Impact of parasitoid-associated polydnaviruses on plant-mediated herbivore interactions
6
Citation
63
Reference
10
Related Paper
Citation Trend
Abstract Plants respond to herbivore attack by launching 2 types of defenses: direct defense and indirect defense. Direct defense includes all plant traits that increase the resistance of host plants to insect herbivores by affecting the physiology and/or behavior of the attackers. Indirect defense includes all traits that by themselves do not have significant direct impact on the attacking herbivores, but can attract natural enemies of the herbivores and thus reduce plant loss. When plants recognize herbivore‐associated elicitors, they produce and release a blend of volatiles that can attract predators, parasites, and other natural enemies. Known herbivore‐associated elicitors include fatty acid–amino acid conjugates, sulfur‐containing fatty acids, fragments of cell walls, peptides, esters, and enzymes. Identified plant volatiles include terpenes, nitrogenous compounds, and indoles. In addition, constitive traits including extrafloral nectars, food bodies, and domatia can be further induced to higher levels and attract natural enemies as well as provide food and shelter to carnivores. A better understanding of indirect plant defense at global and componential levels via advanced high throughput technologies may lead to utilization of indirect defense in suppression of herbivore damage to plants.
Defence mechanisms
Chemical defense
Cite
Citations (346)
Plants are nutritious and hence herbivores and phytopathogens have specialized to attack and consume them. In turn, plants have evolved adaptations to detect and withstand these attacks. Such adaptations we call 'defenses' and they can operate either directly between the plant and the plant consumer or indirectly i.e. when taking effect via other organisms such as predators and parasitoids of herbivores. Plant defenses put selection pressure on plant-consumers and, as a result, herbivores and pathogens have evolved counter-adaptations to avoid, resist, or manipulate plant defenses. Here we review how plant consumers have adapted to cope with plant defenses and we will put special emphasis on the phenomenon of suppression of plant defenses.
Plant life
Cite
Citations (73)
Plants in nature, which are continuously challenged by diverse insect herbivores, produce constitutive and inducible defenses to reduce insect damage and preserve their own fitness. In addition to inducing pathways that are directly responsible for the production of toxic and deterrent compounds, insect herbivory causes numerous changes in plant primary metabolism. Whereas the functions of defensive metabolites such as alkaloids, terpenes, and glucosinolates have been studied extensively, the fitness benefits of changes in photosynthesis, carbon transport, and nitrogen allocation remain less well understood. Adding to the complexity of the observed responses, the feeding habits of different insect herbivores can significantly influence the induced changes in plant primary metabolism. In this review, we summarize experimental data addressing the significance of insect feeding habits, as related to herbivore-induced changes in plant primary metabolism. Where possible, we link these physiological changes with current understanding of their underlying molecular mechanisms. Finally, we discuss the potential fitness benefits that host plants receive from altering their primary metabolism in response to insect herbivory.
Secondary metabolism
Primary metabolite
Primary (astronomy)
Cite
Citations (259)
Plants have been interacting with insects for several hundred million years, leading to the development of an intricate and dynamic defense system against insect herbivores. This defense system is further categorized as direct and indirect defense responses based on their expression. Specific or direct defensive responses are mediated by various morphological, biochemical and molecular mechanisms to counteract the effects of herbivore attack while indirect defense is mediated by releasing volatile mixtures to attract natural enemies of plant eating insect herbivores. The structural defense includes both morphological and anatomical traits viz., thorns, spines etc., whereas biochemical mechanisms of defense against the herbivores are wide-ranging, highly dynamic and includes production of different secondary metabolites-terpenes, phenolics and N-containing compounds. The molecular defense mechanisms include intracellular wound signalling viz., systemin signalling and jasmonate regulation of defense responsive genes. The defensive compounds are developed either constitutively or in response to plant damage, affecting insect herbivores’ feeding, development, and survival. In addition, plants also release volatile organic compounds which attract the herbivores’ natural enemies. These strategies either act independently or in conjunction with each other.
Cite
Citations (3)
Plants respond to insect herbivory with a myriad of inducible responses, broadly categorized as direct defenses and indirect defenses. Herbivore-induced plant direct defenses include the production of toxic metabolites and proteins. Direct defenses can negatively affect a herbivore's physiology, but exact large resource demands on plant metabolism. Plants can also defend themselves against herbivores indirectly by emitting specific blends of volatiles that attract carnivorous natural enemies. Herbivore-induced plant volatiles can be triggered by some insect specific elicitors. Multiple signaling transduction pathways are involved in plant defense responses to insect herbivores, and they can interact with each other, either synergistically or antagonistically. Understanding herbivore-induced plant responses can provide important information for the complement of integrated pest management tactics.
Defence mechanisms
Cite
Citations (4)
The research progress in the chemical defense of plant to mammalian herbivore was reviewed in this paper. The plant secondary compounds mainly are phenolics, terpenoids and nitrogen-containing compounds. The defense efficiency of plant to mammalian herbivores is different with the types and content of secondary compounds in plant. Secondary compounds inhibited the foraging of mammalian herbivores by affecting the intake, digestion, metabolites and reproduction of animal. It is the main trends to study the mode of coevolution of plant and animals mediated by plant secondary compounds.
Coevolution
Chemical defense
Terrestrial plant
Plant reproduction
Cite
Citations (0)
Benzoxazinoids are a class of indole-derived plant chemical defenses comprising compounds with a 2-hydroxy-2H-1,4-benzoxazin-3(4H)-one skeleton and their derivatives. These phytochemicals are widespread in grasses, including important cereal crops such as maize, wheat and rye, as well as a few dicot species, and display a wide range of antifeedant, insecticidal, antimicrobial, and allelopathic activities. Although their overall effects against insect herbivores are frequently reported, much less is known about how their modes of action specifically influence insect physiology. The present review summarizes the biological activities of benzoxazinoids on chewing, piercing-sucking, and root insect herbivores. We show how within-plant distribution modulates the exposure of different herbivore feeding guilds to these defenses, and how benzoxazinoids may act as toxins, feeding deterrents and digestibility-reducing compounds under different conditions. In addition, recent results on the metabolism of benzoxazinoids by insects and their consequences for plant-herbivore interactions are addressed, as well as directions for future research.
Allelopathy
Cite
Citations (203)
Cite
Citations (4)
In all natural habitats, plants are surrounded by an enormous number of potential enemies (biotic) and various kinds of abiotic environmental stress, greatly responsible for heavy reduction in crop productivity. To counter the herbivore attack, plants produce defensive compounds that appear to have no direct function in growth and development. These substances are known as secondary metabolites. Secondary metabolites, including terpenes, phenolics and nitrogen (N) containing compounds, defend plants against a variety of insect herbivores. These compounds are either produced constitutively or in response to plant damage, and affect feeding, growth, and survival of herbivores. Many compounds act directly on the herbivore, whereas others act indirectly via the attraction of organisms from other trophic levels that, in turn, protect the plant. The role of secondary metabolites in defense may involve deterrent and anti-feedant activity, toxicity or acting as precursors to physical defense systems. By virtue of their biological activities against insect herbivores, many of these substances are employed commercially as insecticides, while others find uses as fragrances, flavorings, medicinal drugs, and industrial materials.
Defence mechanisms
Secondary metabolite
Biotic stress
Cite
Citations (6)
Plants respond to herbivory through various morphological, biochemicals, and molecular mechanisms to counter/offset the effects of herbivore attack. The biochemical mechanisms of defense against the herbivores are wide-ranging, highly dynamic, and are mediated both by direct and indirect defenses. The defensive compounds are either produced constitutively or in response to plant damage, and affect feeding, growth, and survival of herbivores. In addition, plants also release volatile organic compounds that attract the natural enemies of the herbivores. These strategies either act independently or in conjunction with each other. However, our understanding of these defensive mechanisms is still limited. Induced resistance could be exploited as an important tool for the pest management to minimize the amounts of insecticides used for pest control. Host plant resistance to insects, particularly, induced resistance, can also be manipulated with the use of chemical elicitors of secondary metabolites, which confer resistance to insects. By understanding the mechanisms of induced resistance, we can predict the herbivores that are likely to be affected by induced responses. The elicitors of induced responses can be sprayed on crop plants to build up the natural defense system against damage caused by herbivores. The induced responses can also be engineered genetically, so that the defensive compounds are constitutively produced in plants against are challenged by the herbivory. Induced resistance can be exploited for developing crop cultivars, which readily produce the inducible response upon mild infestation, and can act as one of components of integrated pest management for sustainable crop production.
Defence mechanisms
Cite
Citations (1,722)