scholarly journals White Mold on Pea Caused by Sclerotinia sclerotiorum: A New Threat for Pea Cultivation in Bangladesh

2020 ◽  
Author(s):  
Md. Rabiul Islam ◽  
Ananya Prova ◽  
Md. Tanbir Rubayet ◽  
Md. Mahidul Islam Masum ◽  
Md. Motaher Hossain
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Foliar Application ◽  
Management Strategies ◽  
Carbon Sources ◽  
Hyphal Growth ◽  
White Mold ◽  
In Planta ◽  
Severity Rating ◽  
Internal Transcribed Spacer Sequences ◽  
Sclerotial Development

A new disease causing the tan to light brown blighted stems and pods has occurred in 2.6% pea (Pisum sativum L.) plants with an average disease severity rating of 3.7 in Chapainawabganj district, Bangladesh. A fungus with white appressed mycelia and large sclerotia was consistently isolated from symptomatic tissues. The fungus formed funnel-shaped apothecia with sac-like ascus and endogenously formed ascospores. Healthy pea plants inoculated with the fungus produced typical white mold symptoms. The internal transcribed spacer sequences of the fungus were 100% similar to that recovered from an epitype of Sclerotinia sclerotiorum, considering the fungus to be the causative agent of white mold. Mycelial growth and sclerotial development of S. sclerotiorum were favored at 20°C and pH 5.0. Glucose was the best carbon sources to support hyphal growth and sclerotia formation. Bavistin and Amistar Top inhibited the radial growth of the fungus completely at the lowest concentration. In planta, foliar application of Amistar Top showed the considerable potential to control the disease at 1.0% concentration until 7 days after spraying, while Bavistin prevented infection significantly until 15 days after spraying. A large majority (70.93%) of genotypes including tested released pea cultivars were susceptible, while six genotypes (6.98%) appeared resistant to the disease. These results could be important for management strategies aiming to control the incidence of S. Sclerotinia and eliminate yield loss in pea.

scholarly journals A Sclerotinia sclerotiorum Transcription Factor Involved in Sclerotial Development and Virulence on Pea

mSphere ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Hyunkyu Sang ◽  
Hao-Xun Chang ◽  
Martin I. Chilvers
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Sclerotinia Sclerotiorum ◽  
Culture Medium ◽  
Expression Patterns ◽  
White Mold ◽  
In Planta ◽  
Content Type ◽  
Sclerotial Development

ABSTRACT Sclerotinia sclerotiorum is a plant-pathogenic ascomycete fungus and infects over 400 host plants, including pea (Pisum sativum L.). The fungus causes white mold on pea, and substantial yield loss is attributed to the disease. To improve white mold management, further understanding of S. sclerotiorum pathogenicity is crucial. In this study, 389 transcription factors (TFs) were mined from the complete genome sequence of S. sclerotiorum and their in planta expression patterns were determined in susceptible and partially resistant pea lines and compared to in vitro expression patterns on culture medium. One of the transcription factors was significantly induced in planta at 24 and 48 h postinfection compared to the expression in vitro. This putative C6 transcription factor of S. sclerotiorum (SsC6TF1) was knocked down using a gene-silencing approach to investigate its functions in vegetative growth and sclerotial development as well as its virulence and pathogenicity in pea. While the SsC6TF1 knockdown mutants had hyphal growth rates identical to those of the wild-type strain and were capable of infection, the knockdown mutants produced no sclerotia or significantly fewer and smaller sclerotia on the culture medium and exhibited reduced virulence on both pea lines. This study profiled genome-wide expression for S. sclerotiorum transcription factors in planta and in vitro and functionally characterized a novel transcription factor, SsC6TF1, which positively regulates sclerotial development and virulence on pea. The finding provides molecular insights into S. sclerotiorum biology and interaction with pea and other economically important crops. IMPORTANCE White mold, caused by Sclerotinia sclerotiorum, is a destructive disease on important legume species such as soybean, dry bean, and pea. This study investigated expression levels of transcription factors in S. sclerotiorum in planta (pea lines) and in vitro (culture medium). One transcription factor displaying high expression in planta was found to be involved in sclerotial development and virulence on pea. This report provides a new understanding regarding transcription factors of S. sclerotiorum in development and virulence.

Interactions between Sclerotinia sclerotiorum and Epicoccum purpurascens

1991 ◽  
Vol 69 (11) ◽  
pp. 2503-2510 ◽  
Author(s):  
Ting Zhou ◽  
R. D. Reeleder ◽  
S. A. Sparace
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Mycelial Growth ◽  
Germ Tube ◽  
Hyphal Growth ◽  
White Mold ◽  
Antifungal Compounds ◽  
Sterile Culture ◽  
Pod Yield ◽  
Culture Filtrates ◽  
Ascospore Germination

Sterile culture filtrates of Epicoccum purpurascens decreased severity of white mold of bean and increased pod yield when applied prior to inoculation of beans with Sclerotinia sclerotiorum. Extracts of these culture filtrates inhibited ascospore germination and mycelial growth of S. sclerotiorum. Similar inhibition of hyphal growth of S. sclerotiorum occurred when dual cultured with E. purpurascens. Contact and penetration of hyphae of S. sclerotiorum by hyphae of E. purpurascens occurred rarely on agar-covered slides and was not observed on flower petals. Inhibition of ascospore germination and germ-tube elongation occurred on agar-covered slides where E. purpurascens had been grown previously; however, addition of nutrients decreased inhibition. Colonization of bean flowers by E. purpurascens reduced white mold incidence. The degree of disease control was affected by addition of nutrients and whether or not colonized flowers were autoclaved. Key words: antifungal compounds, competition, biological control, white mold, Phaseolus.

scholarly journals Spontaneous and Fungicide-Induced Genomic Variation in Sclerotinia sclerotiorum

2020 ◽  
pp. PHYTO-10-20-047
Author(s):  
Nikita Gambhir ◽  
Zhian N. Kamvar ◽  
Rebecca Higgins ◽  
B. Sajeewa Amaradasa ◽  
Sydney E. Everhart
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Plant Pathogens ◽  
Management Strategies ◽  
Genomic Variation ◽  
Sublethal Dose ◽  
P Value ◽  
Nucleotide Polymorphisms ◽  
In Planta ◽  
Induced Mutations ◽  
Fungal Plant Pathogens

Stress from exposure to sublethal fungicide doses may cause genomic instability in fungal plant pathogens, which may accelerate the emergence of fungicide resistance or other adaptive traits. In a previous study, five strains of Sclerotinia sclerotiorum were exposed to sublethal doses of four fungicides with different modes of action, and genotyping showed that such exposure induced mutations. The goal of the present study was to characterize genome-wide mutations in response to sublethal fungicide stress in S. sclerotiorum and study the effect of genomic background on the mutational repertoire. The objectives were to determine the effect of sublethal dose exposure and genomic background on mutation frequency/type, distribution of mutations, and fitness costs. Fifty-five S. sclerotiorum genomes were sequenced and aligned to the reference genome. Variants were called and quality filtered to obtain high confidence calls for single nucleotide polymorphisms (SNPs), insertions/deletions (INDELs), copy number variants, and transposable element (TE) insertions. Results suggest that sublethal fungicide exposure significantly increased the frequency of INDELs in two strains from one genomic background (P value ≤ 0.05), while TE insertions were generally repressed for all genomic backgrounds and under all fungicide exposures. The frequency and/or distribution of SNPs, INDELs, and TE insertions varied with genomic background. A propensity for large duplications on chromosome 7 and aneuploidy of this chromosome were observed in the S. sclerotiorum genome. Mutation accumulation did not significantly affect the overall in planta strain aggressiveness (P value > 0.05). Understanding factors that affect pathogen mutation rates can inform disease management strategies that delay resistance evolution.

Saccharin Provides Protection and Activates Defense Mechanisms in Wheat Against the Hemibiotrophic Pathogen Zymoseptoria tritici

Plant Disease ◽  
2020 ◽  
Author(s):  
Samara Mejr ◽  
Maryline Magnin-Robert ◽  
Beatrice Randoux ◽  
Alina Ghinet ◽  
Patrice Halama ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Foliar Application ◽  
Crop Protection ◽  
Hyphal Growth ◽  
In Planta ◽  
Zymoseptoria Tritici ◽  
Gene Encoding ◽  
Challenge Inoculation ◽  
Pathogenesis Related Protein

Plant resistance inducers are among the most promising alternatives to develop sustainable crop protection. Here, we examined the ability of saccharin, a metabolite derived from probenazole, to protect wheat against Zymoseptoria tritici, the most frequently occurring and damaging foliar pathogen on this crop. The experiments were performed in the greenhouse by treating seedlings of the wheat cv. Alixan with 15 mM saccharin two days before challenge inoculation with the Z. tritici pathogenic strain T02596. Foliar application of saccharin resulted in 77 % disease severity reduction when compared to non-treated control plants. In vitro and in planta assays showed that saccharin did not exhibit any direct antifungal effect, neither on spore germination, nor on hyphal growth. Molecular investigations from 2 to 7 days post-treatment (dpt) revealed that saccharin treatment up-regulates the expression of genes encoding for lipoxygenase (LOX) at all sampled time-points and pathogenesis-related protein 1 (PR1) at 7 dpt, in both non-infectious and infectious contexts, as well as peroxidase (POX2) in non-infectious conditions. However, saccharin did not induce significant change in the expression of PAL gene encoding for phenylalanine ammonia-lyase. Our findings report for the first time the potential of saccharin to confer protection in wheat against Z. tritici through an elicitation and priming of LOX and PR gene-related defense pathways. Further investigations would provide a better deciphering of defense mechanisms activated by this molecule in wheat against Z. tritici.

A Trojan horse approach for white mold biocontrol: Paraconiothyrium endophytes promotes grass growth and inhibits Sclerotinia sclerotiorum

2021 ◽  
pp. 104685
Author(s):  
Natálie Martins Alves ◽  
Rafaela Araújo Guimarães ◽  
Sarah Silva Costa Guimarães ◽  
Amanda Frausino Faria ◽  
Ítalo Augusto Férrer Melo Santos ◽  
...  
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Trojan Horse ◽  
White Mold ◽  
Grass Growth

scholarly journals In Silico Analyses of Rice Thionin Genes and the Antimicrobial Activity of OsTHION15 Against Phytopathogens

2019 ◽  
Vol 109 (1) ◽  
pp. 27-35
Author(s):  
Krissana Boonpa ◽  
Suparuk Tantong ◽  
Kamonwan Weerawanich ◽  
Pawinee Panpetch ◽  
Onanong Pringsulaka ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Stress Responses ◽  
In Silico ◽  
Pathogenic Bacteria ◽  
Hyphal Growth ◽  
In Planta ◽  
Recombinant Peptide ◽  
Plant Disease Control ◽  
Helminthosporium Oryzae ◽  
In Silico Analyses

Thionins are a family of antimicrobial peptides. We performed in silico expression analyses of the 44 rice (Oryza sativa) thionins (OsTHIONs). Modulated expression levels of OsTHIONs under different treatments suggest their involvement in many processes, including biotic, abiotic, and nutritional stress responses, and in hormone signaling. OsTHION15 (LOC_Os06g32600) was selected for further characterization based on several in silico analyses. OsTHION15 in O. sativa subsp. indica ‘KDML 105’ was expressed in all of the tissues and organs examined, including germinating seed, leaves, and roots of seedlings and mature plants, and inflorescences. To investigate the antimicrobial activity of OsTHION15, we produced a recombinant peptide in Escherichia coli Rosetta-gami (DE3). The recombinant OsTHION15 exhibited inhibitory activities toward rice-pathogenic bacteria such as Xanthomonas oryzae pv. oryzae and Pectobacterium carotovorum pv. atroseptica, with minimum inhibitory concentrations of 112.6 and 14.1 µg ml−1, respectively. A significant hyphal growth inhibition was also observed toward Fusarium oxysporum f. sp. cubense and Helminthosporium oryzae. In addition, we demonstrated the in planta antibacterial activity of this peptide in Nicotiana benthamiana against X. campestris pv. glycines. These activities suggest the possible application of OsTHION15 in plant disease control.

Efficacy of three greenhouse screening methods for the identification of physiological resistance to white mold in dry bean

2009 ◽  
Vol 89 (4) ◽  
pp. 755-762 ◽  
Author(s):  
H Terán ◽  
S P Singh
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Sclerotinia Sclerotiorum ◽  
Screening Method ◽  
White Mold ◽  
Screening Methods ◽  
Post Inoculation ◽  
Dry Bean ◽  
Physiological Resistance ◽  
Nueva Granada

White mold (WM) caused by Sclerotinia sclerotiorum (Lib.) de Bary is the most devastating disease of common bean (dry and snap or garden bean) (Phaseolus vulgaris L.) in North America. The use of a reliable screening method (SM) in common bean is crucial to improve physiological resistance to WM. The objective of this study was to compare the efficacy of three SM to identify physiological resistance in dry bean genotypes with different evolutionary origins and levels of resistance. Screening methods tested were: (i) the modified straw test or cut–stem (CSM); (ii) infected bean flower (IFL); and (iii) infected oat seed (IOS). A 195, ICA Bunsi, Othello, and VCW 54 dry bean were tested with the three SM. The experimental design was a split plot in randomized complete blocks with three replications in 2007 and 2008. Two independent inoculations 1 wk apart for each SM were made. The WM reaction was scored at 16, 23, and 33 d post-inoculation (DPI) using a 1 to 9 scale. There were highly significant differences between SM and its interaction with years. The CSM and IFL were the most consistent and highly correlated (r > 0.70, P < 0.01). Interspecific breeding line VCW 54 consistently had the highest WM resistance across years, SM, and evaluation dates, followed by A 195. White mold scores increased with delayed evaluations. Thus, CSM or IFL with disease assessed 33 DPI should be used for identifying common bean genotypes with high levels of physiological resistance to WM.Key words: Common bean, growth habit, race Mesoamerica, race Nueva Granada, Phaseolus vulgaris, Sclerotinia sclerotiorum

First characterization of a newly emerging phytopathogen, Sclerotinia sclerotiorum causing white mold in pea

2021 ◽  
Author(s):  
Md. Rabiul Islam ◽  
Abdul Mannan Akanda ◽  
Md. Mofazzal Hossain ◽  
Md. Motaher Hossain
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
White Mold
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