scholarly journals Two pathogenesis-related proteins interact with leucine-rich repeat proteins to promote Alternaria leaf spot resistance in apple

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Qiulei Zhang ◽  
Chaoran Xu ◽  
Haiyang Wei ◽  
Wenqi Fan ◽  
Tianzhong Li
Keyword(s):  
Leaf Spot ◽  
Coiled Coil ◽  
Fungal Growth ◽  
Pr Proteins ◽  
Bimolecular Fluorescence Complementation ◽  
Economic Losses ◽  
Leucine Rich Repeat ◽  
Fungal Disease Resistance ◽  
Pathogenesis Related

AbstractAlternaria leaf spot in apple (Malus x domestica), caused by the fungal pathogen Alternaria alternata f. sp. mali (also called A. mali), is a devastating disease resulting in substantial economic losses. We previously established that the resistance (R) protein MdRNL2, containing a coiled-coil, nucleotide-binding, and leucine-rich repeat (CCR-NB-LRR) domain, interacts with another CCR-NB-LRR protein, MdRNL6, to form a MdRNL2–MdRNL6 complex that confers resistance to A. mali. Here, to investigate the function of the MdRNL2–MdRNL6 complex, we identified two novel pathogenesis-related (PR) proteins, MdPR10-1 and MdPR10-2, that interact with MdRNL2. Yeast two-hybrid (Y2H) assays and bimolecular fluorescence complementation (BiFC) assays confirmed that MdPR10-1 and MdPR10-2 interact with MdRNL2 and MdRNL6 at the leucine-rich repeat domain. Transient expression assays demonstrated that accumulation of MdPR10-1 and MdPR10-2 enhanced the resistance of apple to four strains of A. mali that we tested: ALT1, GBYB2, BXSB5, and BXSB7. In vitro antifungal activity assays demonstrated that both the proteins contribute to Alternaria leaf spot resistance by inhibiting fungal growth. Our data provide evidence for a novel regulatory mechanism in which MdRNL2 and MdRNL6 interact with MdPR10-1 and MdPR10-2 to inhibit fungal growth, thereby contributing to Alternaria leaf spot resistance in apple. The identification of these two novel PR proteins will facilitate breeding for fungal disease resistance in apple.

scholarly journals Fungicide Sensitivity Monitoring of Alternaria spp. Causing Leaf Spot of Sugarbeet (Beta vulgaris) in the Upper Great Lakes

Plant Disease ◽  
2019 ◽  
Vol 103 (9) ◽  
pp. 2263-2270 ◽  
Author(s):  
N. Rosenzweig ◽  
L. E. Hanson ◽  
S. Mambetova ◽  
Q. W. Jiang ◽  
C. Guza ◽  
...  
Keyword(s):  
Disease Management ◽  
Leaf Spot ◽  
Resistance Management ◽  
Fungal Growth ◽  
The United States ◽  
Cross Resistance ◽  
Management Approach ◽  
Dilution Method ◽  
Fungicide Sensitivity

Alternaria leaf spot (ALS), caused by Alternaria spp., can occur wherever sugarbeet is grown. Infection by Alternaria spp. and disease management has historically been considered a minor issue in sugarbeet production in the United States. An increase of both incidence and severity in 2016 of ALS high enough to cause yield loss has been observed in Michigan. With a renewed need to consider potential management of this disease, the sensitivity was determined for populations of Alternaria spp. to three classes of fungicides currently labeled for management of leaf spot on sugarbeet, including demethylase inhibitor (DMI), quinone outside inhibitor (QoI), and organo-tin fungicides. Leaves with symptoms of ALS were sampled from sugarbeet fields in east-central Michigan and southwestern Ontario, Canada. Monoconidial isolates were obtained to determine sensitivity to each fungicide class above. A spiral gradient dilution method was used to estimate the fungicide effective concentration (in milligrams per liter) that caused a 50% inhibition of fungal growth in vitro for all isolates. Significant temporal shifts were detected in the frequencies of sensitivity phenotypes to DMI and QoI but not organo-tin fungicides from 2016 through 2017. Individual isolates of Alternaria spp. were recovered with cross-resistance to DMI and multiple resistance to DMI, QoI, and triphenyltin hydroxide fungicides. To our knowledge, this is the first report of a fungus other than Cercospora beticola with resistance to organo-tin fungicides. Fungicide sensitivity monitoring indicates that an effective integrated disease management approach combining fungicide efficacy trials and monitoring pathogen biology is essential for developing effective resistance management recommendations.

scholarly journals Pestalotiopsis desseminata PADA JAMBU MENTE BIOLOGI DAN INTERAKSINYA DENGAN Helopeltis antonii

2020 ◽  
Vol 6 (3) ◽  
pp. 66
Author(s):  
ESTHER M. ADHI ◽  
SUPRIADI SUPRIADI ◽  
S. RAHAYUNINGSIH ◽  
D. KILIN ◽  
NURI KARYANI
Keyword(s):  
Leaf Spot ◽  
Mycelial Growth ◽  
Agar Medium ◽  
Fungal Growth ◽  
Pathogenicity Test ◽  
Leaf Spots ◽  
Fungal Biology ◽  
Mycelia Growth ◽  
Medicinal Crops

<p><strong>Pestalotiopsis desseminata on cashew: its biology and interaction with Helopeltis antonii</strong></p><p>Pestalotiopsis desseminata is one of pathogens causing leaf spots. die-back of shoots and inflorescence of cashew plant. It is assumed there is an interaction between the attack of Helopeltis antonii and the fungus in Ihe ield so that the damage becomes more devastating. The objectives of (his research were to investigate several aspects of fungal biology (pathogenicity, mycelial growth, acervuli production, sensitivity to fungicides) and its interaction with //. antonii. The esearch was carried out from April 1999 to March 2000 at the laboratory and green house of Pest and Disease Department Research Institute for Spice and Medicinal Crops, Bogor. /' desseminata was diectly isolated from cashew leaves. Pathogenicity test of P. desseminata isolate was conducted on cashew seedlings. The fungal growth and fungicide effects were carried out in vitro on agar medium. The interaction between P. desseminata and H. antonii was examined by inoculating the fungus and insect, either individually or in combination, on cashew seedlings. The results showed that P. desseminata isolate fomis black spherical acervuli containing oblongs conidia with 5 cells, and the outermost cell has 3 flagellate. Acervuli could only be produced on the cultue illuminated continuously by 600 lux translucent lamp. Pathogenicity test of several isolates of /' desseminata on cashew seedlings caused spherical leaf spot symptom, individually or coalesced as bigger leaf spots. In vitro fungal mycelia growth could be suppressed by several fungicides, including bcnomyl 50% (I ppm) and Uiiopanate-mcthyl 70% (10 ppm) Combining inoculation between P. desseminata and //. antonii resulted in moe severe (devastating) die-back compared with individually inoculated.</p>

scholarly journals Towards Biological Control of Aspergillus carbonarius and Botrytis cinerea in Grapevine Berries and Transcriptomic Changes of Genes Encoding Pathogenesis-Related (PR) Proteins

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 970
Author(s):  
Danai Gkizi ◽  
Eirini G. Poulaki ◽  
Sotirios E. Tjamos
Keyword(s):  
Biological Control ◽  
Botrytis Cinerea ◽  
Defense Responses ◽  
Economic Losses ◽  
Aspergillus Carbonarius ◽  
In Vitro Experiments ◽  
In Planta ◽  
Pathogenesis Related ◽  
Genes Encoding

Grapevine bunch rot, caused by Botrytis cinerea and Aspergillus carbonarius, causes important economic losses every year in grape production. In the present study, we examined the plant protective activity of the biological control agents, Paenibacillus alvei K165, Blastobotrys sp. FP12 and Arthrobacter sp. FP15 against B. cinerea and A. carbonarius on grapes. The in vitro experiments showed that strain K165 significantly reduced the growth of both fungi, while FP15 restricted the growth of A. carbonarius and FP12 was ineffective. Following the in vitro experiments, we conducted in planta experiments on grape berries. It was shown that K165, FP12 and FP15 reduced A. carbonarius rot severity by 81%, 57% and 37%, respectively, compared to the control, whereas, in the case of B. cinerea, the only protective treatment was that with K165, which reduced rot by 75%. The transcriptomic analysis of the genes encoding the pathogenesis-related proteins PR2, PR3, PR4 and PR5 indicates the activation of multiple defense responses involved in the biocontrol activity of the examined biocontrol agents.

scholarly journals Effect of different culture media on growth characteristics of Cercospora beticola sacc, causing cercospora leaf spot of beetroot

2021 ◽  
Vol 16 (1) ◽  
pp. 64-66
Author(s):  
Kandhi Mounika ◽  
Abhilasha A. Lal
Keyword(s):  
Leaf Spot ◽  
Culture Media ◽  
Fungal Growth ◽  
Potato Dextrose Agar ◽  
Cercospora Beticola ◽  
Cercospora Leaf Spot ◽  
Agar Media ◽  
Cultural Media ◽  
Growth Characters

Beetroot (Beta vulgaris L.) is a versatile crop; it can be grown in any season. It is also known as table beet, garden beet, and sugar beet. Beetroot crop is affected by number of fungal diseases. Cercospora leaf spot is the most devastating foliar disease caused by Cercospora beticola. Fungi grow on diverse habitat; it requires different specific elements for their growth and development in in vitro. In the present investigation three different culture media viz., Beetroot leaf extract agar media, Richards’s agar media, and Potato dextrose agar media were tested against cercospora beticola to evaluate the effect of different culture media on growth characters of Cercospora beticola. The fungi showed difference in growth development when grown on different cultural media. Results obtained that the best fungal growth was observed in Richard’s agar media and the minimum growth was observed in potato dextrose agar media.

scholarly journals Role of botanical plant extracts to control plant pathogens

2018 ◽  
Author(s):  
Debjani Choudhury ◽  
Prerna Dobhal ◽  
Seweta Srivastava ◽  
Soumen Saha and Susamoy Kundu
Keyword(s):  
Plant Extracts ◽  
Plant Pathogens ◽  
Control Plant ◽  
Fungal Growth ◽  
Economic Losses ◽  
Sulphur Compounds ◽  
Horticultural Crops ◽  
Development Of Resistance ◽  
Synthetic Chemicals

Agricultural and horticultural crops are spoiled by various fungi causing economic losses, and health risk to the consumers due to mycotoxins produced by fungi. The indiscriminate use of synthetic chemicals led to development of resistance in plants which has necessitated utilization of higher concentrations, with the consequent rise in toxicity in food products. In ecosystem plants are surrounded by various enemies which defend themselves by producing secondary metabolites like terpenes, phenols and nitrogen and sulphur compounds. A new approach to control the pathogens which hampers quality food production has been implemented by the application of plant extract. Various studies have explained that plant extracts contain sundry of bioactive components that can control the fungal growth. The aim of this article is to summarize the results of in vitro experiments from the various literatures regarding the effects of plant-derived compounds for controlling growth of fungi.

scholarly journals First Report of Cladosporium Leaf Spot of Spinach Caused by Cladosporium variabile in North Carolina

Plant Disease ◽  
2014 ◽  
Vol 98 (12) ◽  
pp. 1741-1741
Author(s):  
A. C. Scruggs ◽  
S. C. Butler ◽  
L. M. Quesada-Ocampo
Keyword(s):  
North Carolina ◽  
Leaf Spot ◽  
Fungal Growth ◽  
The United States ◽  
Hot Water ◽  
Economic Losses ◽  
Fluorescent Light ◽  
Single Spore ◽  
First Report ◽  
Infected Seed

Cladosporium leaf spot of spinach, caused by Cladosporium variabile, can result in significant economic losses in the United States (2). In March 2014, symptoms consistent with Cladosporium leaf spot (4) appeared on the spinach cultivar Tyee in a greenhouse located in Rowan County, NC. Of 1,080 spinach plants, 90 to 100% were infected. Symptoms consisted of small (1 to 3 mm in diameter), circular, tan lesions each outlined with a dark margin on the adaxial surface of the leaf. On severely infected foliage, lesions coalesced to produce relatively large necrotic regions. Profuse fungal sporulation was observed on the lesion surface with a dissecting microscope at 40× magnification. Using a dissecting microscope, conidia were collected with a sterile needle and transferred to petri plates containing potato dextrose agar. Plates were then incubated at 23 ± 2°C under continuous fluorescent light, and fungal growth was apparent after 24 h. Isolations from leaves of six infected plants produced slow-growing, dark green to brown fungal colonies that reached only 31 mm in diameter after 14 days, which is characteristic of C. variabile (4). Colonies contained dense masses of dematiaceous, septate, unbranched conidiophores with conidial chains, each containing up to five conidia. Conidia were ovate to elongate, with some being septate. The length of individual conidia ranged from 10 to 19 μm. Conidial septa were distinctly dark when observed at 100× magnification, which is a defining feature of C. variabile vs. the conidia of C. macrocarpum (4). The surface of the conidia appeared verrucose at 100× magnification, and conidia were each distinctly darkened toward the base. A single isolate obtained through single-spore transfer was used for DNA extraction, and the histone 3 (H3) gene sequence was amplified using the primers CYLH3F and CYLH3R (1). Sequence analysis of the amplified product using BLAST analysis indicated that the H3 sequences had 100% identity to that of a C. variabile isolate (GenBank Accession No. EF679710.1), and 99% identity to a C. macrocarpum isolate (EF679687.1). The H3 sequence from a representative isolate was deposited in GenBank (KJ769146). To our knowledge, this is the first report of Cladosporium leaf spot on spinach in North Carolina based on morphological evaluation and H3 sequencing results. C. variabile is a seedborne pathogen, so it is possible inoculum was introduced into the greenhouses in North Carolina on infected seed (3). Seeds can be treated with hot water or chlorine to reduce the risk of disease outbreaks caused by infected seed (2). Furthermore, Cladosporium leaf spot may be controlled with the use of fungicides (3). References: (1) P. Crous et al. Stud. Mycol. 50:415, 2004. (2) L. J. du Toit and P. Hernandez-Perez. Plant Dis. 89:1305, 2005. (3) L. J. du Toit et al. Fung. Nemat. Tests 59:V115, 2004. (4) Schubert et al. Stud. Mycol. 58:105, 2007.

scholarly journals Alternative methods for angular stain control in mangoes (Mangifera indica L.)

2021 ◽  
Vol 10 (17) ◽  
pp. e11101724118
Author(s):  
Mirelle Ribeiro Araújo ◽  
Geovanka Marcelle Aguiar Leão ◽  
Eskálath Morganna Silva Ferreira ◽  
Raphael Sanzio Pimenta ◽  
Joenes Mucci Peluzio ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Xanthomonas Campestris ◽  
Mangifera Indica ◽  
Inhibitory Effect ◽  
Significant Inhibition ◽  
Angular Leaf Spot ◽  
Alternative Methods ◽  
Economic Losses ◽  
Mauritia Flexuosa

The conventional methods used for angular stain control are generally chemical methods, however the use of these products can cause high environmental impact and damage to consumer health if it is used in large quantities and undiluted and applied correctly. Based on this problem, this work aimed to evaluate in vitro alternative forms of control using Saccharomyces yeast (with probiotic potential), ethanolic extracts of Mauritia flexuosa (Buriti) and Miconia albicans (Cinnamon-old) plants. To evaluate four GRAS substances in angular leaf spot control caused by Xanthomonas campestris pv. Mangifera indica, during the postharvest period in mangoes. In vitro results using antagonist yeasts showed no inhibitory effect against X. campestris. However, the extracts of the plants Miconia albicans and Mauritia flexuosa showed a significant inhibition. Thus, as two GRAS substances, 1%, 1.5% and 3% sodium carbonate and 3% sodium bicarbonate inhibited X. campestris growth 100%. Given the results obtained, the plant extracts and the GRAS substances tested were effective in controlling phytobacteria and proved to be an alternative in controlling angular leaf spot, thus avoiding economic losses during the mango postharvest phase.

scholarly journals Apoplastic Extracts from a Transgenic Wheat Line Exhibiting Lesion-Mimic Phenotype Have Multiple Pathogenesis-Related Proteins That Are Antifungal

2004 ◽  
Vol 17 (12) ◽  
pp. 1306-1317 ◽  
Author(s):  
Ajith Anand ◽  
Zhentian Lei ◽  
Lloyd W. Sumner ◽  
Kirankumar S. Mysore ◽  
Yasuyuki Arakane ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Inhibitory Activity ◽  
Transgenic Wheat ◽  
Pr Proteins ◽  
Gaeumannomyces Graminis ◽  
Wheat Line ◽  
Head Blight ◽  
Lesion Mimic ◽  
Pathogenesis Related

A transgenic wheat line constitutively expressing genes encoding a class IV acidic chitinase and an acidic β-1,3-glucanase, showed significant delay in spread of Fusarium head blight (scab) disease under greenhouse conditions. In an earlier work, we observed a lesion-mimic phenotype in this transgenic line when homozygous for transgene loci. Apoplastic fluid (AF) extracted from the lesion-mimic plants had pathogenesis-related (PR) proteins belonging to families of β-1,3-glucanases, chitinases, and thaumatin-like proteins (TLPs). AF had growth inhibitory activity against certain fungal pathogens, including Fusarium graminearum and Gaeumannomyces graminis var. tritici. Through a two-step ion-exchange chromatography protocol, we recovered many PR proteins and a few uncharacterized proteins. Three individual protein bands corresponding to a TLP (molecular mass, 16 kDa) and two β-1,3-glucanases (molecular mass, 32 kDa each) were purified and identified by tandem mass spectrometry. We measured the in vitro antifungal activity of the three purified enzymes and a barley class II chitinase (purified earlier in our laboratory) in microtiter plate assays with macroconidia or conidiophores of F. graminearum and Pyrenophora tritici-repentis. Mixtures of proteins revealed synergistic or additive inhibitory activity against F. graminearum and P. tritici-repentis hyphae. The concentrations of PR proteins at which these effects were observed are likely to be those reached in AF of cells exhibiting a hypersensitive response. Our results suggest that apoplastic PR proteins are antifungal and their antimicrobial potency is dependent on concentrations and combinations that are effectively reached in plants following microbial attack.

Vibrio harveyi virulence gene expression in vitro and in vivo during infection in black tiger shrimp Penaeus monodon

2020 ◽  
Vol 139 ◽  
pp. 153-160
Author(s):  
S Peeralil ◽  
TC Joseph ◽  
V Murugadas ◽  
PG Akhilnath ◽  
VN Sreejith ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Genes ◽  
Vibrio Harveyi ◽  
Penaeus Monodon ◽  
Challenge Test ◽  
Virulence Gene ◽  
Economic Losses ◽  
Virulence Gene Expression

Luminescent Vibrio harveyi is common in sea and estuarine waters. It produces several virulence factors and negatively affects larval penaeid shrimp in hatcheries, resulting in severe economic losses to shrimp aquaculture. Although V. harveyi is an important pathogen of shrimp, its pathogenicity mechanisms have yet to be completely elucidated. In the present study, isolates of V. harveyi were isolated and characterized from diseased Penaeus monodon postlarvae from hatcheries in Kerala, India, from September to December 2016. All 23 tested isolates were positive for lipase, phospholipase, caseinase, gelatinase and chitinase activity, and 3 of the isolates (MFB32, MFB71 and MFB68) showed potential for significant biofilm formation. Based on the presence of virulence genes, the isolates of V. harveyi were grouped into 6 genotypes, predominated by vhpA+ flaB+ ser+ vhh1- luxR+ vopD- vcrD+ vscN-. One isolate from each genotype was randomly selected for in vivo virulence experiments, and the LD50 ranged from 1.7 ± 0.5 × 103 to 4.1 ± 0.1 × 105 CFU ml-1. The expression of genes during the infection in postlarvae was high in 2 of the isolates (MFB12 and MFB32), consistent with the result of the challenge test. However, in MFB19, even though all genes tested were present, their expression level was very low and likely contributed to its lack of virulence. Because of the significant variation in gene expression, the presence of virulence genes alone cannot be used as a marker for pathogenicity of V. harveyi.

In-Vitro Effects of Ricinus Communis Seed Kernel Extract On Some Antioxidant And Hydrolytic Enzymes In Nymph And Adult Zonocerus Variegatus (Grasshopper)

2019 ◽  
Vol 3 (1) ◽  
pp. 129-137
Author(s):  
Gbadebo E . Adeleke ◽  
Olaniyi T. Adedosu ◽  
Rachael O. Adeyi ◽  
John O. Fatoki
Keyword(s):  
Ricinus Communis ◽  
Hydrolytic Enzymes ◽  
Crude Enzyme ◽  
Economic Losses ◽  
Seed Kernel ◽  
Zonocerus Variegatus ◽  
Sod Activity ◽  
Enzyme Preparations ◽  
In Vitro Effects

Background: Many plants have been identified for their insecticidal properties as alternatives to synthetic ones, which are toxic to untargeted organisms and environment. Ricinus communis (Castor) has been re-ported to exhibit insecticidal properties against insect pests. Zonocerus variegatus (Grasshopper) is a notable pest of several crops, and has been linked with great economic losses to farmers. The present study investigates the in-vitro toxicity of R. communis seed kernel extract (RCSKE) on the activities of selected antioxidant and hydrolytic enzymes in nymph and adult Zonocerus variegatus (Grasshopper), using cypermethrin (CYPER-M) and chlorpyrifos (CPF) as standard conventional pesticides. Methods: Seed kernel of Ricinus communis (Castor) was subjected to acidified aqueous extraction to obtain the extract (RCSKE). Crude enzyme preparations were obtained from nymph and adult Z. variegatus grass-hoppers. The in-vitro effects of different concentrations (15, 30, 45, 60, 75, 90 and 105μg/ml) each of RCSKE, CYPER-M and CPF on the activities of superoxide dismutase (SOD), catalase (CAT), acetylcholinesterase (AChE) and carboxylesterase (CES) in crude enzyme preparations were estimated spectrophotometrically. The level of statistical significance was 0.05. Results: The RCSKE significantly reduced the in-vitro SOD activity (p < 0.05) in nymph Z. variegatus at all the concentrations, whereas both CYPER-M and CPF significantly reduced the activity only at certain concentrations. The CAT activity in the nymph was significantly decreased by RCSKE and CPF at all the concentrations, but CYPER-M decreased it only at certain concentrations. In adult Z. variegatus, SOD activity was not significantly affected (p > 0.05), while CAT activity was significantly increased (p < 0.05) by the three agents at all the concentrations. The AChE and CES activities in the nymph were significantly reduced by RCSKE, CYPER-M and CPF at all the concentrations. The RCSKE and CPF significantly increased the CES activity, while CYPER-M caused a significant decrease in the activity in adult Z. variegatus. Conclusion: The seed kernel extract of Ricinus communis is an effective pesticidal agent and hence, it could be a source of biopesticide alternative with greater potential than cypermethrin and chlorpyrifos. In addition, the antioxidant, acetylcholinesterase and carboxylesterase enzymes in the nymphs of Z. variegatus grasshoppers are more susceptible to the effect of the extract than in the adult grasshoppers.

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