to overcome biotic and abiotic stresses.

1,471 citations