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[学术文献 ] Integration of silicon and secondary metabolites in plants: a significant association in stress tolerance 进入全文
Journal of Experimental Botany 期刊
As sessile organisms, plants are unable to avoid being subjected to environmental stresses that negatively affect their growth and productivity. Instead, they utilize various mechanisms at the morphological, physiological, and biochemical levels to alleviate the deleterious effects of such stresses. Amongst these, secondary metabolites produced by plants represent an important component of the defense system. Secondary metabolites, namely phenolics, terpenes, and nitrogen-containing compounds, have been extensively demonstrated to protect plants against multiple stresses, both biotic (herbivores and pathogenic microorganisms) and abiotic (e.g. drought, salinity, and heavy metals). The regulation of secondary metabolism by beneficial elements such as silicon (Si) is an important topic. Silicon-mediated alleviation of both biotic and abiotic stresses has been well documented in numerous plant species. Recently, many studies have demonstrated the involvement of Si in strengthening stress tolerance through the modulation of secondary metabolism. In this review, we discuss Si-mediated regulation of the synthesis, metabolism, and modification of secondary metabolites that lead to enhanced stress tolerance, with a focus on physiological, biochemical, and molecular aspects. Whilst mechanisms involved in Si-mediated regulation of pathogen resistance via secondary metabolism have been established in plants, they are largely unknown in the case of abiotic stresses, thus leaving an important gap in our current knowledge.
[学术文献 ] Mechanisms and ecological consequences of plant defence induction and suppression in herbivore communities 进入全文
Annals of Botany 期刊
Scope The objective of this review is to evaluate (1) which strategies plants have evolved to cope with herbivores and (2) which traits herbivores have evolved that enable them to counter these defences. The primary focus is on the induction and suppression of plant defences and the review outlines how the palette of traits that determine induction/suppression of, and resistance/susceptibility of herbivores to, plant defences can give rise to exploitative competition and facilitation within ecological communities “inhabiting” a plant. Conclusions Herbivores have evolved diverse strategies, which are not mutually exclusive, to decrease the negative effects of plant defences in order to maximize the conversion of plant material into offspring. Numerous adaptations have been found in herbivores, enabling them to dismantle or bypass defensive barriers, to avoid tissues with relatively high levels of defensive chemicals or to metabolize these chemicals once ingested. In addition, some herbivores interfere with the onset or completion of induced plant defences, resulting in the plant’s resistance being partly or fully suppressed. The ability to suppress induced plant defences appears to occur across plant parasites from different kingdoms, including herbivorous arthropods, and there is remarkable diversity in suppression mechanisms. Suppression may strongly affect the structure of the food web, because the ability to suppress the activation of defences of a communal host may facilitate competitors, whereas the ability of a herbivore to cope with activated plant defences will not. Further characterization of the mechanisms and traits that give rise to suppression of plant defences will enable us to determine their role in shaping direct and indirect interactions in food webs and the extent to which these determine the coexistence and persistence of species.
[学术文献 ] Chemical priming of plant defense responses to pathogen attacks 进入全文
Frontiers in Plant Science 期刊
Plants can acquire an improved resistance against pathogen attacks by exogenous application of natural or artificial compounds. In a process called chemical priming, application of these compounds causes earlier, faster and/or stronger responses to pathogen attacks. The primed defense may persist over a stress-free time (lag phase) and may be expressed also in plant organs that have not been directly treated with the compound. This review summarizes the current knowledge on the signaling pathways involved in chemical priming of plant defense responses to pathogen attacks. Chemical priming in induced systemic resistance (ISR) and systemic acquired resistance (SAR) is highlighted. The roles of the transcriptional coactivator NONEXPRESSOR OF PR1 (NPR1), a key regulator of plant immunity, induced resistance (IR) and salicylic acid signaling during chemical priming are underlined. Finally, we consider the potential usage of chemical priming to enhance plant resistance to pathogens in agriculture.
[学术文献 ] Synthetic elicitors-induced defense in crops against herbivory: A review 进入全文
Plant Science 期刊
Synthetic elicitors are non-toxic chemicals and safe for the environment when applied to plants in a variety of ways. They have been shown to interact with defense mechanisms of plants and cause the production of a wide range of valuable secondary metabolites, both volatile and non-volatile. Plants primed with chemical elicitors are indirectly induced to increase their resistance to herbivore attacks in addition to imparting tolerance or resistance to nearby plants against biotic stresses. The market is stocked with jasmonic acid, salicylic acid, and their derivatives/analogues, which have been shown to either repel or attract herbivores. While phytotoxicity has only been documented in a small number of cases, a significant increase in yield has been reported in a wide range of crops. This review includes a detailed summary of various field and laboratory experiments elucidating the mechanism of action and efficacies of exogenous application and seed priming of synthetic phytohormones on plant growth, development, and yield of different crops.
[学术文献 ] Symbiosis vs pathogenesis in plants: Reflections and perspectives 进入全文
Microbial Pathogenesis 期刊
Plant-microbe partnerships constitute a complex and intricately woven network of connections that have evolved over countless centuries, involving both cooperation and antagonism. In various contexts, plants and microorganisms engage in mutually beneficial partnerships that enhance crop health and maintain balance in ecosystems. However, these associations also render plants susceptible to a range of pathogens. Understanding the fundamental molecular mechanisms governing these associations is crucial, given the notable susceptibility of plants to external environmental influences. Based on quorum sensing signals, phytohormone, and volatile organic carbon (VOC) production and others molecules, microorganisms influence plant growth, health, and defense responses. This review explores the multifaceted relationships between plants and their associated microorganisms, encompassing mutualism, commensalism, and antagonism. The molecular mechanisms of symbiotic and pathogenic interactions share similarities but lead to different outcomes. While symbiosis benefits both parties, pathogenesis harms the host. Genetic adaptations optimize these interactions, involving coevolution driving process. Environmental factors influence outcomes, emphasizing the need for understanding and manipulation of microbial communities for beneficial results. Research directions include employing multi-omics techniques, functional studies, investigating environmental factors, understanding evolutionary trajectories, and harnessing knowledge to engineer synthetic microbial consortia for sustainable agriculture and disease management.
[学术文献 ] Jasmonic Acid (JA) Signaling Pathway in Rice Defense Against Chilo suppressalis Infestation 进入全文
Rice 期刊
Jasmonic acid (JA) signaling plays a crucial role in rice defense against the striped stem borer, Chilo suppressalis, a notorious pest causing significant yield losses. This review explores the current understanding of JA-mediated defense mechanisms in rice, focusing on the molecular basis, regulatory elements, and practical implications for pest management. JA biosynthesis and signaling pathways are induced upon C. suppressalis infestation, leading to the activation of various defense responses. These include upregulation of JA-responsive genes involved in the production of proteinase inhibitors, volatile organic compounds, and other defensive compounds. The review also discusses the crosstalk between JA and other hormonal pathways, such as salicylic acid and ethylene, in fine-tuning defense responses. Structural modifications in rice plants, such as cell wall reinforcement and accumulation of secondary metabolites, have been highlighted as key components of JA-mediated defense against C. suppressalis. Furthermore, the practical applications of this knowledge in breeding insect-resistant rice varieties and developing sustainable pest management strategies were explored. Future research directions are proposed to further elucidate the complexities of JA signaling in rice-insect interactions and harness this knowledge to enhance crop protection.
