scholarly journals Salicylic acid mediated immune response of Citrus sinensis to varying frequencies of herbivory and pathogen inoculation

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Freddy Ibanez ◽  
Joon Hyuk Suh ◽  
Yu Wang ◽  
Monique Rivera ◽  
Mamoudou Setamou ◽  
...  
Keyword(s):  
Immune Response ◽  
Salicylic Acid ◽  
Citrus Sinensis ◽  
Plant Immunity ◽  
Critical Role ◽  
Transcriptional Responses ◽  
The Face ◽  
Inoculation Access Period ◽  
Citrus Leaves

Abstract Background Plant immunity against pathogens and pests is comprised of complex mechanisms orchestrated by signaling pathways regulated by plant hormones [Salicylic acid (SA) and Jasmonic acid (JA)]. Investigations of plant immune response to phytopathogens and phloem-feeders have revealed that SA plays a critical role in reprogramming of the activity and/or localization of transcriptional regulators via post-translational modifications. We explored the contributing effects of herbivory by a phytopathogen vector [Asian citrus psyllid, Diaphorina citri] and pathogen [Candidatus Liberibacter asiaticus (CaLas)] infection on response of sweet orange [Citrus sinensis (L.) Osbeck] using manipulative treatments designed to mimic the types of infestations/infections that citrus growers experience when cultivating citrus in the face of Huanglongbing (HLB) disease. Results A one-time (7 days) inoculation access period with CaLas-infected vectors caused SA-associated upregulation of PR-1, stimulating defense response after a long period of infection without herbivory (270 and 360 days). In contrast, while repeated (monthly) ‘pulses’ of 7 day feeding injury by psyllids stimulated immunity in CaLas-infected citrus by increasing SA in leaves initially (up to 120 days), long-term (270 and 360 days) repeated herbivory caused SA to decrease coincident with upregulation of genes associated with SA metabolism (BMST and DMR6). Similarly, transcriptional responses and metabolite (SA and its analytes) accumulation in citrus leaves exposed to a continuously reproducing population of D. citri exhibited a transitory upregulation of genes associated with SA signaling at 120 days and a posterior downregulation after long-term psyllid (adults and nymphs) feeding (270 and 360 days). Conclusions Herbivory played an important role in regulation of SA accumulation in mature leaves of C. sinensis, whether or not those trees were coincidentally infected with CaLas. Our results indicate that prevention of feeding injury inflicted by D. citri from the tritrophic interaction may allow citrus plants to better cope with the consequences of CaLas infection, highlighting the importance of vector suppression as a component of managing this cosmopolitan disease.

scholarly journals Salicylic acid mediated immune response of Citrus Sinensis to varying frequencies of herbivory and pathogen inoculation

2020 ◽  
Author(s):  
Freddy Ibanez ◽  
Joon Hyuk Suh ◽  
Yu Wang ◽  
Monique Rivera ◽  
Mamoudou Setamou ◽  
...  
Keyword(s):  
Immune Response ◽  
Salicylic Acid ◽  
Defense Response ◽  
Citrus Sinensis ◽  
Sweet Orange ◽  
Defense Responses ◽  
Insect Vector ◽  
Diaphorina Citri ◽  
Liberibacter Asiaticus

AbstractPlant immunity against pathogens and pests is comprised of complex mechanisms orchestrated by signaling pathways regulated by plant hormones [Salicylic acid (SA) and Jasmonic acid (JA)]. Investigations of plant immune response to phytopathogens and phloem-feeders have revealed that SA plays a critical role in reprogramming of the activity and/or localization of transcriptional regulators via post-translational modifications. We explored the contributing effects of herbivory by a phytopathogen vector [Asian citrus psyllid, Diaphorina citri] and pathogen [Candidatus Liberibacter asiaticus (CLas)] infection on response of sweet orange [Citrus sinensis (L.) Osbeck] using manipulative treatments designed to mimic the types of infestations/infections that citrus growers experience when cultivating citrus in the face of Huanglongbing (HLB) disease. A one-time (7 d) inoculation access period with CLas-infected vectors caused SA-associated upregulation of PR-1, stimulating defense response after a long period of infection without herbivory (270 and 330 days). In contrast, while repeated (monthly) ‘pulses’ of 7 d psyllid feeding injury stimulated immunity in CLas-infected citrus by increasing [SA] in leaves initially (up to 120 d), long-term (270 and 330 days) repeated herbivory caused [SA] to decrease coincident with upregulation of genes associated with SA metabolism (BMST and DMR6). Similarly, transcriptional responses and metabolite (SA and its analytes) accumulation in citrus exposed to a continuously reproducing population of D. citri exhibited a transitory upregulation of genes associated with SA signaling at 120 days and a posterior downregulation after long-term psyllid (adults and nymphs) feeding (270 and 330 days). Herbivory played an important role in regulation of SA accumulation in mature leaves of C. sinensis, whether or not those trees were coincidentally infected with CLas. Our results indicate that prevention of feeding injury inflicted by D. citri from the tritrophic interaction may allow citrus plants to better cope with the consequences of CLas infection, highlighting the importance of vector suppression as a component of managing this cosmopolitan disease.Author SummaryWe explored tritrophic interactions among an insect vector (Diaphorina citri) – phytopathogen (Candidatus Liberibacter asiaticus) – and cultivated fruit crop [sweet orange, Citrus sinensis (L) Osbeck]. Transcriptional and metabolic responses of plants were analyzed over an extended time-course of disease progression after various frequencies of herbivore feeding and durations of pathogen infection using manipulative treatments designed to mimic the types of infestations/infections that citrus growers experience when cultivating citrus in the presence of the devastating citrus disease, huanglongbing. We found that in the absence of coincident psyllid feeding damage, citrus trees could mount a defense response against the pathogen by activating the salicylic acid (SA) pathway. Repeated, monthly ‘pulses’ of herbivory led to pronounced stimulation of SA transcription that was coincident with diminished pathogen titers in plants. Although insect injury initially activated SA-dependent defense responses, continuous and/or long-term (≥ 270 d) herbivory shut down PR-1-dependent defense responses against the pathogen. Our results provide a mechanism explaining how vector suppression contributes to maintaining health of cultivated citrus in areas where huanglongbing is endemic. Our results also point to specific gene targets that may yield novel genotypes expressing tolerance against CLas after appropriate manipulations.

scholarly journals Long-term, Sustained Feeding by Asian citrus psyllid Disrupts Salicylic Acid Homeostasis in Sweet Orange

2019 ◽  
Author(s):  
Freddy Ibanez ◽  
Joon Hyuk Suh ◽  
Yu Wang ◽  
Lukasz L. Stelinski
Keyword(s):  
Salicylic Acid ◽  
Methyl Ester ◽  
Molecular Mechanisms ◽  
Sweet Orange ◽  
Plant Immunity ◽  
Dihydroxybenzoic Acid ◽  
Expression Of Genes ◽  
Continuous Feeding ◽  
Citrus Leaves ◽  
Phloem Feeding

Abstract Background Phloem-feeding insects are known to modulate the salicylic acid (SA) signaling pathway in various plant-insect interaction models. Diaphorina citri is a phloem feeding vector of a deadly phytopathogen and interactions with its host that may modulate plant defense are not well understood. The objectives of this study were to investigate the molecular mechanisms involved in transcriptional regulation of SA modification and activation of defense-associated responses in sweet orange ( Citrus sinensis ) exposed to various durations (7-, 14- and 150- days) of continuous feeding by D. citri .. Results We quantified expression of genes involved in SA pathway activation and subsequent modification, as well as, associated SA metabolites (SA methyl ester, 2,3-Dihydroxybenzoic acid and SA 2-O-β-D-glucoside). NPR1 and PR-1 expression was upregulated in plants exposed to continuous feeding by D. citri for 14 days. Expression of BSMT-like , MES1-like and DMR6-like oxygenase , as well as, accumulation of their respective SA metabolites (SA methyl ester, 2,3-Dihydroxybenzoic acid) was significantly higher in plants exposed to continuous feeding by D. citri for 150 days than in those without D. citri infestation. Concomitantly, expression of UGT74F2-like was significantly downregulated and its metabolite, salicylic acid 2-β-D-glucoside, was highly accumulated in trees exposed to 150 d of feeding compared to control trees without D. citri . Conclusions D. citri herbivory differentially regulated transcription and SA-metabolite accumulation in citrus leaves, depending on duration of insect feeding. Our results suggest that prolonged and uninterrupted exposure (150 d) of citrus to D. citri feeding suppressed plant immunity and inhibited growth, which may highlight the importance of vector suppression as part of HLB management in citrus.

scholarly journals Differential Methylation of Epstein-Barr Virus Latency Promoters Facilitates Viral Persistence in Healthy Seropositive Individuals

1999 ◽  
Vol 73 (12) ◽  
pp. 9959-9968 ◽  
Author(s):  
Emily J. Paulson ◽  
Samuel H. Speck
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Viral Genome ◽  
Epstein Barr Virus ◽  
Critical Role ◽  
Viral Gene ◽  
Barr Virus ◽  
Ebv Infection ◽  
Epstein Barr

ABSTRACT Epstein-Barr virus (EBV) establishes a life-long infection in humans, with distinct viral latency programs predominating during acute and chronic phases of infection. Only a subset of the EBV latency-associated antigens present during the acute phase of EBV infection are expressed in the latently infected memory B cells that serve as the long-term EBV reservoir. Since the EBV immortalization program elicits a potent cellular immune response, downregulation of viral gene expression in the long-term latency reservoir is likely to facilitate evasion of the immune response and persistence of EBV in the immunocompetent host. Tissue culture and tumor models of restricted EBV latency have consistently demonstrated a critical role for methylation of the viral genome in maintaining the restricted pattern of latency-associated gene expression. Here we extend these observations to demonstrate that the EBV genomes in the memory B-cell reservoir are also heavily and discretely methylated. This analysis reveals that methylation of the viral genome is a normal aspect of EBV infection in healthy immunocompetent individuals and is not restricted to the development of EBV-associated tumors. In addition, the pattern of methylation very likely accounts for the observed inhibition of the EBV immortalization program and the establishment and maintenance of a restricted latency program. Thus, EBV appears to be the first example of a parasite that usurps the host cell-directed methylation system to regulate pathogen gene expression and thereby establish a chronic infection.

Identification of MaWRKY40 and MaDLO1 as effective marker genes for tracking the salicylic acid-mediated immune response in bananas

2021 ◽  
Author(s):  
Yuh Tzean ◽  
Bo-Han Hou ◽  
Shu-Ming Tsao ◽  
Ho-Ming Chen ◽  
An-Po Cheng ◽  
...  
Keyword(s):  
Immune Response ◽  
Salicylic Acid ◽  
Fungal Pathogen ◽  
Plant Immunity ◽  
Marker Genes ◽  
Aa Genome ◽  
The Common ◽  
Leaves And Roots ◽  
Race 4 ◽  
Banana Cultivar

Bananas lie among the world’s most important cash and staple crops but are threatened by various devastating pathogens. The phytohormone salicylic acid (SA) plays a key role in the regulation of plant immune response. Tracking the expression of SA-responsive marker genes under pathogen infection is important in pathogenesis elucidation. However, the common SA-responsive marker genes are not consistently induced in different banana cultivars or different organs. Here, we conducted transcriptome analysis for SA response of a banana cultivar, ‘Pei-Chiao’ (Cavendish, AAA genome), and identified three genes, MaWRKY40, MaWRKY70, and Downy Mildew Resistant 6 (DMR6)-Like Oxygenase 1 (MaDLO1) that are robustly induced upon SA treatment in both the leaves and roots. Consistent induction of these three genes by SA treatment was also detected in both the leaves and roots of bananas belonging to different genome types such as ‘Tai-Chiao No. 7’ (Cavendish, AAA genome), ‘Pisang Awak’ (ABB genome), and ‘Lady Finger’ (AA genome). Furthermore, the biotrophic pathogen cucumber mosaic virus elicited the expression of MaWRKY40 and MaDLO1 in infected-leaves of susceptible cultivars. The hemi-biotrophic fungal pathogen Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) also consistently induced the expression of MaWRKY40 and MaDLO1 in the infected-roots of the Foc TR4-resistant cultivar. These results indicate that MaWRKY40 and MaDLO1 can serve as reliable SA-responsive marker genes for the study of plant immunity in banana. Revealing SA-responsive marker genes provides a stepping-stone for further studies in banana resistance to pathogens.

scholarly journals Arabidopsis MED18 Interaction With RNA Pol IV and V Subunit NRPD2a in Transcriptional Regulation of Plant Immune Responses

2021 ◽  
Vol 12 ◽  
Author(s):  
Yan Zhang ◽  
Chengchen Shi ◽  
Weihong Fu ◽  
Xiaojing Gu ◽  
Ziyang Qi ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Jasmonic Acid ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Epigenetic Regulation ◽  
Plant Immunity ◽  
Critical Role ◽  
Regulation Of Gene Expression ◽  
Transcriptome Profiling ◽  
Pol Iv

Mediator is a conserved multiprotein complex important for transcription by RNA polymerase II (Pol II). Arabidopsis Mediator subunit MED18 regulates flowering, hormone signaling and plant immunity. Here we report that Arabidopsis MED18 interacted with NUCLEAR RNA POLYMERASE D2a (NRPD2a), the second largest subunit of the nuclear Pol IV and V, which function in RNA-directed DNA methylation and epigenetic regulation of gene expression. Mutants for both MED18 and NRPD2a were compromised in resistance to necrotrophic fungal pathogen Botrytis cinerea. Mutants for NRPD1a, the largest subunit of Pol IV, were also compromised in resistance to Botrytis, supporting a critical role of Pol IV and V in plant defense against Botrytis. Increased Botrytis susceptibility of both the med18 and nrpd2a mutants were associated with reduced accumulation of reactive oxygen species, which are known to promote resistance to Botrytis. Both the basal and pathogen-induced levels of salicylic acid and jasmonic acid were also significantly altered in the med18 and nrpd2a mutants. Transcriptome profiling found that MED18 and NRPD2a affected both unique and overlapping sets of genes in a broad spectrum of biological processes and pathways that influence plant–pathogen interaction. The genes altered in expression in the med18 and nrpd2a mutants include disease resistance proteins, salicylic acid and jasmonic acid signaling and responses, which are known to affect resistance to necrotrophic pathogens. The novel interaction between subunits of Mediator and plant-specific RNA polymerases provides a new mechanism for epigenetic regulation of resistance and expression of defense-related genes in plant immunity.

scholarly journals Long-term, sustained feeding by Asian citrus psyllid disrupts salicylic acid homeostasis in sweet orange

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Freddy Ibanez ◽  
Joon Hyuk Suh ◽  
Yu Wang ◽  
Lukasz L. Stelinski
Keyword(s):  
Salicylic Acid ◽  
Methyl Ester ◽  
Molecular Mechanisms ◽  
Sweet Orange ◽  
Plant Immunity ◽  
Expression Of Genes ◽  
Pathway Activation ◽  
Continuous Feeding ◽  
Citrus Leaves ◽  
Phloem Feeding

Abstract Background Phloem-feeding insects are known to modulate the salicylic acid (SA) signaling pathway in various plant-insect interaction models. Diaphorina citri is a phloem feeding vector of the deadly phytopathogens, Candidatus Liberibacter americanus and Candidatus Liberibacter asiaticus, and the interactions of D. citri with its host that may modulate plant defenses are not well understood. The objectives of this study were to investigate the molecular mechanisms involved in transcriptional regulation of SA modification and activation of defense-associated responses in sweet orange (Citrus sinensis) exposed to various durations (7-, 14- and 150- days) of continuous feeding by D. citri. Results We quantified expression of genes involved in SA pathway activation and subsequent modification, as well as, associated SA metabolites (SA methyl ester, 2,3-DHBA, and SA 2-O-β-D-glucoside). NPR1 and PR-1 expression was upregulated in plants exposed to continuous feeding by D. citri for 14 days. Expression of BSMT-like, MES1-like and DMR6-like oxygenase, as well as, accumulation of their respective SA metabolites (SA methyl ester, 2,3-DHBA) was significantly higher in plants exposed to continuous feeding by D. citri for 150 days than in those without D. citri infestation. Concomitantly, expression of UGT74F2-like was significantly downregulated and its metabolite, SA 2-β-D-glucoside, was highly accumulated in trees exposed to 150 d of feeding compared to control trees without D. citri. Conclusions D. citri herbivory differentially regulated transcription and SA-metabolite accumulation in citrus leaves, depending on duration of insect feeding. Our results suggest that prolonged and uninterrupted exposure (150 d) of citrus to D. citri feeding suppressed plant immunity and inhibited growth, which may highlight the importance of vector suppression as part of huanglongbing (HLB) management in citrus.

Challenges, Concerns, and Perspectives for Poland's Energy Transition during Global COVID-19 Pandemic

2020 ◽  
Vol 1 (2) ◽  
pp. 169-173
Author(s):  
Andrzej Lorkowski ◽  
Robert Jeszke
Keyword(s):  
Internal Energy ◽  
Energy Transition ◽  
Energy Transformation ◽  
Modern Times ◽  
Current Discussion ◽  
The Face ◽  
National Governments ◽  
The Eu ◽  
At Home

The whole world is currently struggling with one of the most disastrous pandemics to hit in modern times – Covid-19. Individual national governments, the WHO and worldwide media organisations are appealing for humanity to universally stay at home, to limit contact and to stay safe in the ongoing fight against this unseen threat. Economists are concerned about the devastating effect this will have on the markets and possible outcomes. One of the countries suffering from potential destruction of this situation is Poland. In this article we will explain how difficult internal energy transformation is, considering the long-term crisis associated with the extraction and usage of coal, the European Green Deal and current discussion on increasing the EU 2030 climate ambitions. In the face of an ongoing pandemic, the situation becomes even more challenging with each passing day.

Antiretroviral Treatment-Associated Labia Majora Lipohypertrophy: A Rare Case and Plastic Surgical Treatment Options

2017 ◽  
Vol 2 (1) ◽  
pp. 43
Author(s):  
Akmal Hisham ◽  
Devananthan Ilenghoven ◽  
Wan Syazli Wan Ahmad Kamal ◽  
Salina Ibrahim ◽  
Shah Jumaat Mohd Yussof
Keyword(s):  
Highly Active Antiretroviral Therapy ◽  
Daily Living ◽  
Treatment Options ◽  
Hiv Positive ◽  
Highly Active ◽  
Labia Majora ◽  
The Face ◽  
Central Fat

The emergence of highly active antiretroviral therapy (HAART) has revolutionized the prognosis of HIV-infected patients. However, the extended use of HAART is associated with a disfiguring complication termed lipodystrophy, a disorder of body fat maldistribution causing peripheral fat loss (lipoatrophy) and central fat accumulation (lipohypertrophy). Lipoatrophy commonly affects the face, legs, buttocks and arm, whilst lipohypertrophy frequently favours the abdomen, breast and dorsocervical region. To our knowledge, we present only the second documented case in the literature of a labia majora lipohypertrophy in a HIV-positive patient receiving long-term HAART. The severity of labial abnormality caused significant physical and functional morbidities. Labiaplasty with dermolipectomy of the labia majora and excisional lipectomy of the mons pubis was successfully performed. At a 6-month follow-up, patient had no recurrence with resolution of symptoms and resumption of normal activities of daily living (ADL).

Populist Parties in Lithuania: Curious Case of Party Order and Justice and its Leadership

2019 ◽  
Vol 7 (1) ◽  
pp. 120-137 ◽  
Author(s):  
Mindaugas Jurkynas
Keyword(s):  
Party System ◽  
Leadership Selection ◽  
Political Careers ◽  
New Parties ◽  
Selection Rules ◽  
Electoral Support ◽  
The Face

AbstractThe article discusses conceptualisation of populism, Lithuania’s party system and electoral dynamics and their relation to the sustainability of populist parties. Special attention is given to Party Order and Justice, a former populist and protest party, and its leadership, namely to the issues related to scope and competencies of a leader’s intra-partisan power, leadership selection rules and history, development of leaders’ political careers and their electoral activity. The L ithuanian party system now exhibits moderate fragmentation without centrifugal tendencies. Voter volatility is still relatively high, yet the share of new parties has dropped to zero. The protest and populist parties in Lithuania went into the margins of political establishment. Popularity of the Order and Justice party has long been connected to the formerly impeached president Rolandas Paksas. His long-term leadership in the face of plummeting electoral support and an emphasis on his political martyrdom resulted in poor electoral performances, ensuing internal squabbles and his departure. Party Order and Justice’s internal regulations, however, remained favourable to strong leadership.

The Many Faces of Socioeconomic Change

2017 ◽  
Author(s):  
John Toye
Keyword(s):  
Socioeconomic Development ◽  
Adam Smith ◽  
First Century ◽  
Social Progress ◽  
Long Time ◽  
The Face ◽  
Scientific Expertise ◽  
The Many ◽  
Century Development

This book provides a survey of different ways in which economic sociocultural and political aspects of human progress have been studied since the time of Adam Smith. Inevitably, over such a long time span, it has been necessary to concentrate on highlighting the most significant contributions, rather than attempting an exhaustive treatment. The aim has been to bring into focus an outline of the main long-term changes in the way that socioeconomic development has been envisaged. The argument presented is that the idea of socioeconomic development emerged with the creation of grand evolutionary sequences of social progress that were the products of Enlightenment and mid-Victorian thinkers. By the middle of the twentieth century, when interest in the accelerating development gave the topic a new impetus, its scope narrowed to a set of economically based strategies. After 1960, however, faith in such strategies began to wane, in the face of indifferent results and general faltering of confidence in economists’ boasts of scientific expertise. In the twenty-first century, development research is being pursued using a research method that generates disconnected results. As a result, it seems unlikely that any grand narrative will be created in the future and that neo-liberalism will be the last of this particular kind of socioeconomic theory.

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