Ralstonia solanacearum upregulates marker genes of the salicylic acid and ethylene signaling pathways but not those of the jasmonic acid pathway in leaflets of Solanum lines during early stage of infection

2016 ◽  
Vol 147 (3) ◽  
pp. 615-625 ◽  
Author(s):  
Z. Baichoo ◽  
Y. Jaufeerally-Fakim
2020 ◽  
Author(s):  
Helena Martin-Rivilla ◽  
Ana Garcia-Villaraco ◽  
Beatriz Ramos-Solano ◽  
Francisco Javier Gutierrez-Mañero ◽  
Jose Antonio Lucas

Abstract Background Unravel the complex functioning of plant immune system is essential and something in which great effort is being made since its performance is not entirely clear yet. Knowing plant immune system allows strengthening it and therefore developing a more efficient and environmentally friendly agriculture, avoiding the massive use of agrochemicals and making plants the main protagonist in the defense against pathogens.The use of beneficial rhizobacteria (bioeffectors) and its derived metabolic elicitors are biotechnological alternatives in plant immune system elicitation. The present work aimed to check the ability of 25 bacterial strains selected from a group of 175, isolated from the rhizosphere of Nicotiana glauca, to trigger the innate immune system of Arabidopsis thaliana seedlings against the pathogen Pseudomonas syringae DC3000. A study of the signal transduction pathways involved in plant response was made.Results The selected 25 strains were chosen because of their biochemical traits and avoiding phylogenetic redundancy. The 5 strains, of the previous 25, more effective in the prevention of pathogen infection were used to elucidate signal transduction pathways involved in the plant immune response, studying the differential expression of Salicylic acid and Jasmonic acid/Ethylene pathway marker genes. Some strains stimulated the two pathways with no inhibitory effects between them, while others stimulated either one or the other. Metabolic elicitors of two strains, chosen for their taxonomic affiliation and for the results obtained in the differential expression of the genes studied, were extracted using n-hexane, ethyl acetate and n-butanol, and their capacity to mimic bacterial effect to trigger the immune system of the plant was studied. N-hexane and ethyl acetate were the most effective fractions against the pathogen in both strains, achieving similar protection rates although gene expression responses were different from that obtained by the bacteria. Conclusions Beneficial rhizobacteria and its metabolic elicitors have great potential as biotechnological tools since they are able to improve plant immune system through the triggering of either Salicylic acid or Jasmonic acid/Ethylene pathway or both pathways simultaneously. These results open a huge amount of biotechnological possibilities to develop biological products for agriculture in different situations and plant species.


Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 136 ◽  
Author(s):  
Loredana Scalschi ◽  
Eugenio Llorens ◽  
Pilar García-Agustín ◽  
Begonya Vicedo

The jasmonic acid pathway has been considered as the backbone of the response against necrotrophic pathogens. However, a hemi-biotrophic pathogen, such as Pseudomonas syringae, has taken advantage of the crosstalk between the different plant hormones in order to manipulate the responses for its own interest. Despite that, the way in which Pseudomonas syringae releases coronatine to activate jasmonic acid-derived responses and block the activation of salicylic acid-mediated responses is widely known. However, the implication of the jasmonic intermediates in the plant-Pseudomonas interaction is not studied yet. In this work, we analyzed the response of both, plant and bacteria using SiOPR3 tomato plants. Interestingly, SiOPR3 plants are more resistant to infection with Pseudomonas. The gene expression of bacteria showed that, in SiOPR3 plants, the activation of pathogenicity is repressed in comparison to wild type plants, suggesting that the jasmonic acid pathway might play a role in the pathogenicity of the bacteria. Moreover, treatments with JA restore the susceptibility as well as activate the expression of bacterial pathogenicity genes. The observed results suggest that a complete jasmonic acid pathway is necessary for the susceptibility of tomato plants to Pseudomonas syringae.


2020 ◽  
Author(s):  
Yuh Tzean ◽  
Bo-Han Hou ◽  
Shu-Ming Tsao ◽  
Ho-Ming Chen ◽  
An-Po Cheng ◽  
...  

Abstract Background: Banana, an important cash and staple crop worldwide, suffers from various biotrophic and hemi-biotrophic pathogens. In plants’ defense against these pathogens, the phytohormone salicylic acid (SA) plays a key role in the regulation of immune response. Using a specific set of SA-responsive genes as markers is frequently adopted to monitor the onset of SA-mediated immune response. However, reliable SA-responsive genes marker genes have not been well established in bananas. Results: From the transcriptome analysis of SA-treated ‘Pei-Chiao’ banana roots, we identified 19 up-regulated and 3 down-regulated genes. Four of the up-regulated genes previously reported to play crucial roles in SA-mediated immunity in other species were further analyzed for their applicability in different tissues and cultivars of bananas using real-time quantitative reverse-transcription PCR. The analysis showed that WRKY40, WRKY70, and Downy Mildew Resistant 6 (DMR6)-Like Oxygenase 1 (DLO1) were significantly induced upon SA treatment in both the leaves and roots of ‘Pei-Chiao’ (AAA genome), ‘Pisang Awak’ (ABB genome), and ‘Lady Finger’ (AA genome) bananas.Conclusions: The uncovering of common marker genes WRKY40, WRKY70, and DLO1 for SA response in different banana genome types provides the stepping stone for studies towards understanding of SA-mediated immune response in bananas.


2016 ◽  
Vol 42 (12) ◽  
pp. 1212-1225 ◽  
Author(s):  
Nurmi Pangesti ◽  
Michael Reichelt ◽  
Judith E. van de Mortel ◽  
Eleni Kapsomenou ◽  
Jonathan Gershenzon ◽  
...  

2020 ◽  
Vol 33 (12) ◽  
pp. 1424-1437
Author(s):  
Chuanhong Bian ◽  
Yabing Duan ◽  
Jueyu Wang ◽  
Qian Xiu ◽  
Jianxin Wang ◽  
...  

Validamycin A (VMA) is an aminoglycoside antibiotic used to control rice sheath blight. Although it has been reported that VMA can induce the plant defense responses, the mechanism remains poorly understood. Here, we found that reactive oxygen species (ROS) bursts and callose deposition in Arabidopsis thaliana, rice (Oryza sativa L.), and wheat (Triticum aestivum L.) were induced by VMA and were most intense with 10 μg of VMA per milliliter at 24 h. Moreover, we showed that VMA induced resistance against Pseudomonas syringae, Botrytis cinerea, and Fusarium graminearum in Arabidopsis leaves, indicating that VMA induces broad-spectrum disease resistance in both dicots and monocots. In addition, VMA-mediated resistance against P. syringae was not induced in NahG transgenic plants, was partially decreased in npr1 mutants, and VMA-mediated resistance to B. cinerea was not induced in npr1, jar1, and ein2 mutants. These results strongly indicated that VMA triggers plant defense responses to both biotrophic and necrotrophic pathogens involved in salicylic acid (SA) and jasmonic acid/ethylene (JA/ET) signaling pathways and is dependent on NPR1. In addition, transcriptome analysis further revealed that VMA regulated the expression of genes involved in SA, JA/ET, abscisic acid (ABA), and auxin signal pathways. Taken together, VMA induces systemic resistance involving in SA and JA/ET signaling pathways and also exerts a positive influence on ABA and auxin signaling pathways. Our study highlights the creative application of VMA in triggering plant defense responses against plant pathogens, providing a valuable insight into applying VMA to enhance plant resistance and reduce the use of chemical pesticides. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .


2010 ◽  
Vol 23 (2) ◽  
pp. 187-197 ◽  
Author(s):  
Antonio Leon-Reyes ◽  
Yujuan Du ◽  
Annemart Koornneef ◽  
Silvia Proietti ◽  
Ana P. Körbes ◽  
...  

Cross-talk between jasmonate (JA), ethylene (ET), and Salicylic acid (SA) signaling is thought to operate as a mechanism to fine-tune induced defenses that are activated in response to multiple attackers. Here, 43 Arabidopsis genotypes impaired in hormone signaling or defense-related processes were screened for their ability to express SA-mediated suppression of JA-responsive gene expression. Mutant cev1, which displays constitutive expression of JA and ET responses, appeared to be insensitive to SA-mediated suppression of the JA-responsive marker genes PDF1.2 and VSP2. Accordingly, strong activation of JA and ET responses by the necrotrophic pathogens Botrytis cinerea and Alternaria brassicicola prior to SA treatment counteracted the ability of SA to suppress the JA response. Pharmacological assays, mutant analysis, and studies with the ET-signaling inhibitor 1-methylcyclopropene revealed that ET signaling renders the JA response insensitive to subsequent suppression by SA. The APETALA2/ETHYLENE RESPONSE FACTOR transcription factor ORA59, which regulates JA/ET-responsive genes such as PDF1.2, emerged as a potential mediator in this process. Collectively, our results point to a model in which simultaneous induction of the JA and ET pathway renders the plant insensitive to future SA-mediated suppression of JA-dependent defenses, which may prioritize the JA/ET pathway over the SA pathway during multi-attacker interactions.


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