scholarly journals 4-Ethylphenol, A Volatile Organic Compound Produced by Disease-Resistant Soybean, Is a Potential Botanical Agrochemical Against Oomycetes

2021 ◽  
Vol 12 ◽  
Author(s):  
Ting Ge ◽  
Wenteng Gao ◽  
Changhui Liang ◽  
Chao Han ◽  
Yong Wang ◽  
...  
Keyword(s):  
Root Rot ◽  
Biological Control Agent ◽  
Crop Protection ◽  
Phytophthora Sojae ◽  
Phytophthora Nicotianae ◽  
Biologically Active ◽  
Gaeumannomyces Graminis ◽  
Economic Losses ◽  
Soybean Root ◽  
Volatile Organic

Oomycetes, represented by Phytophthora, are seriously harmful to agricultural production, resulting in a decline in grain quality and agricultural products and causing great economic losses. Integrated management of oomycete diseases is becoming more challenging, and plant derivatives represent effective alternatives to synthetic chemicals as novel crop protection solutions. Biologically active secondary metabolites are rapidly synthesized and released by plants in response to biotic stress caused by herbivores or insects, as well as pathogens. In this study, we identified groups of volatile organic compounds (VOCs) from soybean plants inoculated with Phytophthora sojae, the causal agent of soybean root rot. 4-Ethylphenol was present among the identified VOCs and was induced in the incompatible interaction between the plants and the pathogen. 4-Ethylphenol inhibited the growth of P. sojae and Phytophthora nicotianae and had toxicity to sporangia formation and zoospore germination by destroying the pathogen cell membrane; it had a good control effect on soybean root rot and tobacco black shank in the safe concentration range. Furthermore, 4-Ethylphenol had a potent antifungal activity against three soil-borne phytopathogenic fungi, Rhizoctonia solani, Fusarium graminearum, and Gaeumannomyces graminis var tritici, and four forma specialis of Fusarium oxysporum, which suggest a potential to be an eco-friendly biological control agent.

scholarly journals Lauric Acid Is a Potent Biological Control Agent That Damages the Cell Membrane of Phytophthora sojae

2021 ◽  
Vol 12 ◽  
Author(s):  
Changhui Liang ◽  
Wenteng Gao ◽  
Ting Ge ◽  
Xinwei Tan ◽  
Jiayu Wang ◽  
...  
Keyword(s):  
Biological Control ◽  
Cell Membrane ◽  
Lauric Acid ◽  
Plant Pathogens ◽  
Biological Control Agent ◽  
Biological Activities ◽  
Crop Protection ◽  
Phytophthora Sojae ◽  
Biologically Active ◽  
Leaf Volatiles

Sustainable management of plant pathogens is becoming more challenging, and novel solutions are needed. Plant biologically active secondary metabolites are important sources of novel crop protection chemistry. Effective individual compounds of these natural products have the potential to be successful new agrochemicals. In this study, we identified lauric acid (LA) from soybean defense leaf volatiles. LA inhibited the growth of Phytophthora sojae, the causal agent of soybean root rot. It influenced mycelial development, sporangium formation, and zoospore generation and germination by damaging the P. sojae cell membrane. Additionally, we showed that LA and several of its derivatives, such as glycerol monolaurate (GML), had similar biological activities. Both LA and GML were safe to soybean plants when used at less than 0.3 g a.i./plant and could promote soybean growth, implying their potential as eco-friendly biological control agents.

Corrigendum to: Systematic review of defense responses against Phytophthora and strategies to manage Phytophthora diseases in citrus

2021 ◽  
Vol 48 (10) ◽  
pp. 1086
Author(s):  
Adielle R. da Silva ◽  
Kaliane N. S. Pinto ◽  
Bianca E. Maserti ◽  
Hermes P. Santos-Filho ◽  
Abelmon da S. Gesteira
Keyword(s):  
Systematic Review ◽  
Root Rot ◽  
Crop Protection ◽  
Plant Defence ◽  
Academic Research ◽  
Defense Responses ◽  
Fruit Rot ◽  
Economic Losses ◽  
Foot Rot ◽  
Fibrous Root

Phytophthora spp. are the causal agents of gummosis or foot rot, fibrous root rot, and fruit brown rot diseases that affect the roots, trunk, and fruits of citrus trees, causing severe economic losses. This work presents an updated systematic review addressing the defence responses in citrus against Phytophthora and the strategies to manage Phytophthora diseases. Applying a new method of search based on an explicit, rigorous, and transparent methodology. For this purpose, a systematic literature review was conducted using the databases available for academic research. The main plant defence mechanisms reported in the cited papers are the hypersensitivity response, cell wall reinforcement, production of pathogenesis-related proteins, and expression of defence-related genes. Moreover, the main strategies to manage Phytophthora root rot are organic compounds in the soil and biological control with fungi and bacteria. In addition, inhibition of Phytophthora gummosis or canker by applying new oomycota fungicides and reducing the incidence of brown fruit rot through the application of potassium phosphite have also been reported. Moreover, modern plant biotechnology techniques can help to accelerate the selection of resistant rootstocks in breeding programs, as controlled crossings for the generation of hybrids, somatic hybridisation, transgenic citrus plants, mapped genomic regions of Quantitative Trait Loci (QTLs), candidate genes, metabolic markers and comparative transcriptomic. These innovative techniques represent a suitable tool to breed new Phytophthora resistant rootstocks, which is widely recognised as the best strategy to face gummosis or foot rot, fibrous root rot and ultimately minimise the expensive use of pesticides in crop protection.

scholarly journals RNAseq Reveals Differential Gene Expression Contributing to Phytophthora nicotianae Adaptation to Partial Resistance in Tobacco

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 656
Author(s):  
Jing Jin ◽  
Rui Shi ◽  
Ramsey Steven Lewis ◽  
Howard David Shew
Keyword(s):  
Partial Resistance ◽  
Molecular Mechanisms ◽  
Biological Activities ◽  
Effective Means ◽  
Phytophthora Nicotianae ◽  
Economic Losses ◽  
Black Shank ◽  
Differential Gene ◽  
Go Terms

Phytophthora nicotianae is a devastating oomycete plant pathogen with a wide host range. On tobacco, it causes black shank, a disease that can result in severe economic losses. Deployment of host resistance is one of the most effective means of controlling tobacco black shank, but adaptation to complete and partial resistance by P. nicotianae can limit the long-term effectiveness of the resistance. The molecular basis of adaptation to partial resistance is largely unknown. RNAseq was performed on two isolates of P. nicotianae (adapted to either the susceptible tobacco genotype Hicks or the partially resistant genotype K 326 Wz/Wz) to identify differentially expressed genes (DEGs) during their pathogenic interactions with K 326 Wz/Wz and Hicks. Approximately 69% of the up-regulated DEGs were associated with pathogenicity in the K 326 Wz/Wz-adapted isolate when sampled following infection of its adapted host K 326 Wz/Wz. Thirty-one percent of the up-regulated DEGs were associated with pathogenicity in the Hicks-adapted isolate on K 326 Wz/Wz. A broad spectrum of over-represented gene ontology (GO) terms were assigned to down-regulated genes in the Hicks-adapted isolate. In the host, a series of GO terms involved in nuclear biosynthesis processes were assigned to the down-regulated genes in K 326 Wz/Wz inoculated with K 326 Wz/Wz-adapted isolate. This study enhances our understanding of the molecular mechanisms of P. nicotianae adaptation to partial resistance in tobacco by elucidating how the pathogen recruits pathogenicity-associated genes that impact host biological activities.

scholarly journals Integrated Control of Rhizoctonia Crown and Root Rot of Sugar Beet with Fungicides and Antagonistic Bacteria

Plant Disease ◽  
2001 ◽  
Vol 85 (7) ◽  
pp. 718-722 ◽  
Author(s):  
Sebastian Kiewnick ◽  
Barry J. Jacobsen ◽  
Andrea Braun-Kiewnick ◽  
Joyce L. A. Eckhoff ◽  
Jerry W. Bergman
Keyword(s):  
Sugar Beet ◽  
Root Rot ◽  
Integrated Control ◽  
The United States ◽  
Field Trials ◽  
Sugar Yield ◽  
Economic Losses ◽  
Yield Increase ◽  
Leaf Stage ◽  
Crown And Root Rot

Rhizoctonia crown and root rot, caused by the fungus Rhizoctonia solani AG 2-2, is one of the most damaging sugar beet diseases worldwide and causes significant economic losses in more than 25% of the sugar beet production area in the United States. We report on field trials in the years 1996 to 1999 testing both experimental fungicides and antagonistic Bacillus sp. for their potential to reduce disease severity and increase sugar yield in trials inoculated with R. solani AG 2-2. Fungicides were applied as in-furrow sprays at planting or as band sprays directed at the crown at the four-leaf stage, or four- plus eight-leaf stage, while bacteria were applied at the four-leaf stage only. The fungicides azoxystrobin and tebuconazole reduced crown and root rot disease by 50 to 90% over 3 years when used at rates of 76 to 304 g a.i./ha and 250 g a.i./ha, respectively. The disease index at harvest was reduced and the root and sugar yield increased with azoxystrobin compared with tebuconazole. The combination of azoxystrobin applied at 76 g a.i./ha and the Bacillus isolate MSU-127 resulted in best disease reduction and greatest root and sucrose yield increase.

scholarly journals Antagonistic Strain Bacillus amyloliquefaciens XZ34-1 for Controlling Bipolaris sorokiniana and Promoting Growth in Wheat

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1526
Author(s):  
Yanjie Yi ◽  
Youtian Shan ◽  
Shifei Liu ◽  
Yanhui Yang ◽  
Yang Liu ◽  
...  
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Bacillus Amyloliquefaciens ◽  
Biological Control Agent ◽  
Wheat Yield ◽  
Bipolaris Sorokiniana ◽  
Common Root ◽  
Bioactive Substances ◽  
Wheat Seedlings ◽  
Common Root Rot

Common root rot, caused by Bipolaris sorokiniana, is one of the most prevalent diseases of wheat and has led to major declines in wheat yield and quality worldwide. Here, strain XZ34-1 was isolated from soil and identified as Bacillus amyloliquefaciens based on the morphological, physiological, biochemical characteristics and 16S rDNA sequence. Culture filtrate (CF) of strain XZ34-1 showed a high inhibition rate against B.sorokiniana and had a broad antifungal spectrum. It also remarkably inhibited the mycelial growth and spore germination of B. sorokiniana. In pot control experiments, the incidence and disease index of common root rot in wheat seedlings were decreased after treatment with CF, and the biological control efficacy was significant, up to 78.24%. Further studies showed XZ34-1 could produce antifungal bioactive substances and had the potential of promoting plant growth. Lipopeptide genes detection with PCR indicated that strain XZ34-1 may produce lipopeptides. Furthermore, activities of defense-related enzymes were enhanced in wheat seedlings after inoculation with B.sorokiniana and treatment with CF, which showed induced resistance could be produced in wheat to resist pathogens. These results reveal that strain XZ34-1 is a promising candidate for application as a biological control agent against B.sorokiniana.

scholarly journals Assessment of Monoterpene Components in Wild Rose Petals Extract

2020 ◽  
Vol 21 (2) ◽  
pp. 254-262
Author(s):  
Koval Inna
Keyword(s):  
Gas Chromatography ◽  
Steam Distillation ◽  
Botanical Garden ◽  
Component Composition ◽  
Biologically Active ◽  
National Academy Of Sciences ◽  
Volatile Organic ◽  
Rose Petals ◽  
Academy Of Sciences ◽  
Active Substances

The content, component composition, and main directions of the use of monoterpenes of wild rose petals compounds are considered in the research. The study on six wild rose species was carried out in the collection of M.M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine. Volatile organic compounds were isolated by steam distillation, and their determination was performed by means of gas chromatography. R. rugosa petals contained the highest number of monoterpenoids, while R. canina petals – the lowest. In our research twentyone different (acyclic, monocyclic, bicyclic) monoterpenoids were identified, including alcohols, aldehydes, ethers, and ketones. All groups of monoterpenoids are biologically active substances and have a significant effect on the aroma of the studied plants.

Characterization and aggressiveness of take-all root rot pathogens isolated from symptomatic bermudagrass putting greens

2021 ◽  
Author(s):  
Cameron Stephens ◽  
Travis W Gannon ◽  
Marc Cubeta ◽  
Tim L. Sit ◽  
Jim Kerns
Keyword(s):  
Plant Tissue ◽  
Root Rot ◽  
Pathogen Detection ◽  
Infected Plant ◽  
Gaeumannomyces Graminis ◽  
In Planta ◽  
High Resolution Melt ◽  
Putting Greens ◽  
Ultradwarf Bermudagrass ◽  
Take All

Take-all root rot is a disease of ultradwarf bermudagrass putting greens caused by Gaeumannomyces graminis (Gg), Gaeumannomyces sp. (Gx), Gaeumannomyces graminicola (Ggram), Candidacolonium cynodontis (Cc), and Magnaporthiopsis cynodontis (Mc). Many etiological and epidemiological components of this disease remain unknown. Improving pathogen identification and our understanding of the aggressiveness of these pathogens along with growth at different temperatures will advance our knowledge of disease development to optimize management strategies. Take-all root rot pathogens were isolated from symptomatic bermudagrass root and stolon pieces from 16 different golf courses. Isolates of Gg, Gx, Ggram, Cc, and Mc were used to inoculate ‘Champion’ bermudagrass in an in planta aggressiveness assay. Each pathogen was also evaluated at 10, 15, 20, 25, 30, and 35C to determine growth temperature optima. Infected plant tissue was used to develop a real-time PCR high resolution melt assay for pathogen detection. This assay was able to differentiate each pathogen directly from infected plant tissue using a single primer pair. In general, Ggram, Gg, and Gx were the most aggressive while Cc and Mc exhibited moderate aggressiveness. Pathogens were more aggressive when incubated at 30C compared to 20C. While they grew optimally between 24.4 and 27.8C, pathogens exhibited limited growth at 35C and no growth at 10C. These data provide important information on this disease and its causal agents that may improve take-all root rot management.

Phytophthora nicotianae. [Descriptions of Fungi and Bacteria].

1994 ◽  
Author(s):  
G. Hall
Keyword(s):  
Surface Water ◽  
Nicotiana Tabacum ◽  
Geographical Distribution ◽  
Root Rot ◽  
World Wide ◽  
Phytophthora Nicotianae ◽  
Fruit Rot ◽  
Tomato Root ◽  
Ornamental Crops ◽  
The Tropics

Abstract A description is provided for Phytophthora nicotianae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Principally Lycopersicon esculentum, Nicotiana tabacum, Capsicum annuum and Citrus sp. A very large number of other agricultural and ornamental crops, both temperate and tropical, are also affected, including avocado, strawberry, pineapple, papaya, guava, eggplant and durian. DISEASE: Blackshank of tobacco, buckeye of tomato, root and fruit rot of capsicum, root rot of citrus. GEOGRAPHICAL DISTRIBUTION: World-wide, but particularly common in the tropics and sub-tropics. TRANSMISSION: By zoospores in surface water and rainsplash. Chlamydospores (and oospores, when formed) act as perennating structures.

scholarly journals Crop Protection against Botrytis cinerea by Rhizhosphere Biological Control Agent Bacillus velezensis XT1

2020 ◽  
Vol 8 (7) ◽  
pp. 992 ◽  
Author(s):  
Laura Toral ◽  
Miguel Rodríguez ◽  
Victoria Béjar ◽  
Inmaculada Sampedro
Keyword(s):  
Defense Mechanisms ◽  
Biological Control Agent ◽  
Disease Incidence ◽  
Crop Protection ◽  
Preventive Treatment ◽  
Control Agent ◽  
Total Biomass ◽  
Hormone Regulation ◽  
Bacillus Velezensis ◽  
Callose Deposition

This study aims to evaluate the use of Bacillus velezensis strain XT1 as a plant growth-promoting rhizobacterium (PGPR) and biocontrol agent against B. cinerea in tomato and strawberry plants. Foliar and radicular applications of strain XT1 increased plant total biomass as compared to the control and B. cinerea-infected plants, with root applications being, on the whole, the most effective mode of treatment. Applications of the bacterium were found to reduce infection parameters such as disease incidence and severity by 50% and 60%, respectively. We analyzed stress parameters and phytohormone content in order to evaluate the capacity of XT1 to activate the defense system through phytohormonal regulation. Overall, the application of XT1 reduced oxidative damage, while the H2O2 and malondialdehyde (MDA) content was lower in XT1-treated and B. cinerea-infected plants as compared to non-XT1-treated plants. Moreover, treatment with XT1 induced callose deposition, thus boosting the response to pathogenic infection. The results of this study suggest that the signaling and activation pathways involved in defense mechanisms are mediated by jasmonic acid (JA) and ethylene hormones, which are induced by preventive treatment with XT1. The study also highlights the potential of preventive applications of strain XT1 to activate defense mechanisms in strawberry and tomato plants through hormone regulation.

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