Faculty Opinions recommendation of Auxin promotes susceptibility to Pseudomonas syringae via a mechanism independent of suppression of salicylic acid-mediated defenses.

2013 ◽  
Author(s):  
Keith Davis
Keyword(s):  
Salicylic Acid ◽  
Pseudomonas Syringae

scholarly journals Uncoupling Salicylic Acid-Dependent Cell Death and Defense-Related Responses From Disease Resistance in the Arabidopsis Mutant acd5

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 341-350
Author(s):  
Jean T Greenberg ◽  
F Paul Silverman ◽  
Hua Liang
Keyword(s):  
Cell Death ◽  
Salicylic Acid ◽  
Disease Resistance ◽  
Pseudomonas Syringae ◽  
Higher Plants ◽  
Ethylene Signaling ◽  
Symptom Development ◽  
Wild Type ◽  
Dependent Cell ◽  
Arabidopsis Mutant

Abstract Salicylic acid (SA) is required for resistance to many diseases in higher plants. SA-dependent cell death and defense-related responses have been correlated with disease resistance. The accelerated cell death 5 mutant of Arabidopsis provides additional genetic evidence that SA regulates cell death and defense-related responses. However, in acd5, these events are uncoupled from disease resistance. acd5 plants are more susceptible to Pseudomonas syringae early in development and show spontaneous SA accumulation, cell death, and defense-related markers later in development. In acd5 plants, cell death and defense-related responses are SA dependent but they do not confer disease resistance. Double mutants with acd5 and nonexpressor of PR1, in which SA signaling is partially blocked, show greatly attenuated cell death, indicating a role for NPR1 in controlling cell death. The hormone ethylene potentiates the effects of SA and is important for disease symptom development in Arabidopsis. Double mutants of acd5 and ethylene insensitive 2, in which ethylene signaling is blocked, show decreased cell death, supporting a role for ethylene in cell death control. We propose that acd5 plants mimic P. syringae-infected wild-type plants and that both SA and ethylene are normally involved in regulating cell death during some susceptible pathogen infections.

scholarly journals Systemic Acquired Resistance in Canola Is Linked with Pathogenesis-Related Gene Expression and Requires Salicylic Acid

2007 ◽  
Vol 97 (7) ◽  
pp. 794-802 ◽  
Author(s):  
Shobha D. Potlakayala ◽  
Darwin W. Reed ◽  
Patrick S. Covello ◽  
Pierre R. Fobert
Keyword(s):  
Salicylic Acid ◽  
Pseudomonas Syringae ◽  
Systemic Acquired Resistance ◽  
Induced Defense ◽  
Acquired Resistance ◽  
Microbial Pathogens ◽  
Broad Host Range ◽  
Avirulent Strain ◽  
Enhanced Resistance ◽  
Pathogenesis Related

Systemic acquired resistance (SAR) is an induced defense response that confers long-lasting protection against a broad range of microbial pathogens. Here we show that treatment of Brassica napus plants with the SAR-inducing chemical benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) significantly enhanced resistance against virulent strains of the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Leptosphaeria maculans. Localized preinoculation of plants with an avirulent strain of P. syringae pv. maculicola also enhanced resistance to these pathogens but was not as effective as BTH treatment. Single applications of either SAR-inducing pretreatment were effective against P. syringae pv. maculicola, even when given more than 3 weeks prior to the secondary challenge. The pretreatments also led to the accumulation of pathogenesis-related (PR) genes, including BnPR-1 and BnPR-2, with higher levels of transcripts observed in the BTH-treatment material. B. napus plants expressing a bacterial salicylate hydroxylase transgene (NahG) that metabolizes salicylic acid to catechol were substantially compromised in SAR and accumulated reduced levels of PR gene transcripts when compared with untransformed controls. Thus, SAR in B. napus displays many of the hallmarks of classical SAR including long lasting and broad host range resistance, association with PR gene activation, and a requirement for salicylic acid.

scholarly journals Ultraviolet radiation enhances salicylic acid-mediated defense signaling and resistance to Pseudomonas syringae DC3000 in a jasmonic acid-deficient tomato mutant

2019 ◽  
Vol 14 (4) ◽  
pp. e1581560 ◽  
Author(s):  
Rocío Escobar Bravo ◽  
Gang Chen ◽  
Katharina Grosser ◽  
Nicole M. Van Dam ◽  
Kirsten A. Leiss ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Jasmonic Acid ◽  
Ultraviolet Radiation ◽  
Pseudomonas Syringae ◽  
Defense Signaling ◽  
Tomato Mutant

scholarly journals Chitosan Oligosaccharide Induces Resistance to Pseudomonas syringae pv. tomato DC3000 in Arabidopsis thaliana by Activating Both Salicylic Acid– and Jasmonic Acid–Mediated Pathways

2018 ◽  
Vol 31 (12) ◽  
pp. 1271-1279 ◽  
Author(s):  
Xiaochen Jia ◽  
Haihong Zeng ◽  
Wenxia Wang ◽  
Fuyun Zhang ◽  
Heng Yin
Keyword(s):  
Salicylic Acid ◽  
Jasmonic Acid ◽  
Induced Resistance ◽  
Pseudomonas Syringae ◽  
Plant Immunity ◽  
Chitosan Oligosaccharide ◽  
Induction Effect ◽  
Tomato Dc3000 ◽  
Expression Of Genes ◽  
Underlying Mechanisms

Chitosan oligosaccharide (COS) is an effective plant immunity elicitor; however, its induction mechanism in plants is complex and needs further investigation. In this study, the Arabidopsis–Pseudomonas syringae pv. tomato DC3000 (hereafter called DC3000) interaction was used to investigate the induction effect and the underlying mechanisms of COS. COS is effective in inducing resistance to DC3000 in Arabidopsis, and our results demonstrate that treatment with COS 3 days before DC3000 inoculation provided the most effective resistance. Disease severity in jar1 (jasmonic acid [JA]-deficient mutant), NahG, and sid2 (salicylic acid [SA]-deficient mutants) suggest both the SA and JA pathways are required for the Arabidopsis response to DC3000. COS pretreatment induced resistance in wild type (WT), jar1, and also, although to a lesser degree, in NahG and sid2 plants, implying that the SA and JA pathways play redundant roles in COS-induced resistance to DC3000. In COS-pretreated plants, expression of genes related to the SA pathway (PR1, PR2, and PR5) and SA content increased in both WT and jar1. Moreover, expression of genes related to the JA pathway (PDF1.2 and VSP2) and JA content both increased in WT and NahG. In conclusion, COS induces resistance to DC3000 in Arabidopsis by activating both SA- and JA-mediated pathways, although SA and JA pathways play redundant roles in this COS-induced resistance.

scholarly journals Bacterial Compound N,N-Dimethylhexadecylamine Modulates Expression of Iron Deficiency and Defense Response Genes in Medicago truncatula Independently of the Jasmonic Acid Pathway

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 624 ◽  
Author(s):  
Vicente Montejano-Ramírez ◽  
Ernesto García-Pineda ◽  
Eduardo Valencia-Cantero
Keyword(s):  
Gene Expression ◽  
Salicylic Acid ◽  
Iron Deficiency ◽  
Jasmonic Acid ◽  
Pseudomonas Syringae ◽  
Medicago Truncatula ◽  
Abiotic Stresses ◽  
Biotic And Abiotic Stresses ◽  
Iron Deprivation ◽  
Iron Deficient

Plants face a variety of biotic and abiotic stresses including attack by microbial phytopathogens and nutrient deficiencies. Some bacterial volatile organic compounds (VOCs) activate defense and iron-deficiency responses in plants. To establish a relationship between defense and iron deficiency through VOCs, we identified key genes in the defense and iron-deprivation responses of the legume model Medicago truncatula and evaluated the effect of the rhizobacterial VOC N,N-dimethylhexadecylamine (DMHDA) on the gene expression in these pathways by RT-qPCR. DMHDA increased M. truncatula growth 1.5-fold under both iron-sufficient and iron-deficient conditions compared with untreated plants, whereas salicylic acid and jasmonic acid decreased growth. Iron-deficiency induced iron uptake and defense gene expression. Moreover, the effect was greater in combination with DMHDA. Salicylic acid, Pseudomonas syringae, jasmonic acid, and Botrytis cinerea had inhibitory effects on growth and iron response gene expression but activated defense genes. Taken together, our results showed that the VOC DMHDA activates defense and iron-deprivation pathways while inducing a growth promoting effect unlike conventional phytohormones, highlighting that DMHDA does not mimic jasmonic acid but induces an alternative pathway. This is a novel aspect in the complex interactions between biotic and abiotic stresses.

scholarly journals The Arabidopsis Hypoxia Inducible AtR8 Long Non-Coding RNA also Contributes to Plant Defense and Root Elongation Coordinating with WRKY Genes under Low Levels of Salicylic Acid

2020 ◽  
Vol 6 (1) ◽  
pp. 8
Author(s):  
Shuang Li ◽  
Saraswati Nayar ◽  
HuiYuan Jia ◽  
Sanjay Kapoor ◽  
Juan Wu ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Pseudomonas Syringae ◽  
Root Elongation ◽  
Early Stage ◽  
Flowering Plant ◽  
Stage Of Development ◽  
Non Coding Rna ◽  
Pathogenesis Related ◽  
Low Levels ◽  
Long Non Coding Rna

AtR8 lncRNA was previously identified in the flowering plant Arabidopsis thaliana as an abundant Pol III-transcribed long non-coding RNA (lncRNA) of approximately 260 nt. AtR8 lncRNA accumulation is responsive to hypoxic stress and salicylic acid (SA) treatment in roots, but its function has not yet been identified. In this study, microarray analysis of an atr8 mutant and wild-type Arabidopsis indicated a strong association of AtR8 lncRNA with the defense response. AtR8 accumulation exhibited an inverse correlation with an accumulation of two WRKY genes (WRKY53/WRKY70) when plants were exposed to exogenous low SA concentrations (20 µM), infected with Pseudomonas syringae, or in the early stage of development. The highest AtR8 accumulation was observed 5 days after germination, at which time no WRKY53 or WRKY70 mRNA was detectable. The presence of low levels of SA resulted in a significant reduction of root length in atr8 seedlings, whereas wrky53 and wrky70 mutants exhibited the opposite phenotype. Taken together, AtR8 lncRNA participates in Pathogenesis-Related Proteins 1 (PR-1)-independent defense and root elongation, which are related to the SA response. The mutual regulation of AtR8 lncRNA and WRKY53/WRKY70 is mediated by Nonexpressor of Pathogenesis-Related Gene 1 (NPR1).

scholarly journals Signaling Crosstalk between Salicylic Acid and Ethylene/Jasmonate in Plant Defense: Do We Understand What They Are Whispering?

2019 ◽  
Vol 20 (3) ◽  
pp. 671 ◽  
Author(s):  
Ning Li ◽  
Xiao Han ◽  
Dan Feng ◽  
Deyi Yuan ◽  
Li-Jun Huang
Keyword(s):  
Salicylic Acid ◽  
Signaling Pathways ◽  
Pseudomonas Syringae ◽  
Defense Response ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Host Cells ◽  
Defense Gene Expression ◽  
Signaling Crosstalk

During their lifetime, plants encounter numerous biotic and abiotic stresses with diverse modes of attack. Phytohormones, including salicylic acid (SA), ethylene (ET), jasmonate (JA), abscisic acid (ABA), auxin (AUX), brassinosteroid (BR), gibberellic acid (GA), cytokinin (CK) and the recently identified strigolactones (SLs), orchestrate effective defense responses by activating defense gene expression. Genetic analysis of the model plant Arabidopsis thaliana has advanced our understanding of the function of these hormones. The SA- and ET/JA-mediated signaling pathways were thought to be the backbone of plant immune responses against biotic invaders, whereas ABA, auxin, BR, GA, CK and SL were considered to be involved in the plant immune response through modulating the SA-ET/JA signaling pathways. In general, the SA-mediated defense response plays a central role in local and systemic-acquired resistance (SAR) against biotrophic pathogens, such as Pseudomonas syringae, which colonize between the host cells by producing nutrient-absorbing structures while keeping the host alive. The ET/JA-mediated response contributes to the defense against necrotrophic pathogens, such as Botrytis cinerea, which invade and kill hosts to extract their nutrients. Increasing evidence indicates that the SA- and ET/JA-mediated defense response pathways are mutually antagonistic.

scholarly journals A Salicylic Acid–Induced Lectin-Like Protein Plays a Positive Role in the Effector-Triggered Immunity Response of Arabidopsis thaliana to Pseudomonas syringae Avr-Rpm1

2013 ◽  
Vol 26 (12) ◽  
pp. 1395-1406 ◽  
Author(s):  
Grace Armijo ◽  
Paula Salinas ◽  
Mariela Inés Monteoliva ◽  
Aldo Seguel ◽  
Consuelo García ◽  
...  
Keyword(s):  
Cell Death ◽  
Salicylic Acid ◽  
Pseudomonas Syringae ◽  
Functional Characterization ◽  
Constitutive Expression ◽  
Hypersensitive Reaction ◽  
Positive Role ◽  
Legume Lectin ◽  
Immunity Response ◽  
Effector Triggered Immunity

Salicylic acid (SA) is one of the key hormones that orchestrate the pathogen-induced immune response in plants. This response is often characterized by the activation of a local hypersensitive reaction involving programmed cell death, which constrains proliferation of biotrophic pathogens. Here, we report the identification and functional characterization of an SA-induced legume lectin-like protein 1 (SAI-LLP1), which is coded by a gene that belongs to the group of early SA-activated Arabidopsis genes. SAI-LLP1 expression is induced upon inoculation with avirulent strains of Pseudomonas syringae pv. tomato via an SA-dependent mechanism. Constitutive expression of SAI-LLP1 restrains proliferation of P. syringae pv. tomato Avr-Rpm1 and triggers more cell death in inoculated leaves. Cellular and biochemical evidence indicates that SAI-LLP1 is a glycoprotein located primarily at the apoplastic side of the plasma membrane. This work indicates that SAI-LLP1 is involved in resistance to P. syringae pv. tomato Avr-Rpm1 in Arabidopsis, as a component of the SA-mediated defense processes associated with the effector-triggered immunity response.

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