Silicon control of bacterial and viral diseases in plants

AbstractSilicon plays an important role in providing tolerance to various abiotic stresses and augmenting plant resistance against diseases. However, there is a paucity of reports about the effect of silicon on bacterial and viral pathogens of plants. In general, the effect of silicon on plant resistance against bacterial diseases is considered to be due to either physical defense or increased biochemical defense. In this study, the interaction between silicon foliar or soil-treatments and reduced bacterial and viral severity was reviewed. The current review explains the agricultural importance of silicon in plants, refers to the control of bacterial pathogens in different crop plants by silicon application, and underlines the different mechanisms of silicon-enhanced resistance. A section about the effect of silicon in decreasing viral disease intensity was highlighted. By combining the data presented in this study, a better comprehension of the complex interaction between silicon foliar- or soil-applications and bacterial and viral plant diseases could be achieved.

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The Diagnosis of Viral Disease by Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010005398x ◽

1982 ◽

Vol 40 ◽

pp. 270-273

Author(s):

William B. McCombs ◽

Cameron E. McCoy

Keyword(s):

Electron Microscopy ◽

Hospital Stay ◽

Viral Infections ◽

Medical Profession ◽

Bacterial Pathogens ◽

Viral Disease ◽

Viral Pathogens ◽

Academic Interest ◽

The Past

Recent years have brought a reversal in the attitude of the medical profession toward the diagnosis of viral infections. Identification of bacterial pathogens was formerly thought to be faster than identification of viral pathogens. Viral identification was dismissed as being of academic interest or for confirming the presence of an epidemic, because the patient would recover or die before this could be accomplished. In the past 10 years, the goal of virologists has been to present the clinician with a viral identification in a matter of hours. This fast diagnosis has the potential for shortening the patient's hospital stay and preventing the administering of toxic and/or expensive antibiotics of no benefit to the patient.

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Genetic and Pre- and Postharvest Factors Influencing the Content of Antioxidants in Cucurbit Crops

Antioxidants ◽

10.3390/antiox10060894 ◽

2021 ◽

Vol 10 (6) ◽

pp. 894

Author(s):

Cecilia Martínez ◽

Juan Luis Valenzuela ◽

Manuel Jamilena

Keyword(s):

Abiotic Stresses ◽

Nutritional Value ◽

Antioxidant Properties ◽

Plant Diseases ◽

Human Diet ◽

Antioxidant Power ◽

Factors Influencing ◽

Cultivated Species ◽

Plant Families ◽

Valuable Compounds

Cucurbitaceae is one of the most economically important plant families, and includes some worldwide cultivated species like cucumber, melons, and squashes, and some regionally cultivated and feral species that contribute to the human diet. For centuries, cucurbits have been appreciated because of their nutritional value and, in traditional medicine, because of their ability to alleviate certain ailments. Several studies have demonstrated the remarkable contents of valuable compounds in cucurbits, including antioxidants such as polyphenols, flavonoids, and carotenoids, but also tannins and terpenoids, which are abundant. This antioxidant power is beneficial for human health, but also in facing plant diseases and abiotic stresses. This review brings together data on the antioxidant properties of cucurbit species, addressing the genetic and pre- and postharvest factors that regulate the antioxidant content in different plant organs. Environmental conditions, management, storage, and pre- and postharvest treatments influencing the biosynthesis and activity of antioxidants, together with the biodiversity of this family, are determinant in improving the antioxidant potential of this group of species. Plant breeding, as well as the development of innovative biotechnological approaches, is also leading to new possibilities for exploiting cucurbits as functional products.

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Improved Plant Resistance by Phytomicrobiome Community Towards Biotic and Abiotic Stresses

Phytomicrobiome Interactions and Sustainable Agriculture ◽

10.1002/9781119644798.ch11 ◽

2021 ◽

pp. 207-216

Author(s):

Neha Trivedi

Keyword(s):

Plant Resistance ◽

Abiotic Stresses ◽

Biotic And Abiotic Stresses

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Aktualitások a sérült immunitású betegek cytomegalovirusinfekcióinak ellátásában. II. Terápiás lehetőségek és ellátási stratégiák

Orvosi Hetilap ◽

10.1556/650.2019.31320 ◽

2019 ◽

Vol 160 (10) ◽

pp. 363-369 ◽

Cited By ~ 1

Author(s):

János Sinkó

Keyword(s):

Treatment Options ◽

Viral Disease ◽

Controlled Clinical Trial ◽

Cell Mediated Immunity ◽

Cell Transplant ◽

Clinical Use ◽

Viral Pathogens ◽

Transplant Patients ◽

Cytomegalovirus Reactivation ◽

New Treatment

Abstract: Although cytomegalovirus is one of the most prevalent viral pathogens on the globe, in immunocompetent individuals infected with cytomegalovirus usually no specific antiviral therapy is required. In the case of impaired T-cell mediated immunity, however, latent infection can reactivate and occasionally a viral disease with organ involvement develops. The number of actually available anti-cytomegalovirus drugs is low, for prophylaxis or treatment ganciclovir, valganciclovir, foscarnet or cidofovir can be administered. The clinical use of these drugs is primarily hampered by their toxicity. In search for new treatment options, only letermovir, a terminase complex inhibitor compound showed appropriate activity and tolerability. In a placebo-controlled clinical trial on prophylactic letermovir in stem cell transplant patients, administration of the active compound resulted in a significant decrease in human cytomegalovirus reactivations as well as in prolonged survival. No toxicity affecting clinical use has been observed. For management of patients being at high risk for cytomegalovirus reactivation, appropriate antiviral strategy should be followed. Antiviral prophylaxis or diagnostics-guided pre-emptive therapy seem to be the most suitable options. Orv Hetil. 2019; 160(10): 363–369.

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Adult Plant Resistance in Maize to Northern Leaf Spot Is a Feature of Partial Loss-of-function Alleles ofHm1

10.1101/244491 ◽

2018 ◽

Author(s):

Sandeep R. Marla ◽

Kevin Chu ◽

Satya Chintamanani ◽

Dilbag Multani ◽

Antje Klempien ◽

...

Keyword(s):

Disease Resistance ◽

Resistance Genes ◽

Plant Resistance ◽

Leaf Spot ◽

Adult Plant Resistance ◽

Plant Diseases ◽

Adult Plant ◽

Hc Toxin ◽

Differential Transcription

ABSTRACTAdult plant resistance (APR) is an enigmatic phenomenon in which resistance genes are ineffective in protecting seedlings from disease but confer robust resistance at maturity. Maize has multiple cases in which genes confer APR to northern leaf spot, a lethal disease caused byCochliobolus carbonumrace 1 (CCR1). The first identified case of APR in maize is encoded by a hypomorphic allele,Hm1A, at thehm1locus. In contrast, wild type alleles ofhm1provide complete protection at all developmental stages and in every part of the maize plant.Hm1encodes an NADPH-dependent reductase, which inactivates HC-toxin, a key virulence effector of CCR1. Cloning and characterization ofHm1Aruled out differential transcription or translation for its APR phenotype and identified an amino acid substitution that reduced HC-toxin reductase (HCTR) activity. The possibility of a causal relationship between the weak nature ofHm1Aand its APR phenotype was confirmed by the generation of two new APR alleles ofHm1by mutagenesis. The HCTRs encoded by these new APR alleles had undergone relatively conservative missense changes that partially reduced their enzymatic activity similar to HM1A. No difference in accumulation of HCTR was observed between adult and juvenile plants, suggesting that the susceptibility of seedlings derives from a greater need for HCTR activity, not reduced accumulation of the gene product. Conditions and treatments that altered the photosynthetic output of the host had a dramatic effect on resistance imparted by the APR alleles, demonstrating a link between the energetic or metabolic status of the host and disease resistance affected by HC-toxin catabolism by the APR alleles of HCTR.AUTHOR SUMMARYAdult plant resistance (APR) is a phenomenon in which disease resistance genes are able to confer resistance at the adult stages of the plant but somehow fail to do so at the seedling stages. Despite the widespread occurrence of APR in various plant diseases, the mechanism underlying this trait remains obscure. It is not due to the differential transcription of these genes, and here we show that it is also not due to the differential translation or activity of the APR alleles of the maizehm1gene at different stages of development. Using a combination of molecular genetics, biochemistry and physiology, we present multiple lines of evidence that demonstrate that APR is a feature or symptom of weak forms of resistance. While the mature parts of the plant are metabolically robust enough to manifest resistance, seedling tissues are not, leaving them vulnerable to disease. Growth conditions that compromise the photosynthetic output of the plant further deteriorate the ability of the seedlings to protect themselves from pathogens.One sentence summaryCharacterization of adult plant resistance in the maize-CCR1 pathosystem reveals a causal link between weak resistance and APR.

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Role of the gut microbiota in airway immunity and host defense against respiratory infections

Biological Chemistry ◽

10.1515/hsz-2021-0281 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Maike Willers ◽

Dorothee Viemann

Keyword(s):

Gut Microbiota ◽

Host Defense ◽

Gut Microbiome ◽

Respiratory Infections ◽

Current Knowledge ◽

Viral Pathogens ◽

Commensal Microbiota ◽

Enhanced Resistance ◽

The Impact

Abstract Colonization of the intestine with commensal bacteria is known to play a major role in the maintenance of human health. An altered gut microbiome is associated with various ensuing diseases including respiratory diseases. Here, we summarize current knowledge on the impact of the gut microbiota on airway immunity with a focus on consequences for the host defense against respiratory infections. Specific gut commensal microbiota compositions and functions are depicted that mediate protection against respiratory infections with bacterial and viral pathogens. Lastly, we highlight factors that have imprinting effects on the establishment of the gut microbiota early in life and are potentially relevant in the context of respiratory infections. Deepening our understanding of these relationships will allow to exploit the knowledge on how gut microbiome maturation needs to be modulated to ensure lifelong enhanced resistance towards respiratory infections.

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Loss of rice PARAQUAT TOLERANCE 3 confers enhanced resistance to abiotic stresses and increases grain yield in field

Plant Cell & Environment ◽

10.1111/pce.13856 ◽

2020 ◽

Vol 43 (11) ◽

pp. 2743-2754

Author(s):

Alamin Alfatih ◽

Jie Wu ◽

Sami Ullah Jan ◽

Zi‐Sheng Zhang ◽

Jin‐Qiu Xia ◽

...

Keyword(s):

Grain Yield ◽

Abiotic Stresses ◽

Enhanced Resistance ◽

Paraquat Tolerance

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The Probing Behavior Component of Disease Transmission in Insect-Transmitted Bacterial Plant Pathogens

Insects ◽

10.3390/insects10070212 ◽

2019 ◽

Vol 10 (7) ◽

pp. 212 ◽

Cited By ~ 1

Author(s):

Timothy A. Ebert

Keyword(s):

Host Plant ◽

Plant Resistance ◽

Host Plant Resistance ◽

Disease Transmission ◽

Plant Pathogens ◽

Management Strategies ◽

Resistance Mechanism ◽

Electrical Circuit ◽

Plant Diseases ◽

Candidatus Liberibacter

Insects can be effective vectors of plant diseases and this may result in billions of dollars in lost agricultural productivity. New, emerging or introduced diseases will continue to cause extensive damage in afflicted areas. Understanding how the vector acquires the pathogen and inoculates new hosts is critical in developing effective management strategies. Management may be an insecticide applied to kill the vector or a host plant resistance mechanism to make the host plant less suitable for the vector. In either case, the tactic must act before the insect performs the key behavior(s) resulting in either acquisition or transmission. This requires knowledge of the timing of behaviors the insect uses to probe the plant and commence ingestion. These behaviors are visualized using electropenetrography (EPG), wherein the plant and insect become part of an electrical circuit. With the tools to define specific steps in the probing process, we can understand the timing of acquisition and inoculation. With that understanding comes the potential for more relevant testing of management strategies, through insecticides or host plant resistance. The primary example will be Candidatus Liberibacter asiaticus transmitted by Diaphorina citri Kuwayama in the citrus agroecosystem, with additional examples used as appropriate.

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