scholarly journals Induction of plant defense responses by Ocimum gratissimum L. (Lamiaceae) leaf extracts

2009 ◽  
Vol 35 (3) ◽  
pp. 191-195 ◽  
Author(s):  
Flávia Tavares Colpas ◽  
Kátia Regina Freitas Schwan-Estrada ◽  
José Renato Stangarlin ◽  
Maria De Lurdes Ferrarese ◽  
Carlos Alberto Scapim ◽  
...  
Keyword(s):  
Defense Response ◽  
Induced Systemic Resistance ◽  
Disease Incidence ◽  
Defense Responses ◽  
Systemic Resistance ◽  
Aqueous Extracts ◽  
Plant Defense Responses ◽  
Leaf Extracts ◽  
Ocimum Gratissimum ◽  
Chitinase Production

Aqueous extracts of the leaves of Ocimum gratissimum at 10, 25, 40 and 50% (w/v) concentrations induced the production of phytoalexins in soybean cotyledons and sorghum mesocotyls. The aqueous extracts also induced systemic resistance in cucumber to Colletotrichum lagenarium, reflected by reduction in disease incidence and an increase in chitinase production. Modes of action and the existence of possible elicitors of defense response in O. gratissimum leaf extracts are discussed.

scholarly journals Evidence of Induced Systemic Resistance Against Botrytis elliptica in Lily

2008 ◽  
Vol 98 (7) ◽  
pp. 830-836 ◽  
Author(s):  
Yi-Hung Liu ◽  
Chien-Jui Huang ◽  
Chao-Ying Chen
Keyword(s):  
Induced Systemic Resistance ◽  
Disease Incidence ◽  
Field Studies ◽  
Defense Responses ◽  
Disease Suppression ◽  
Systemic Resistance ◽  
Fatty Acid Profiles ◽  
Plant Defense Responses ◽  
Gene Expression Analyses ◽  
Glycine Rich Protein

Lily leaf blight, caused by Botrytis elliptica, is an important fungal disease in Taiwan. In order to identify an effective, nonfungicide method to decrease disease incidence in Lilium formosanum, the efficacy of rhizobacteria eliciting induced systemic resistance (ISR) was examined in this study. Over 300 rhizobacteria were isolated from the rhizosphere of L. formosanum healthy plants and 63 were identified by the analysis of fatty acid profiles. Disease suppressive ability of 13 strains was demonstrated by soil drench application of bacterial suspensions to the rhizosphere of L. formosanum seedlings. Biocontrol experiments were carried out with Bacillus cereus and Pseudomonas putida strains on L. formosanum and Lilium Oriental hybrid cvs. Acapulco and Star Gazer in greenhouse and field studies. Plants treated with B. cereus strain C1L showed that protection against B. elliptica on L. formosanum could last for at least 10 days and was consistent with high populations of B. cereus on lily roots. Analysis of the expression of LfGRP1 and LsGRP1, encoding glycine-rich protein associated with L. formosanum and cv. Star Gazer, respectively, revealed different responses induced by B. cereus or by the pathogen B. elliptica, suggesting that plant defense responses elicited by each follows a different signaling pathway. According to the results of biocontrol assays and LfGRP1/LsGRP1 gene expression analyses with culture filtrates of B. cereus strain C1L, we propose that eliciting factors of ISR are generated by B. cereus and some of them exhibit thermostable and heat-tolerant traits. This is the first report about ISR-eliciting rhizobacteria and factors effective for foliar disease suppression in lily.

scholarly journals Identification of miRNAs Involved in Bacillus velezensis FZB42-Activated Induced Systemic Resistance in Maize

2019 ◽  
Vol 20 (20) ◽  
pp. 5057 ◽  
Author(s):  
Shanshan Xie ◽  
Hengguo Yu ◽  
Enze Li ◽  
Yu Wang ◽  
Juan Liu ◽  
...  
Keyword(s):  
Defense Response ◽  
Target Genes ◽  
Induced Systemic Resistance ◽  
Systemic Resistance ◽  
Abiotic Stress Response ◽  
Bacillus Velezensis ◽  
Nuclear Factor Y ◽  
Network Analyses ◽  
Cis Element ◽  
Differentially Expressed Mirna

Bacillus velezensis FZB42 is able to activate induced systemic resistance (ISR) to enhance plant defense response against pathogen infections. Though the roles of microRNAs (miRNAs) in Bacillus-triggered ISR have been reported in Arabidopsis, the maize miRNAs responsible for the Bacillus-activated ISR process have not been discovered. To explore the maize miRNAs involved in ISR, maize miRNAs in response to FZB42 (ISR activating), FZB42△sfp△alss (deficient in triggering ISR), and a control for 12 h were sequenced. A total of 146 known miRNAs belonging to 30 miRNA families and 217 novel miRNAs were identified. Four miRNAs specifically repressed in FZB42-treatment were selected as candidate ISR-associated miRNAs. All of them contained at least one defense response-related cis-element, suggesting their potential roles in activating the ISR process. Interestingly, three of the four candidate ISR-associated miRNAs belong to the conserved miR169 family, which has previously been confirmed to play roles in abiotic stress response. Moreover, 52 mRNAs were predicted as potential targets of these candidate ISR-associated miRNAs through TargetFinder software and degradome sequencing. Gene Ontology (GO) and network analyses of target genes showed that these differentially expressed miRNA might participate in the ISR process by regulating nuclear factor Y transcription factor. This study is helpful in better understanding the regulatory roles of maize miRNAs in the Bacillus-activated ISR process.

scholarly journals Magnaporthe oryzae Systemic Defense Trigger 1 (MoSDT1)-Mediated Metabolites Regulate Defense Response in Rice

2020 ◽  
Author(s):  
Guihua Duan ◽  
Chunqin Li ◽  
Yanfang Liu ◽  
Xiaoqing Ma ◽  
Qiong Luo ◽  
...  
Keyword(s):  
Plant Defense ◽  
Defense Response ◽  
High Performance ◽  
Receptor Gene ◽  
Active Role ◽  
Defense Responses ◽  
Effector Proteins ◽  
Plant Defense Responses ◽  
Flight Mass Spectrometry ◽  
Metabolic Marker

Abstract Background: Some of the pathogenic effector proteins play an active role in stimulating the plant defense system to strengthen plant resistance.Results: In this study, ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS) was implemented to identify altered metabolites in transgenic rice containing over-expressed M. oryzae Systemic Defense Trigger 1 (MoSDT1) that was infected at three-time points. The characterized dominating metabolites were organic acids and their derivatives, organic oxygen compounds, lipids, and lipid-like molecules. Among the identified metabolites, shikimate, galactinol, trehalose, D-mannose, linolenic acid, dopamine, tyramine, and L-glutamine are precursors for the synthesis of many secondary defense metabolites Carbohydrate, as well as amino acid metabolic, pathways were revealed to be involved in plant defense responses and resistance strengthening.Conclusion: The increasing salicylic acid (SA) and jasmonic acid (JA) content enhanced interactions between JA synthesis/signaling gene, SA synthesis/receptor gene, raffinose/fructose/sucrose synthase gene, and cell wall-related genes all contribute to defense response in rice. The symptoms of rice after M. oryzae infection were significantly alleviated when treated with six identified metabolites, i.e., galactol, tyramine, L-glutamine, L-tryptophan, α-terpinene, and dopamine for 72 h exogenously. Therefore, these metabolites could be utilized as an optimal metabolic marker for M. oryzae defense.#These authors contributed equally to this work.

scholarly journals Defense Response in Slash Pine: Chitosan Treatment Alters the Abundance of Specific mRNAs

1997 ◽  
Vol 10 (1) ◽  
pp. 135-137 ◽  
Author(s):  
Mary E. Mason ◽  
John M. Davis
Keyword(s):  
Plant Defense ◽  
Cell Cultures ◽  
Cinnamic Acid ◽  
Differential Display ◽  
Defense Response ◽  
Sequence Similarity ◽  
Defense Responses ◽  
Slash Pine ◽  
Plant Defense Responses ◽  
Specific Mrnas

We used differential display to identify chitosan responsive cDNAs in slash pine cell cultures. Two clones that showed increased mRNA abundance had sequence similarity to genes with roles in major plant defense responses, clone 18 to cinnamic acid 4-hydroxylase, and clone 30 to chitinase.

scholarly journals Seaweed-Based Compounds and Products for Sustainable Protection against Plant Pathogens

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 59
Author(s):  
Pushp Sheel Shukla ◽  
Tudor Borza ◽  
Alan T. Critchley ◽  
Balakrishnan Prithiviraj
Keyword(s):  
Plant Defense ◽  
Plant Pathogens ◽  
Systemic Acquired Resistance ◽  
Plant Immunity ◽  
Crop Protection ◽  
Defense Responses ◽  
Systemic Resistance ◽  
Environmental Damage ◽  
Plant Defense Responses ◽  
Seaweed Extracts

Sustainable agricultural practices increasingly demand novel, environmentally friendly compounds which induce plant immunity against pathogens. Stimulating plant immunity using seaweed extracts is a highly viable strategy, as these formulations contain many bio-elicitors (phyco-elicitors) which can significantly boost natural plant immunity. Certain bioactive elicitors present in a multitude of extracts of seaweeds (both commercially available and bench-scale laboratory formulations) activate pathogen-associated molecular patterns (PAMPs) due to their structural similarity (i.e., analogous structure) with pathogen-derived molecules. This is achieved via the priming and/or elicitation of the defense responses of the induced systemic resistance (ISR) and systemic acquired resistance (SAR) pathways. Knowledge accumulated over the past few decades is reviewed here, aiming to explain why certain seaweed-derived bioactives have such tremendous potential to elicit plant defense responses with considerable economic significance, particularly with increasing biotic stress impacts due to climate change and the concomitant move to sustainable agriculture and away from synthetic chemistry and environmental damage. Various extracts of seaweeds display remarkably different modes of action(s) which can manipulate the plant defense responses when applied. This review focuses on both the similarities and differences amongst the modes of actions of several different seaweed extracts, as well as their individual components. Novel biotechnological approaches for the development of new commercial products for crop protection, in a sustainable manner, are also suggested.

scholarly journals Validamycin A Induces Broad-Spectrum Resistance Involving Salicylic Acid and Jasmonic Acid/Ethylene Signaling Pathways

2020 ◽  
Vol 33 (12) ◽  
pp. 1424-1437
Author(s):  
Chuanhong Bian ◽  
Yabing Duan ◽  
Jueyu Wang ◽  
Qian Xiu ◽  
Jianxin Wang ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Jasmonic Acid ◽  
Plant Defense ◽  
Signaling Pathways ◽  
Broad Spectrum ◽  
Defense Responses ◽  
Systemic Resistance ◽  
Signal Pathways ◽  
Plant Defense Responses ◽  
Validamycin A

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 .

scholarly journals Latent defense response to non-pathogenic microbial factors impairs plant-rhizobacteria mutualism

2020 ◽  
Author(s):  
Yu Yang ◽  
Shenglan Chen ◽  
Li Peng ◽  
Xiaomin Liu ◽  
Richa Kaushal ◽  
...  
Keyword(s):  
Plant Defense ◽  
Defense Response ◽  
Growth Promotion ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
New Type ◽  
Pathogenic Microbes ◽  
Arabidopsis Mutant ◽  
Hidden Layer ◽  
Mutualistic Association

ABSTRACTUnlike pathogens that trigger plant defense responses, commensal or beneficial microbes are compatible with plants and do not elicit a defense response. An assumption underlying the compatibility is that plants are inert in mounting a defense response to non-pathogenic microbial factors. However, the mechanisms underlying this inertness in defense are unknown. Here a forward genetic screen led to the isolation of an Arabidopsis mutant displaying a new type of immunity which we named as latent defense response (LDR) to a beneficial rhizobacterium. The mutant, known as gp1 for Growth-Promotion 1, is impaired in rhizobacteria-induced plant growth-promotion due to disrupted oleic acid homeostasis and consequent activation of defense responses. Several bacterial volatile compounds trigger LDR in gp1 but not wild type plants. GP1 dysfunction strongly represses colonization of the beneficial rhizobacterium and alters root-associated microbiota. Our findings reveal a hidden layer of plant defense, LDR, which is suppressed by GP1 to allow mutualistic association between plants and beneficial rhizobacteria.One Sentence SummaryA hidden layer of host immunity against non-pathogenic microbes leads to plant incompatibility with beneficial rhizobacteria.

scholarly journals Lack of Control of Citrus Canker by Induced Systemic Resistance Compounds

Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 745-750 ◽  
Author(s):  
J. H. Graham ◽  
R. P. Leite
Keyword(s):  
Induced Systemic Resistance ◽  
Disease Incidence ◽  
Citrus Canker ◽  
Systemic Resistance ◽  
Copper Hydroxide ◽  
Canker Disease ◽  
Fruit Drop ◽  
Additional Control ◽  
Lack Of Control ◽  
Swingle Citrumelo

Induced systemic resistance compounds (ISRs), acibenzolar-S-methyl (Actigard), and harpin protein (Messenger) were assayed in the greenhouse against Xanthomonas axonopodis pv. citrumelo, the cause of citrus bacterial spot (CBS), and X. axonopodis pv. citri, the cause of Asiatic citrus canker. Actigard and Messenger applied as foliar sprays 3 to 7 days before inoculation reduced numbers of lesions when either bacterium at 103 or 104 CFU/ml was injection-infiltrated into Swingle citrumelo leaves. Based on this activity, the ISRs were evaluated in southern Brazil in orchards of sweet oranges with low to moderate canker disease incidence in spray programs with and without copper oxychloride (COC) and copper hydroxide (CuOH). Actigard and Messenger were applied full season or in the first two or three sprays of a six-spray program in an attempt to reduce early canker disease on foliage and thereby reduce subsequent fruit infection and premature drop. Sprays of COC and CuOH were moderately to highly effective in reducing canker disease incidence and preventing premature fruit drop. Actigard or Messenger in combination with COC and CuOH, respectively, did not significantly reduce citrus canker incidence on foliage or fruit drop compared with Cu alone. The lack of additional control with ISRs means they cannot be recommended at this time to augment Cu programs for management of citrus canker.

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