A rapid in vitro leaf inoculation assay to investigate Phytophthora palmivora –coconut interactions

2021 ◽  
Author(s):  
Gangaraj Karyath Palliyath ◽  
Muralikrishna Kilingar Subrahmanya ◽  
Ginny Antony ◽  
Sahu Binod Bihari ◽  
Vinayaka Hegde ◽  
...  
Keyword(s):  
Phytophthora Palmivora ◽  
Inoculation Assay

scholarly journals Agrobacterium tumefaciens Transformation of the Radiation Hypersensitive Arabidopsis thaliana Mutants uvh1 and rad5

1998 ◽  
Vol 11 (11) ◽  
pp. 1136-1141 ◽  
Author(s):  
Jaesung Nam ◽  
Kirankumar S. Mysore ◽  
Stanton B. Gelvin
Keyword(s):  
Arabidopsis Thaliana ◽  
Agrobacterium Tumefaciens ◽  
Transformation Process ◽  
Stable Transformation ◽  
Wild Type ◽  
Dna Integration ◽  
Agrobacterium Tumefaciens Transformation ◽  
Inoculation Assay

The Arabidopsis thaliana mutants uvh1 and rad5, originally identified as radiation hypersensitive, were reported to be deficient in T-DNA integration based on the relative efficiencies of stable transformation and T-DNA transfer. We reassessed these mutants for susceptibility to transformation by Agrobacterium tumefaciens. The mutant rad5 showed a significant reduction in the efficiency of transient as well as stable transformation, compared with its wild-type progenitor. These data indicate that rad5 is blocked at a step in the transformation process prior to T-DNA integration. We additionally found, using both an in vitro root inoculation and an in vivo flower bolt inoculation assay, that the mutant uvh1 is as susceptible to A. tumefaciens-mediated transformation as is its wild-type progenitor, C10.

scholarly journals The Potency of Endofit Fungi in Cocoa as Biological Agent to Control Cocoa Pod Disease Caused by Phytophthota Palmivora (Butler) Butler

2017 ◽  
Vol 1 (1) ◽  
pp. 6
Author(s):  
I Made Sudarma ◽  
Ni Made Puspawati ◽  
I Ketut Suada
Keyword(s):  
Endophytic Fungi ◽  
Endophytic Fungus ◽  
Fungal Endophyte ◽  
Biological Agent ◽  
Phytophthora Palmivora ◽  
In Vitro Test ◽  
Trichoderma Spp ◽  
Endophyte Fungi

Cocoa pod disease caused by the fungus Phytophthora palmivora has resulted in loss of cacao in Indonesia, especially in Bali. So far the disease control strategy is not fully understood. So there is a need to find an alternative by using endophytic fungi associated with cocoa plant. Endophytic fungi are needed to be explored in all parts of the cocoa plant such as stems, leaves and husks. The prevalence of fungal endophyte was determined by the size of its domination on the surface tissue for protection against pathogen. The exploration of the endophytic fungi benefits is aimed at finding biological agent s that could control of pathogenic P. palmivora.  The results showed that 15 types of endophyte fungi have been found in the healthy leaves, stem and pod husks, with the prevalence of fungal endophyte originated from healthy leaf Mecelia sterilia (hyphae sterile) around 30%, the endophyte fungi originated from the healthy cocoa stem are Mycelia sterilia, Neurospora spp and Trichoderma spp around 25%. While the endophytic fungi originated from healthy skin fruit is Trichoderma spp. around 35%. The in vitro test results of endophytic fungi antagonistic against P. palmivora indicated that the endophyte fungi originated from the leaf namely Aspergillus spp was obtained at 80 ± 2%, A. niger 90 ± 2%, A. flavus 100%, and Trichoderma spp. 90 ± 1.5%, the endophytic fungus originated from rods namely Neurospora spp. was 95 ± 2%, and Trichoderma spp. was 90 ± 2%. While the endophytic originated from rind namely Neurospora spp . was 95 ± 1.5 % and Trichoderma spp. was 80 ± 2%. The results of in vivo test of antagonistic endophytic fungi against P. palmivora showed that all of endophytic fungi (Aspergillus sp., A. niger, A. flavus, Neurospora sp., and Trichoderma sp.) have a significant effect in suppressing the growth of mycelium P. palmivora.Keywords: Endophytic Fungus, Phytophthora Palmivora, Inhibition, Prevalence, Biological Agents

scholarly journals Symbiotic and endophytic fungi as biocontrols against cocoa (Theobroma cacao L.) phytopathogens

2017 ◽  
Vol 43 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Raquel Amanda Villamizar-Gallardo ◽  
Oscar Orlando Ortíz-Rodriguez ◽  
Jhon Wilmer Escobar
Keyword(s):  
Theobroma Cacao ◽  
Trichoderma Viride ◽  
Phytophthora Palmivora ◽  
Mycotoxigenic Fungi ◽  
Black Pod ◽  
Antagonistic Potential ◽  
Native Strains ◽  
Biological Methods ◽  
Theobroma Cacao L

ABSTRACT Cocoa (Theobroma cacao L.) is a tropical tree, seriously affected by fungal diseases. To control several pathogens, biological methods are prescribed since they are friendly to the environment and easy to use. The main objective of this study was to assess the biocontrol effect of two native strains, Trichoderma viride and Botryosphaeria quercum, on phytopathogens such as Phytophthora palmivora and Moniliophtora roreri, causal agents of black pod and frosty pod rot diseases, respectively. In addition, biocontrolers were faced on potential mycotoxigenic fungi such as Aspergills flavus and Fusarium solani, which are very common on cocoa. The Bio-Control Index (BCI) was calculated to determine the in vitro biocontrol effect against the four phytopathogens. Results indicated that the best biocontrol agent of phytopathogens was B. quercum, showing BCI of 82.3%, 80.7%, 63.3% and 59.7% for each tested phytopathogen, respectively. Competition for substrate was the dominant biocontrol strategy. As to the origin of strains, those coming from the Department Norte de Santander and Santander showed the highest average inhibition percentage. This study provides an initial screening to the endophytic and antagonistic potential of fungi, specifically those capable of colonizing cocoa pods and soils. Thus, these strains can be used as an efficient biological control alternative against several known phytopathogens of cocoa in the field.

scholarly journals The Secreted Protein MoHrip1 Is Necessary for the Virulence of Magnaporthe oryzae

2019 ◽  
Vol 20 (7) ◽  
pp. 1643 ◽  
Author(s):  
Hai-Zhen Nie ◽  
Lin Zhang ◽  
Hui-Qian Zhuang ◽  
Wen-Jiong Shi ◽  
Xiu-Fen Yang ◽  
...  
Keyword(s):  
Fungal Infection ◽  
Magnaporthe Oryzae ◽  
Biological Function ◽  
Secreted Protein ◽  
Rice Seedlings ◽  
Fungal Virulence ◽  
Complementation Strain ◽  
Rice Leaves ◽  
Inoculation Assay

Secreted effectors from Magnaporthe oryzae play critical roles in the interaction with rice to facilitate fungal infection and disease development. M. oryzae-secreted protein MoHrip1 can improve plant defense as an elicitor in vitro, however, its biological function in fungal infection is not clear. In this study, we found that the expression of mohrip1 was significantly induced in the stages of fungal penetration and colonization. Although dispensable for the growth and conidiation, MoHrip1 was necessary for the full virulence of M. oryzae. Deletion of mohrip1 remarkably compromised fungal virulence on rice seedlings and even on rice leaves with wounds. Rice sheath inoculation assay further demonstrated the defects of mohrip1-deleted mutants on penetration and proliferation in rice cells. Additionally, compared with WT and complementation strain, the inoculation of mohrip1-deleted mutants induced a higher expression of specific defense related genes and a higher production of specific defensive compounds in rice leaves. These data collectively indicated that MoHrip1 is necessary for fungal penetration and invasive expansion, and further full virulence of rice blast fungus.

SELEÇÃO in vitro DE FUNGOS ANTAGÔNICOS A Phytophthora palmivora DA PUPUNHEIRA

2012 ◽  
Vol 24 (3) ◽  
pp. 157-168
Author(s):  
Aline Brito Vaz ◽  
Edna Dora Martins Newman Luz ◽  
Marival Lopes Oliveira ◽  
Stela Dalva Vieira M. Silva ◽  
Maria das Graças C. Parada Costa Silva
Keyword(s):  
Phytophthora Palmivora

scholarly journals A Phytophthora palmivora Extracellular Cystatin-Like Protease Inhibitor Targets Papain to Contribute to Virulence on Papaya

2018 ◽  
Vol 31 (3) ◽  
pp. 363-373 ◽  
Author(s):  
Rebecca Gumtow ◽  
Dongliang Wu ◽  
Janice Uchida ◽  
Miaoying Tian
Keyword(s):  
Protease Inhibitor ◽  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Gene Editing ◽  
Sequence Data ◽  
Cysteine Protease Inhibitor ◽  
Phytophthora Palmivora ◽  
Cysteine Protease Inhibitors ◽  
Successful Infection

Papaya fruits, stems, and leaves are rich in papain, a cysteine protease that has been shown to mediate plant defense against pathogens and insects. Yet the oomycete Phytophthora palmivora is a destructive pathogen that infects all parts of papaya plants, suggesting that it has evolved cysteine protease inhibitors to inhibit papain to enable successful infection. Out of five putative extracellular cystatin-like cysteine protease inhibitors (PpalEPICs) from P. palmivora transcriptomic sequence data, PpalEPIC8 appeared to be unique to P. palmivora and was highly induced during infection of papaya. Purified recombinant PpalEPIC8 strongly inhibited papain enzyme activity, suggesting that it is a functional cysteine protease inhibitor. Homozygous PpalEPIC8 mutants were generated using CRISPR/Cas9-mediated gene editing via Agrobacterium-mediated transformation (AMT). Increased papain sensitivity of in-vitro growth and reduced pathogenicity during infection of papaya fruits were observed for the mutants compared with the wild-type strain, suggesting that PpalEPIC8, indeed, plays a role in P. palmivora virulence by inhibiting papain. This study provided genetic evidence demonstrating that plant-pathogenic oomycetes secrete cystatins as important weapons to invade plants. It also established an effective gene-editing system for P. palmivora by the combined use of CRISPR/Cas9 and AMT, which is expected to be applicable to other oomycetes.

scholarly journals Regional Evaluation of Fungal Pathogen Incidence in Colombian Cocoa Crops

Agriculture ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 44
Author(s):  
Raquel Villamizar-Gallardo ◽  
Johann Osma ◽  
Oscar Ortíz-Rodriguez
Keyword(s):  
Fungal Pathogens ◽  
Morphological Variability ◽  
Phytopathogenic Fungi ◽  
Phytophthora Palmivora ◽  
In Vitro Assays ◽  
Post Conflict ◽  
Solid Media ◽  
Black Pod

The production of cocoa (Theobroma cacao L.) in Colombia has a significant environmental and socioeconomic importance as a promissory crop in the post-conflict process. The department of Norte de Santander has cocoa crops that are dramatically affected by fungal pathogens causing important losses during harvest and post-harvest. Therefore, the current study focused on the determination of the incidence of diseases caused by phytopathogenic fungi in cocoa crops, and the identification of primary phytopathogenic fungi found in biological material from different farms of the region. The study was conducted in four municipalities of the department, by sampling fruits infected with frosty pod rot (FPR) and black pod rot (BPR) that presented in situ incidence ranging from 0.37 to 21.58% and from 1.75 to 35.59%, respectively. The studied hybrid materials, together with clone TSH 65, were found to be the most susceptible, while the remaining clones were more tolerant, especially CCN 51, IMC 67, and ICS95. Fifteen strains were isolated using in vitro assays and then morphologically characterized both in solid media and by microscopy. Nine of them corresponded to the pathogen Moniliophthora roreri, and other six to Phytophthora palmivora. The isolated agents showed in vitro morphological variability, as well as the ability to adapt to different environments when growing in situ.

scholarly journals The Effectiveness of Trichoderma Viride TNU in Inhibiting Infection of Phytophthora Palmivora on Cocoa

2018 ◽  
Vol 5 (1) ◽  
pp. 39
Author(s):  
Samsudin Samsudin ◽  
Rita Harni ◽  
Efi Taufik
Keyword(s):  
Growth And Development ◽  
Plant Protection ◽  
Trichoderma Viride ◽  
Infected Plant ◽  
Phytophthora Palmivora ◽  
Potato Dextrose Agar Medium ◽  
Plant Parts ◽  
Rot Disease

<p>Phytophthora palmivora<em> is a pathogen</em><em>ic fungus</em><em> that causes pod rot and stem cancer in cacao plant. This pathogen was difficult to control because it survives in the form of mycelium and chlamydospores in infected plant parts or in soil. </em>Trichoderma viride<em> is expected to inhibit the growth and development of this pathogen. The study aimed to determine the effectiveness of </em>T. viride<em> in inhibiting </em>P. palmivora<em> infection on cacao, conducted at Plant Protection Laboratory and Greenhouse of Indonesian Industrial and Beverage Crops Research Institute (IIBCRI), Sukabumi from March to December 2014. The </em>T. viride<em> TNU isolates used was purified and propagated in the laboratory. The </em>T. viride<em> inhibition against  </em>P. palmivora<em> growth and development was tested in vitro on potato dextrose agar medium (PDA) and in vivo on infected cacao pods and seedlings. The parameters observed were percentage of inhibition on PDA and the disease progression on infected pods and seedlings. The results showed that </em>T. viride<em> inhibited the growth of </em>P. palmivora<em> with inhibition percentage up to 68.60%, a strong antagonist for </em>P. palmivora<em> on PDA and reduced </em>P. palmivora<em> infection on seedlings in the greenhouse. Applications of </em>T. viride<em> 3 days before or after inoculation with </em>P. palmivora<em> was able to protect cacao seedlings in polybags, respectively by 60% and 45%. However, </em>T. viride<em> has not been able to hinder the development of pod rot disease on cacao.</em><em></em></p>

scholarly journals Fungi pathogenic to the corm of arracacha (Arracada xanthorrhiza) in Puerto Rico

1969 ◽  
Vol 84 (1-2) ◽  
pp. 53-64
Author(s):  
Evelyn Rosa-Márquez ◽  
Lydia I. Rivera ◽  
Carlos E. Ortiz ◽  
Arcángel Rodríguez
Keyword(s):  
Puerto Rico ◽  
Phytophthora Palmivora ◽  
In Vitro Tests ◽  
Fusarium Spp ◽  
Thiophanate Methyl ◽  
Pathogenicity Tests

Phytophthora palmivora, Rhizoctonia sp. and two isolates of Fusarium spp. were identified and associated with the arracacha (Arracada xanthorrhiza) corm rot in pathogenicity tests conducted in vitro and in vivo. In vitro tests revealed that these fungi were pathogenic to the corm. Fungi caused lesions to the corm under greenhouse conditions. Three major symptoms were observed: necrotized roots; necrotized roots with a dry, brown, hard injury to the internal corm tissue; and wet lesions with brown shades. The highest incidence of affected corms occurred with P. palmivora in combination with Rhizoctonia sp., and the lowest was observed in corms inoculated with Rhizoctonia sp. alone. The most severe symptoms were caused by P. palmivora alone and in combination with Rhizoctonia sp. In vitro tests were conducted to evaluate the efficacy of metalaxyl, etridiazofe thiophanate-methyl, and fosetyl-al against the isolated fungi at doses of 5 to 200 mg ai/kg. Among the fungicides tested, etridiazole thiophanate-methyl was effective against all fungi associated with corm rot. Micelial growth of P. palmivora was completely inhibited with metataxyl at all doses and by etridiazole thiophanate-methyl with doses of 20 or more mg ai/kg.

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