Practical application of induced resistance to plant diseases: an appraisal of effectiveness under field conditions

2009 ◽  
Vol 147 (5) ◽  
pp. 523-535 ◽  
Author(s):  
D. R. WALTERS ◽  
J. M. FOUNTAINE
Keyword(s):  
Induced Resistance ◽  
Systemic Acquired Resistance ◽  
Regulatory Protein ◽  
Acquired Resistance ◽  
Crop Protection ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Diseases ◽  
Systemic Resistance ◽  
Plant Parts ◽  
The Impact

SUMMARYPlants resist pathogen attack through a combination of constitutive and inducible defences. Different types of induced resistance have been defined based on differences in signalling pathways and spectra of effectiveness. Systemic acquired resistance (SAR) occurs in distal plant parts following localized infection by a necrotizing pathogen. It is controlled by a signalling pathway that depends upon the accumulation of salicylic acid (SA) and the regulatory protein NPR1. In contrast, induced systemic resistance (ISR) is promoted by selected strains of non-pathogenic plant growth-promoting rhizobacteria (PGPR). ISR functions independently of SA, but requires NPR1 and is regulated by jasmonic acid (JA) and ethylene (ET).Resistance can be induced by treatment with a variety of biotic and abiotic inducers. The resistance induced is broad spectrum and can be long-lasting, but is rarely complete, with most inducing agents providing between 0·20 and 0·85 disease control. In the field, expression of induced resistance is likely to be influenced by the environment, genotype, crop nutrition and the extent to which plants are already induced. Unfortunately, understanding of the impact of these influences on the expression of induced resistance is rudimentary. So too is understanding of how best to use induced resistance in practical crop protection. This situation will need to change if induced resistance is to fulfil its potential in crop protection.

scholarly journals Polyphenol oxidase and lysozyme mediate induction of systemic resistance in tomato, when a bioelicitor is used

2015 ◽  
Vol 55 (4) ◽  
pp. 343-350 ◽  
Author(s):  
Navodit Goel ◽  
Prabir Kumar Paul
Keyword(s):  
Pseudomonas Syringae ◽  
Polyphenol Oxidase ◽  
Systemic Acquired Resistance ◽  
De Novo ◽  
Acquired Resistance ◽  
Crop Protection ◽  
Systemic Resistance ◽  
Neem Extract ◽  
Single Node ◽  
Protection Method

Abstract Tomato (Solanum lycopersicum L.) is attacked by Pseudomonas syringae pv. tomato causing heavy damage to the crops. The present study focused on the application of aqueous fruit extracts of neem (Azadirachta indica L.) on a single node of aseptically raised tomato plants. Observations were done, and the changes in the activity and isoenzyme profile of polyphenol oxidase (PPO) and lysozyme, both at the site of treatment as well as away from it, were noted. The results demonstrate that neem extract could significantly induce the activities of both the enzymes as well as upregulate the de novo expression of additional PPO isoenzymes. Induction of systemic acquired resistance (SAR) by natural plant extracts is a potent eco-friendly crop protection method.

scholarly journals Differential Effectiveness of Salicylate-Dependent and Jasmonate/Ethylene-Dependent Induced Resistance in Arabidopsis

2002 ◽  
Vol 15 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Jurriaan Ton ◽  
Johan A. Van Pelt ◽  
L. C. Van Loon ◽  
Corné M. J. Pieterse
Keyword(s):  
Induced Resistance ◽  
Xanthomonas Campestris ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Alternaria Brassicicola ◽  
Systemic Resistance ◽  
Basal Resistance ◽  
Viral Pathogen ◽  
Differential Effectiveness

Salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) are each involved in the regulation of basal resistance against different pathogens. These three signals play important roles in induced resistance as well. SA is a key regulator of pathogen-induced systemic acquired resistance (SAR), whereas JA and ET are required for rhizobacteria-mediated induced systemic resistance (ISR). Both types of induced resistance are effective against a broad spectrum of pathogens. In this study, we compared the spectrum of effectiveness of SAR and ISR using an oomycete, a fungal, a bacterial, and a viral pathogen. In noninduced Arabidopsis plants, these pathogens are primarily resisted through either SA-dependent basal resistance (Peronospora parasitica and Turnip crinkle virus [TCV]), JA/ET-dependent basal resistance responses (Alternaria brassicicola), or a combination of SA-, JA-, and ET-dependent defenses (Xanthomonas campestris pv. armoraciae). Activation of ISR resulted in a significant level of protection against A. brassicicola, whereas SAR was ineffective against this pathogen. Conversely, activation of SAR resulted in a high level of protection against P. parasitica and TCV, whereas ISR conferred only weak and no protection against P. parasitica and TCV, respectively. Induction of SAR and ISR was equally effective against X. campestris pv. armoraciae. These results indicate that SAR is effective against pathogens that in noninduced plants are resisted through SA-dependent defenses, whereas ISR is effective against pathogens that in noninduced plants are resisted through JA/ET-dependent defenses. This suggests that SAR and ISR constitute a reinforcement of extant SA- or JA/ET-dependent basal defense responses, respectively.

scholarly journals Nanogram Amounts of Salicylic Acid Produced by the Rhizobacterium Pseudomonas aeruginosa 7NSK2 Activate the Systemic Acquired Resistance Pathway in Bean

1999 ◽  
Vol 12 (5) ◽  
pp. 450-458 ◽  
Author(s):  
Geert De Meyer ◽  
Kristof Capieau ◽  
Kris Audenaert ◽  
Antony Buchala ◽  
Jean-Pierre Métraux ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Salicylic Acid ◽  
Induced Resistance ◽  
Phenylalanine Ammonia Lyase ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Systemic Resistance ◽  
Resistance Pathway ◽  
Lyase Activity ◽  
Phenylalanine Ammonia Lyase Activity

Root colonization by specific nonpathogenic bacteria can induce a systemic resistance in plants to pathogen infections. In bean, this kind of systemic resistance can be induced by the rhizobacterium Pseudomonas aeruginosa 7NSK2 and depends on the production of salicylic acid by this strain. In a model with plants grown in perlite we demonstrated that Pseudomonas aeruginosa 7NSK2-induced resistance is equivalent to the inclusion of 1 nM salicylic acid in the nutrient solution and used the latter treatment to analyze the molecular basis of this phenomenon. Hydroponic feeding of 1 nM salicylic acid solutions induced phenylalanine ammonia-lyase activity in roots and increased free salicylic acid levels in leaves. Because pathogen-induced systemic acquired resistance involves similar changes it was concluded that 7NSK2-induced resistance is mediated by the systemic acquired resistance pathway. This conclusion was validated by analysis of phenylalanine ammonia-lyase activity in roots and of salicylic acid levels in leaves of soil-grown plants treated with Pseudomonas aeruginosa. The induction of systemic acquired resistance by nanogram amounts of salicylic acid is discussed with respect to long-distance signaling in systemic acquired resistance.

scholarly journals Induced Systemic Protection Against Tomato Late Blight Elicited by Plant Growth-Promoting Rhizobacteria

2002 ◽  
Vol 92 (12) ◽  
pp. 1329-1333 ◽  
Author(s):  
Zhinong Yan ◽  
M. S. Reddy ◽  
Choong-Min Ryu ◽  
John A. McInroy ◽  
Mark Wilson ◽  
...  
Keyword(s):  
Plant Growth ◽  
Jasmonic Acid ◽  
Late Blight ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Plant Growth Promoting Rhizobacteria ◽  
Systemic Resistance ◽  
Local Resistance ◽  
Plant Growth Promoting ◽  
Growth Promoting

Two strains of plant growth-promoting rhizobacteria (PGPR), Bacillus pumilus SE34 and Pseudomonas fluorescens 89B61, elicited systemic protection against late blight on tomato and reduced disease severity by a level equivalent to systemic acquired resistance induced by Phytophthora infestans or induced local resistance by chemical inducer β-amino butyric acid (BABA) in greenhouse assays. Germination of sporangia and zoospores of P. infestans on leaf surfaces of tomato plants treated with the two PGPR strains, pathogen, and chemical BABA was significantly reduced compared with the noninduced control. Induced protection elicited by PGPR, pathogen, and BABA were examined to determine the signal transduction pathways in three tomato lines: salicylic acid (SA)-hydroxylase transgenic tomato (nahG), ethylene insensitive mutants (Nr/Nr), and jasmonic acid insensitive mutants (def1). Results suggest that induced protection elicited by both bacilli and pseudomonad PGPR strains was SA-independent but ethylene- and jasmonic acid-dependent, whereas systemic acquired resistance elicited by the pathogen and induced local resistance by BABA were SA-dependent. The lack of colonization of tomato leaves by strain 89B61 suggests that the observed induced systemic resistance (ISR) was due to systemic protection by strain 89B61 and not attributable to a direct interaction between pathogen and biological control agent. Although strain SE34 was detected on tomato leaves, ISR mainly accounted for the systemic protection with this strain.

scholarly journals Chemical sensing of plant stress at the ecosystem scale

2008 ◽  
Vol 5 (5) ◽  
pp. 1287-1294 ◽  
Author(s):  
T. Karl ◽  
A. Guenther ◽  
A. Turnipseed ◽  
E. G. Patton ◽  
K. Jardine
Keyword(s):  
Plant Hormones ◽  
Systemic Acquired Resistance ◽  
Chilling Injury ◽  
Plant Stress ◽  
Acquired Resistance ◽  
Warning Signal ◽  
Ambient Air ◽  
Aerosol Formation ◽  
Night Time ◽  
The Impact

Abstract. Significant ecosystem-scale emissions of methylsalicylate (MeSA), a semivolatile plant hormone thought to act as the mobile signal for systemic acquired resistance (SAR), were observed in an agroforest. Our measurements show that plant internal defence mechanisms can be activated in response to temperature stress and are modulated by water availability on large scales. Highest MeSA fluxes (up to 0.25 mg/m2/h) were observed after plants experienced ambient night-time temperatures of ~7.5°C followed by a large daytime temperature increase (e.g. up to 22°C). Under these conditions estimated night-time leaf temperatures were as low as ~4.6°C, likely inducing a response to prevent chilling injury. Our observations imply that plant hormones can be a significant component of ecosystem scale volatile organic compound (VOC) fluxes (e.g. as high as the total monoterpene (MT) flux) and therefore contribute to the missing VOC budget. If generalized to other ecosystems and different types of stresses these findings suggest that semivolatile plant hormones have been overlooked by investigations of the impact of biogenic VOCs on aerosol formation events in forested regions. Our observations show that the presence of MeSA in canopy air serves as an early chemical warning signal indicating ecosystem-scale stresses before visible damage becomes apparent. As a chemical metric, ecosystem emission measurements of MeSA in ambient air could therefore support field studies investigating factors that adversely affect plant growth.

scholarly journals Local Responses and Systemic Induced Resistance Mediated by Ectomycorrhizal Fungi

2020 ◽  
Vol 11 ◽  
Author(s):  
Steven Dreischhoff ◽  
Ishani S. Das ◽  
Mareike Jakobi ◽  
Karl Kasper ◽  
Andrea Polle
Keyword(s):  
Induced Resistance ◽  
Ectomycorrhizal Fungi ◽  
Molecular Mechanisms ◽  
Systemic Acquired Resistance ◽  
Induced Systemic Resistance ◽  
Systemic Resistance ◽  
Future Research ◽  
Root Tips ◽  
Long Distance ◽  
Extramatrical Mycelium

Ectomycorrhizal fungi (EMF) grow as saprotrophs in soil and interact with plants, forming mutualistic associations with roots of many economically and ecologically important forest tree genera. EMF ensheath the root tips and produce an extensive extramatrical mycelium for nutrient uptake from the soil. In contrast to other mycorrhizal fungal symbioses, EMF do not invade plant cells but form an interface for nutrient exchange adjacent to the cortex cells. The interaction of roots and EMF affects host stress resistance but uncovering the underlying molecular mechanisms is an emerging topic. Here, we focused on local and systemic effects of EMF modulating defenses against insects or pathogens in aboveground tissues in comparison with arbuscular mycorrhizal induced systemic resistance. Molecular studies indicate a role of chitin in defense activation by EMF in local tissues and an immune response that is induced by yet unknown signals in aboveground tissues. Volatile organic compounds may be involved in long-distance communication between below- and aboveground tissues, in addition to metabolite signals in the xylem or phloem. In leaves of EMF-colonized plants, jasmonate signaling is involved in transcriptional re-wiring, leading to metabolic shifts in the secondary and nitrogen-based defense metabolism but cross talk with salicylate-related signaling is likely. Ectomycorrhizal-induced plant immunity shares commonalities with systemic acquired resistance and induced systemic resistance. We highlight novel developments and provide a guide to future research directions in EMF-induced resistance.

scholarly journals Effects of Jasmonic Acid, Ethylene, and Salicylic Acid Signaling on the Rhizosphere Bacterial Community of Arabidopsis thaliana

2011 ◽  
Vol 24 (4) ◽  
pp. 395-407 ◽  
Author(s):  
Rogier F. Doornbos ◽  
Bart P. J. Geraats ◽  
Eiko E. Kuramae ◽  
L. C. Van Loon ◽  
Peter A. H. M. Bakker
Keyword(s):  
Salicylic Acid ◽  
Bacterial Community ◽  
Induced Resistance ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Systemic Resistance ◽  
Culturable Bacteria ◽  
Wild Type ◽  
Defense Signaling ◽  
Rhizosphere Bacterial Community

Systemically induced resistance is a promising strategy to control plant diseases, as it affects numerous pathogens. However, since induced resistance reduces one or both growth and activity of plant pathogens, the indigenous microflora may also be affected by an enhanced defensive state of the plant. The aim of this study was to elucidate how much the bacterial rhizosphere microflora of Arabidopsis is affected by induced systemic resistance (ISR) or systemic acquired resistance (SAR). Therefore, the bacterial microflora of wild-type plants and plants affected in their defense signaling was compared. Additionally, ISR was induced by application of methyl jasmonate and SAR by treatment with salicylic acid or benzothiadiazole. As a comparative model, we also used wild type and ethylene-insensitive tobacco. Some of the Arabidopsis genotypes affected in defense signaling showed altered numbers of culturable bacteria in their rhizospheres; however, effects were dependent on soil type. Effects of plant genotype on rhizosphere bacterial community structure could not be related to plant defense because chemical activation of ISR or SAR had no significant effects on density and structure of the rhizosphere bacterial community. These findings support the notion that control of plant diseases by elicitation of systemic resistance will not significantly affect the resident soil bacterial microflora.

scholarly journals Lack of Induced Systemic Resistance in Peanut to Late Leaf Spot Disease by Plant Growth-Promoting Rhizobacteria and Chemical Elicitors

Plant Disease ◽  
2001 ◽  
Vol 85 (8) ◽  
pp. 879-884 ◽  
Author(s):  
Shouan Zhang ◽  
M. S. Reddy ◽  
Nancy Kokalis-Burelle ◽  
Larry W. Wells ◽  
Stevan P. Nightengale ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Acquired Resistance ◽  
Plant Growth Promoting Rhizobacteria ◽  
Systemic Resistance ◽  
Leaf Spot Disease ◽  
Late Leaf Spot ◽  
Spot Disease ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Significant Disease

A disease assay was optimized for late leaf spot disease of peanut using Cercosporidium per-sonatum in the greenhouse, and this assay was used in attempts to elicit induced systemic resistance using strains of plant growth-promoting rhizobacteria (PGPR) and chemical elicitors. Nineteen strains of spore-forming bacilli PGPR, including strains of Paenibacillus macerans, Brevibacillus brevis, Bacillus laterosporus, B. subtilis, B. pumilus, B. amyloliquefaciens, B. sphaericus, B. cereus, and B. pasteurii, which previously elicited systemic disease control activity on other crops, were evaluated in greenhouse assays. Seven PGPR strains elicited significant disease reduction in a single experiment; however, none repeated significant protection achieved in the greenhouse assay, while significant protection consistently occurred with the fungicide chlorothalonil (Bravo). In other greenhouse trials, neither stem injections of C. personatum nor foliar sprays of chemicals, including salicylic acid, sodium salicylate, isonicotinic acid, or benzo[1,2,3]thiadiazole-7-carbothioc acid S-methyl ester (Actigard), which elicit systemic acquired resistance on other crops, elicited significant disease protection. In contrast, foliar sprays with DL-β-amino-n-butyric acid (BABA), which is an elicitor of localized acquired resistance, resulted in significantly less late leaf spot disease in one of two tests. Combination treatments of four PGPR strains with BABA in the greenhouse did not significantly protect peanut from late leaf spot. Field trials conducted over two growing seasons indicated that none of the 19 PGPR strains, applied as seed treatments at two concentrations, significantly reduced late leaf spot disease. The same chemical elicitors tested in the greenhouse, including BABA, did not elicit significant disease protection. Some combinations of four PGPR and BABA significantly reduced the disease at one but not at two sample times. Collectively, these results suggest that late leaf spot resistance in peanut is not systemically inducible in the same manner as is resistance to diseases in other crops by PGPR and chemical inducers.

scholarly journals 487 Assessment of Chemical Induction of Acquired Resistance to Phytophthora Fruit Rot in Field-grown Pickling Cucumber

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 529A-529
Author(s):  
Priscilla M. Hockin ◽  
Irvin E. Widders
Keyword(s):  
Systemic Acquired Resistance ◽  
Phytophthora Capsici ◽  
Acquired Resistance ◽  
Lesion Size ◽  
Plant Diseases ◽  
Fruit Rot ◽  
Chemical Induction ◽  
Resistance Response ◽  
Chemical Inducers ◽  
Cucumber Fruit

Systemic acquired resistance (SAR) is a physiological defense response in plants conferring broad spectrum resistance to pathogens. SAR is inducible through infection by necrotizing pathogens or chemical inducers and involves the systemic activation of defense related genes. Our objectives were to evaluate resistance expression to phytophthora soft rot fruit in cucumber in response to increasing concentrations of 2,6 dichloroisonicotinic acid (INA) and benzo (1,2,3)thiadiazole-7-carbothioc acid S-methyl ester (BTH) by foliar applications. Excised leaves exhibited a resistance response to foliar applications of all concentrations of INA and BTH tested when challenge inoculated with Colletotrichum lagenarium. There was increasing benefit with increasing concentration of each chemical applied. Harvested cucumber fruit, 3.4 to 4.5 cm in diameter, were challenge inoculated with Phytophthora capsici; there were no significant chemical and rate interactions in terms of internal lesion measurements. Overall, INA consistently reduced lesion size in cucumber fruit. A bioassay conducted on fruit of different maturity levels, as defined by fruit diameter, revealed that larger sized fruit (4 to 5 cm) were more resistant to fruit rot. Fruit with diameters of 3 to 4 cm from plots treated with BTH showed little resistance as compared to the control and fruit from the same treatment with diameters of 2 to 3 cm. Fruit from plots treated with INA had at least 50% reduction in lesion size than the control. It is unclear if these differences were attributable to changes in physiological or anatomical factors. The true importance of these results should be interpreted with caution. Yield studies have not been conducted, and thus, with the experienced stunting, treatment with 100 ppm INA would be expected to lower yield and perhaps fruit quality. Determination of the optimal application regime and other cultural factors will provide broad control of plant diseases.

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