Effects of Methyl Jasmonate on Cylindrocarpon Root Rot Development on Ginseng

Cylindrocarpon root rot, caused by Cylindrocarpon destructans, is a severe disease on ginseng (Panax ginseng C.A. Meyer) in northeast China. Methyl jasmonate (MeJA) has been studied for its ability to induce plant defenses against pathogens. The effects of MeJA on the colony diameter of C. destructans and seedling growth were examined in vitro. Two-year-old ginseng roots were drenched with MeJA (200 mg/L) and then inoculated with conidia suspension of C. destructans (1×106 conidia/ml). Disease severity was assessed on inoculated roots, and the activation of defense responses was also measured. Results showed that MeJA had no effect on the growth of C. destructans and seedlings at low concentrations. The incidence rate and disease severity on MeJA-treated ginseng roots was significantly reduced compared with untreated roots. The proline content was increased but the malondialdehyde (MDA) content decreased in MeJA- treated roots. The activities of phenylalanine amino-lyase (PAL), catalase (CAT), peroxidase (POD) and polyphenoloxidase (PPO) were significantly enhanced in treated roots. It was concluded that low concentrations of MeJA had no effect on C. destructans, but it stimulated the activities of defense enzymes in treated ginseng roots and alleviated the damage of roots from C. destructans. Therefore, the control of Cylindrocarpon root rot by MeJA may involve the activation of the disease-related defense system.

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Antimicrobial Peptides - Small but Mighty Weapons for Plants to Fight Phytopathogens

Protein and Peptide Letters ◽

10.2174/0929866526666190619112438 ◽

2019 ◽

Vol 26 (10) ◽

pp. 720-742 ◽

Cited By ~ 8

Author(s):

Kaushik Das ◽

Karabi Datta ◽

Subhasis Karmakar ◽

Swapan K. Datta

Keyword(s):

Antimicrobial Peptides ◽

Durable Resistance ◽

Defense Responses ◽

Defense System ◽

Biotechnological Potential ◽

Functional Aspects ◽

Low Concentrations ◽

Wide Range ◽

Vital Component ◽

Pathogen Entry

Antimicrobial Peptides (AMPs) have diverse structures, varied modes of actions, and can inhibit the growth of a wide range of pathogens at low concentrations. Plants are constantly under attack by a wide range of phytopathogens causing massive yield losses worldwide. To combat these pathogens, nature has armed plants with a battery of defense responses including Antimicrobial Peptides (AMPs). These peptides form a vital component of the two-tier plant defense system. They are constitutively expressed as part of the pre-existing first line of defense against pathogen entry. When a pathogen overcomes this barrier, it faces the inducible defense system, which responds to specific molecular or effector patterns by launching an arsenal of defense responses including the production of AMPs. This review emphasizes the structural and functional aspects of different plant-derived AMPs, their homology with AMPs from other organisms, and how their biotechnological potential could generate durable resistance in a wide range of crops against different classes of phytopathogens in an environmentally friendly way without phenotypic cost.

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An evaluation of potential seed treatments to control Fusarium solani f.sp. phaseoli, the cause of foot and root rot of Phaseolus vulgaris

The Journal of Agricultural Science ◽

10.1017/s0021859600027428 ◽

1977 ◽

Vol 89 (1) ◽

pp. 235-238 ◽

Cited By ~ 5

Author(s):

P. E. Russell ◽

A. E. A. Mussa

Keyword(s):

Phaseolus Vulgaris ◽

Fusarium Solani ◽

Root Rot ◽

Similar Pattern ◽

Fungal Growth ◽

Systemic Fungicide ◽

Product Concentration ◽

Low Concentrations ◽

High Concentrations

SummaryTwo systemic fungicides, benomyl and thiabendazole, were more active than the non-systemic fungicide Drazoxolon in inhibiting fungal growth in vitro. A similar pattern was obtained in glasshouse trials with benomyl and thiabendazole giving adequate protection at low concentrations while Drazoxolon was ineffective unless applied at 50% the commercial product concentration. A field trial using thiabendazole, Drazoxolon and a mixture of benomyl and thiram confirmed the glasshouse results.Some phytotoxicity was noticed with high concentrations of both benomyl and thiabendazole, but satisfactory disease control was achieved using fungicide concentrations which did not induce phytotoxicity.

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Pathogenicity of Fusarium species associated with crown and root rot of wheat (Triticum aestivum) under different condition

Innovaciencia Facultad de Ciencias Exactas Físicas y Naturales ◽

10.15649/2346075x.659 ◽

2019 ◽

Vol 7 (1) ◽

pp. 1-9

Author(s):

Bareen Sidqi Shareef Al-Tovi ◽

Raed Abduljabbar Haleem

Keyword(s):

Disease Severity ◽

Root Rot ◽

Field Experiments ◽

Fusarium Species ◽

Test Tube ◽

Spore Suspension ◽

Wheat Crop ◽

Pathogenicity Test ◽

Crown And Root Rot

This study was conducted to test the pathogenicity of Fusarium species, the causes of crown and root rot disease of wheat crop, under three different conditions (Laboratory, Greenhouse and Field) and to show the best method for pathogenicity among different conditions. Pathogenicity test of six isolates of Fusarium species (F. graminearum, F. oxysporum, F. avenaceum, F. nivale, F. solani and F. udum) was tested on durum (Simeto) cultivar of wheat by test tube method in the laboratory, the tested fungi had substantial effect on seed germination. F. oxysporum showed the highest germination failure (44.44%) which significantly differed with other species. In the greenhouse, seedlings were inoculated by spore suspension at the base of each plant stem. The most virulent fungus after 35 days of inoculation was F. oxysporum (0.78) followed by F. solani (0.70) and F. graminearum (0.66), while the lowest disease severity was recorded by F. udum (0.16). Also in the field pathogenicity experiments of three Fusarium species (F. graminearum, F. oxysporum and F. solani) were performed on a durum (Simeto) and soft (Cham6) cultivars. Spore suspension was applied at the 2- to 3-leaf Zadoks’s growth stage. Disease severity was calculated at two stages of wheat growth (Booting and Ripening).The most virulent fungus was F. graminearum (0.42) that was significantly different from other fungi. This work indicated that F. graminearum, F. oxysporum and F. solani showed higher infection than remaining tested species under threeconditions. Pathogenicity test in laboratory by test tube method (In-vitro) appeared more effective than greenhouse and field experiments

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Phytophthora Root Rot of Blueberry Increases with Frequency of Flooding

HortScience ◽

10.21273/hortsci.34.4.693 ◽

1999 ◽

Vol 34 (4) ◽

pp. 693-695 ◽

Cited By ~ 2

Author(s):

Amal de Silva ◽

Keith Patterson ◽

Craig Rothrock ◽

Ron McNew

Keyword(s):

Disease Severity ◽

Root Rot ◽

Phytophthora Cinnamomi ◽

Disease Incidence ◽

Severe Disease ◽

Vaccinium Corymbosum ◽

Root Infection ◽

Phytophthora Root Rot ◽

Severity Rating ◽

Linear Relationships

Phytophthora root rot is a severe disease on blueberry (Vaccinium corymbosum L.) in poorly drained soils. Little is known about how mulching and frequent waterlogging affect disease severity in blueberries. Phytophthora cinnamomi Rands was grown on rice hulls, which were incorporated into the soil at the rate of 10% (v:v). Waterlogging conditions were imposed for 48 hours 1 week after planting on mulched and nonmulched blueberry plants at weekly, biweekly, and monthly intervals for a total of 3 months. Control plants were not subjected to flooding. The severity of Phytophthora root rot increased with time. Significant linear relationships were found between flooding interval and disease severity rating of shoot, percentage of root infection, and shoot and root dry weights of plants. Disease symptoms were minimal in control plants, but shoot disease rating and percentage of root infection were high in mulched and nonmulched plants that were flooded every week. Shoot and root dry weights were higher in 1997 than in 1996. In 1996, mulched plants had higher shoot dry weights than did nonmulched plants. Disease incidence was higher with weekly and biweekly flooding than with monthly or no flooding. However, mulching did not affect root infection.

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Influence of Glyphosate on Rhizoctonia Crown and Root Rot (Rhizoctonia solani) in Glyphosate-Resistant Sugarbeet

Weed Science ◽

10.1614/ws-d-11-00027.1 ◽

2012 ◽

Vol 60 (1) ◽

pp. 113-120 ◽

Cited By ~ 7

Author(s):

Kelly A. Barnett ◽

Christy L. Sprague ◽

William W. Kirk ◽

Linda E. Hanson

Keyword(s):

Rhizoctonia Solani ◽

Ammonium Sulfate ◽

Disease Severity ◽

Root Rot ◽

Radial Growth ◽

Field Experiments ◽

Herbicide Treatments ◽

Tolerant Variety ◽

Crown And Root Rot

Previous greenhouse studies with a noncommercial glyphosate-resistant sugarbeet variety indicated that susceptibility to Rhizoctonia crown and root rot could increase after glyphosate was applied. Greenhouse and field experiments were conducted in 2008 and 2009 to determine if glyphosate influenced disease severity in potential commercially available varieties of glyphosate-resistant sugarbeet. In the first greenhouse experiment in 2008, Hilleshög 9027RR, the most tolerant variety to Rhizoctonia crown and root rot, exhibited an increase in disease severity when glyphosate was applied. There were no significant differences between herbicide treatments in Hilleshög 9028RR, and glyphosate decreased disease severity in Hilleshög 9032RR when compared with the no-herbicide treatment. Experiments conducted to determine if glyphosate influenced Rhizoctonia solani growth in vitro indicated that glyphosate did not increase the radial growth of R. solani, except at 10× (190 µg ae ml−1) the normal rate of glyphosate plus ammonium sulfate (AMS). Field and additional greenhouse experiments were conducted using four commercial varieties. Differences in disease severity were observed when comparing varieties, but glyphosate did not significantly influence the severity of Rhizoctonia crown and root rot when compared with the no-herbicide control. Choosing a glyphosate-resistant sugarbeet variety with the best demonstrated tolerance to Rhizoctonia crown and root rot is an important factor in reducing disease severity and maintaining sugarbeet yield.

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Effects of Salicylic Acid and Methyl Jasmonate Treatments on Flavonoid and Carotenoid Accumulation in the Juice Sacs of Satsuma Mandarin In Vitro

Applied Sciences ◽

10.3390/app10248916 ◽

2020 ◽

Vol 10 (24) ◽

pp. 8916

Author(s):

Risa Yamamoto ◽

Gang Ma ◽

Lancui Zhang ◽

Miki Hirai ◽

Masaki Yahata ◽

...

Keyword(s):

Salicylic Acid ◽

Methyl Jasmonate ◽

Citrus Fruit ◽

Defense Responses ◽

Transcriptional Level ◽

Carotenoid Accumulation ◽

Satsuma Mandarin ◽

Meja Treatment ◽

Juice Sacs

Salicylic acid and jasmonic acid are two important plant hormones that trigger the plant defense responses and regulate the accumulation of bioactive compounds in plants. In the present study, the effects of salicylic acid (SA) and methyl jasmonate (MeJA) on flavonoid and carotenoid accumulation were investigated in the juice sacs of Satsuma mandarin in vitro. The results showed that SA treatment was effective to enhance the contents of eriocitrin, narirutin, poncirin, and β-cryptoxanthin in the juice sacs (p < 0.05). In contrast, the MeJA treatment inhibited flavonoid and carotenoid accumulation in the juice sacs (p < 0.05). Gene expression results showed that the changes of flavonoid and carotenoid contents in the SA and MeJA treatments were highly regulated at the transcriptional level. In addition, a transcriptional factor CitWRKY70 was identified in the microarray analysis, which was induced by the SA treatment, while suppressed by the MeJA treatment. In the SA and MeJA treatments, the change in the expression of CitWRKY70 was consistent with that of flavonoid and carotenoid biosynthetic key genes. These results indicated that CitWRKY70 might be involved in the regulation of flavonoid and carotenoid accumulation in response to SA and MeJA treatments in the juice sacs of citrus fruit.

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Potential of Bacillus subtilis for controlling bacterial leaf blight pathogen in rice

Food Research ◽

10.26656/fr.2017.4(s5).011 ◽

2020 ◽

Vol 4 (S5) ◽

pp. 124-130

Author(s):

K.S. Ku Asmah ◽

Z. Sapak

Keyword(s):

Bacillus Subtilis ◽

Disease Severity ◽

Severe Disease ◽

Severity Index ◽

Leaf Blight ◽

Bacterial Leaf Blight ◽

In Vivo Studies ◽

Disease Severity Index ◽

Rice Plants

Bacterial leaf blight (BLB) of rice is an economically important disease caused by Xanthomonas oryzae pv. oryzae (Xoo) throughout the world. To control this disease, bacterial isolate of Bacillus subtilis UiTMB1 was screened for the antagonistic activity against the pathogen in vitro and in vivo studies. A bacterial assay and detached leaf technique were used to evaluate the potential of the bacterium against BLB pathogen in the laboratory. Meanwhile, the glasshouse study was conducted to further examine the aptitudes of the isolate on the disease control and growth-promoting of rice plants. The findings revealed that B. subtilis UiTMB1 is able to control the disease and enhance the growth of rice plants. Rice plants treated with B. subtilis UiTMB1 before being inoculated with BLB pathogen showed less severe disease symptoms with low disease severity index of 3.43 compared to rice plants without B. subtilis UiTMB1 with high disease severity index of 8.4. Besides controlling the disease, B. subtilis UiTMB1 was also promoting plant height, chlorophyll content, number of tillers and biomass of rice plants.

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Longitudinal characterization of circulating neutrophils uncovers distinct phenotypes associated with disease severity in hospitalized COVID-19 patients

10.1101/2021.10.04.463121 ◽

2021 ◽

Author(s):

Thomas J. LaSalle ◽

Anna L. K. Gonye ◽

Samuel S. Freeman ◽

Paulina Kaplonek ◽

Irena Gushterova ◽

...

Keyword(s):

Disease Severity ◽

Severe Disease ◽

Gene Expression Signature ◽

Suppressor Cell ◽

Gene Signature ◽

Neutrophil Extracellular Trap ◽

Effector Functions ◽

Neutrophil Degranulation ◽

Mechanistic Basis

Multiple studies have identified an association between neutrophils and COVID-19 disease severity; however, the mechanistic basis of this association remains incompletely understood. Here we collected 781 longitudinal blood samples from 306 hospitalized COVID-19+ patients, 78 COVID-19- acute respiratory distress syndrome patients, and 8 healthy controls, and performed bulk RNA-sequencing of enriched neutrophils, plasma proteomics, cfDNA measurements and high throughput antibody profiling assays to investigate the relationship between neutrophil states and disease severity or death. We identified dynamic switches between six distinct neutrophil subtypes using non-negative matrix factorization (NMF) clustering. At days 3 and 7 post-hospitalization, patients with severe disease had an enrichment of a granulocytic myeloid derived suppressor cell-like state gene expression signature, while non-severe patients with resolved disease were enriched for a progenitor-like immature neutrophil state signature. Severe disease was associated with gene sets related to neutrophil degranulation, neutrophil extracellular trap (NET) signatures, distinct metabolic signatures, and enhanced neutrophil activation and generation of reactive oxygen species (ROS). We found that the majority of patients had a transient interferon-stimulated gene signature upon presentation to the emergency department (ED) defined here as Day 0, regardless of disease severity, which persisted only in patients who subsequently died. Humoral responses were identified as potential drivers of neutrophil effector functions, as enhanced antibody-dependent neutrophil phagocytosis and reduced NETosis was associated with elevated SARS-CoV-2-specific IgG1-to-IgA1 ratios in plasma of severe patients who survived. In vitro experiments confirmed that while patient-derived IgG antibodies mostly drove neutrophil phagocytosis and ROS production in healthy donor neutrophils, patient-derived IgA antibodies induced a predominant NETosis response. Overall, our study demonstrates neutrophil dysregulation in severe COVID-19 and a potential role for IgA-dominant responses in driving neutrophil effector functions in severe disease and mortality.

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Effect of Methyl Jasmonate and Salicylic Acid on In Vitro Growth, Stevioside Production, and Oxidative Defense System in Stevia rebaudiana

Sugar Tech ◽

10.1007/s12355-019-00727-8 ◽

2019 ◽

Vol 21 (6) ◽

pp. 1031-1038 ◽

Cited By ~ 6

Author(s):

Sajjad Moharramnejad ◽

Amirali Taheri Azam ◽

Jaber Panahandeh ◽

Zahra Dehghanian ◽

Muhammad Ashraf

Keyword(s):

Salicylic Acid ◽

Methyl Jasmonate ◽

Stevia Rebaudiana ◽

In Vitro Growth ◽

Defense System ◽

Oxidative Defense

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Relationship between in vitro growth inhibition of pathogens and suppression of preemergence damping-off and postemergence root rot of white bean seedlings in the greenhouse by bacteria

Canadian Journal of Microbiology ◽

10.1139/m94-018 ◽

1994 ◽

Vol 40 (2) ◽

pp. 113-119 ◽

Cited By ~ 34

Author(s):

M. S. Reddy ◽

R. K. Hynes ◽

G. Lazarovits

Keyword(s):

Rhizoctonia Solani ◽

Disease Severity ◽

Fusarium Solani ◽

Root Rot ◽

Culture Media ◽

Pythium Ultimum ◽

Damping Off ◽

Bacterial Strains ◽

White Bean

One hundred and twenty diverse bacterial strains were screened under greenhouse conditions for their ability to protect white bean seedlings from preemergence damping-off caused by Pythium ultimum and Rhizoctonia solani and postemergence root rot by Fusarium solani f.sp. phaseoli. Preemergence mortality or root rot increased with an increase in the inoculum concentration of fungal isolates. For further testing, 200 propagules/g soil of P. ultimum, 3 propagules/g soil of R. solani, and log 3 conidia/g vermiculite of F. solani f.sp. phaseoli were used, as these rates provided an optimal level (approximately 50%) of disease severity. Bacterial strains suspended in sterile distilled water were added to pathogen-amended soil or vermiculite at log 7 colony-forming units/g soil or vermiculite prior to seeding. Final healthy stand and root rot were recorded 4 weeks after planting. Nine bacterial strains on P. ultimum, five on R. solani, and nine on F. solani f.sp. phaseoli provided significant (P = 0.05) suppression of disease severity compared with the nonbacterized control. Bacterial strains were also tested in vitro against the mycelial growth of the fungi on solid and liquid media. There was no relationship between the ability of bacterial strains to inhibit fungal vegetative growth on solid culture media and their ability to suppress pathogen activity in the greenhouse, but, for a few strains, the reduction in disease was linked to reduced growth of the pathogens in liquid media.Key words: White bean, damping-off, root rot, Pythium ultimum, Rhizoctonia solani, Fusarium solani f.sp. phaseoli.

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