scholarly journals An improved control efficacy against tobacco bacterial wilt by an engineered Pseudomonas mosselii expressing the ripAA gene from phytopathogenic Ralstonia solanacearum

2019 ◽  
Author(s):  
Tao Zhuo ◽  
Shiting Chen ◽  
Xiaojing Fan ◽  
Xun Hu ◽  
Huasong Zou
Keyword(s):  
Plant Pathogen ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Biocontrol Agent ◽  
Biocontrol Agents ◽  
Avirulence Gene ◽  
Primary Immune Response ◽  
Systemic Resistance ◽  
Tobacco Plants ◽  
Engineered Strain

AbstractThe environmental bacterium Pseudomonas mosselii produces antagonistic secondary metabolites with inhibitory effects on multiple plant pathogens, including Ralstonia solanacearum, the causal agent of bacterial wilt. In this study, an engineered P. mosselii strain was generated to express R. solanacearum ripAA, which determines incompatible interactions with tobacco plants. The ripAA gene together with its native promoter was integrated into the P. mosselii chromosome. The resulting strain showed no difference in antimicrobial activity against R. solanacearum. Promoter-LacZ fusion and RT-PCR experiments demonstrated that the ripAA gene was transcribed in culture media. Compared with that of the wild type, the engineered strain reduced the disease index by 9.1% for bacterial wilt on tobacco plants. A transcriptome analysis was performed to identify differentially expressed genes in tobacco plants, and the results revealed that ethylene-and jasmonate-dependent defense signaling pathways were induced. These data demonstrated that the engineered P. mosselii expressing ripAA enables improved biological control against tobacco bacterial wilt by the activation of host defense responses.ImportanceNowadays, the use of biocontrol agents is more and more popular in agriculture, but they cannot replaced of chemical agents mostly, due to the poorer control effect. So the study about how to improve the efficacy of biocontrol agents become necessary and urgent. We increase the efficacy against plant pathogen through introducing an avirulence gene from plant pathogen into the biocontrol agent based on “gene to gene” hypothesis. The new engineered strain can improve the systemic resistance and elicit primary immune response of plants. Our research not only provides a new strategy for genetic modification of biocontrol agent, a number of avirulence gene from pathogen or plant can be tested to be expressed in different biocontrol agents to antagonize plant disease, but also help the study of interaction between phythopathogenic avirulence gene and host.

scholarly journals Complete Genome Sequence of Ralstonia solanacearum FJAT-1458, a Potential Biocontrol Agent for Tomato Wilt

2017 ◽  
Vol 5 (14) ◽  
Author(s):  
Deju Chen ◽  
Bo Liu ◽  
Yujing Zhu ◽  
Jieping Wang ◽  
Zheng Chen ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Complete Genome Sequence ◽  
Biocontrol Agent ◽  
Avirulent Strain ◽  
Potential Candidate ◽  
Content Type ◽  
Potential Biocontrol Agent ◽  
Plant Vaccine

ABSTRACT An avirulent strain of Ralstonia solanacearum FJAT-1458 was isolated from a living tomato. Here, we report the complete R. solanacearum FJAT-1458 genome sequence of 6,059,899 bp and 5,241 genes. This bacterial strain is a potential candidate as a biocontrol agent in the form of a plant vaccine for bacterial wilt.

scholarly journals Three Draft Genome Sequences of the Bacterial Plant Pathogen Ralstonia solanacearum, Isolated in Georgia

2017 ◽  
Vol 5 (23) ◽  
Author(s):  
Adam Kotorashvili ◽  
Galina Meparishvili ◽  
Giorgi Gogoladze ◽  
Nato Kotaria ◽  
Maka Muradashvili ◽  
...  
Keyword(s):  
Causative Agent ◽  
Plant Pathogen ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Draft Genome ◽  
Genome Sequences ◽  
Content Type ◽  
Wide Range ◽  
Bacterial Plant Pathogen ◽  
Pepper Plants

ABSTRACT Ralstonia solanacearum, the causative agent of bacterial wilt, is a devastating bacterial plant pathogen with a wide range of hosts. We report here the first draft genome sequences for three strains of Ralstonia solanacearum isolated from infected potato, tomato, and pepper plants in Georgia.

scholarly journals Improvement of the Fungal Biocontrol Agent Trichoderma atroviride To Enhance both Antagonism and Induction of Plant Systemic Disease Resistance

2005 ◽  
Vol 71 (7) ◽  
pp. 3959-3965 ◽  
Author(s):  
Kurt Brunner ◽  
Susanne Zeilinger ◽  
Rosalia Ciliento ◽  
Sheridian L. Woo ◽  
Matteo Lorito ◽  
...  
Keyword(s):  
Glucose Oxidase ◽  
Biocontrol Agent ◽  
Systemic Disease ◽  
Pythium Ultimum ◽  
Biocontrol Agents ◽  
Systemic Resistance ◽  
Infested Soil ◽  
Trichoderma Atroviride ◽  
Transgenic Strain ◽  
Wild Type

ABSTRACT Biocontrol agents generally do not perform well enough under field conditions to compete with chemical fungicides. We determined whether transgenic strain SJ3-4 of Trichoderma atroviride, which expresses the Aspergillus niger glucose oxidase-encoding gene, goxA, under a homologous chitinase (nag1) promoter had increased capabilities as a fungal biocontrol agent. The transgenic strain differed only slightly from the wild-type in sporulation or the growth rate. goxA expression occurred immediately after contact with the plant pathogen, and the glucose oxidase formed was secreted. SJ3-4 had significantly less N-acetylglucosaminidase and endochitinase activities than its nontransformed parent. Glucose oxidase-containing culture filtrates exhibited threefold-greater inhibition of germination of spores of Botrytis cinerea. The transgenic strain also more quickly overgrew and lysed the plant pathogens Rhizoctonia solani and Pythium ultimum. In planta, SJ3-4 had no detectable improved effect against low inoculum levels of these pathogens. Beans planted in heavily infested soil and treated with conidia of the transgenic Trichoderma strain germinated, but beans treated with wild-type spores did not germinate. SJ3-4 also was more effective in inducing systemic resistance in plants. Beans with SJ3-4 root protection were highly resistant to leaf lesions caused by the foliar pathogen B. cinerea. This work demonstrates that heterologous genes driven by pathogen-inducible promoters can increase the biocontrol and systemic resistance-inducing properties of fungal biocontrol agents, such as Trichoderma spp., and that these microbes can be used as vectors to provide plants with useful molecules (e.g., glucose oxidase) that can increase their resistance to pathogens.

scholarly journals Integrated management of bacterial wilt of ginger incited by Ralstonia solanacearum

2020 ◽  
Vol 15 (2) ◽  
pp. 86-91
Author(s):  
Roop Singh
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Root Length ◽  
Organic Amendment ◽  
Integrated Management ◽  
Shoot Length ◽  
Biocontrol Agents ◽  
Seedling Mortality ◽  
Vigour Index ◽  
Seed Rot

An experiment was conducted to find out the integrated management of Ralstonia solanacearum infecting ginger. Two antibiotics, two biocontrol agents, one phytoextract and one organic amendment and their combination were used. The average reduction in pre emergence seed rot and post emergence seedling mortality recorded with all the treatments tested were ranged from 16.50 to 80.39 per cent over untreated. However, significantly highest reduction in average preemergence seed rot and post- emergence seedling mortality was recorded with streptocycline + P. fluorescens (80.39%). This was followed by streptocycline + karanj cake (72.31%), streptocycline + T. viride (69.55%), streptocycline (58.68%), karanj cake + A. sativum (48.49%), P. fluorescens (44.94%), karanj cake (36.79%). Whereas, T. viride, A. sativum and gentamycin were found least effective with comparatively minimum reduction in average mortality, 26.94, 20.94 and 16.50 per cent, respectively. Of the treatments tested, significantly highest root length (8.60 cm), shoot length (18.43 cm) and vigour index (2342.69) were recorded with streptocycline + P. fluorescens.

scholarly journals Induced Systemic Resistance by Bacillus vallismortis EXTN-1 Suppressed Bacterial Wilt in Tomato Caused by Ralstonia solanacearum

2007 ◽  
Vol 23 (1) ◽  
pp. 22-25 ◽  
Author(s):  
Kyung-Seok Park ◽  
Diby Paul ◽  
Yong-Ki Kim ◽  
Ki-Woong Nam ◽  
Young-Kee Lee ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Induced Systemic Resistance ◽  
Systemic Resistance ◽  
Bacillus Vallismortis

scholarly journals Penapisan dan potensi bakteri endofit asal tanaman Arecaceae sebagai agens pengendali hayati cendawan Pestalotiopsis sp. penyebab penyakit bercak daun pada kelapa kopyor (Cocos nucifera) [Selection and potency of endophytic bacteria from Arecaceae as biocontrol agents of Pestalotiopsis sp. causing leaf spot diseae on kopyor coconut (Cocos nucifera)]

2017 ◽  
Vol 85 (1) ◽  
Author(s):  
Deden ERIS ◽  
Abdul MUNIF ◽  
Bonny PW SOEKARNO ◽  
Agus PURWANTARA
Keyword(s):  
Plant Pathogen ◽  
Oil Palm ◽  
Leaf Spot ◽  
Endophytic Bacteria ◽  
Biocontrol Agent ◽  
Cocos Nucifera ◽  
Recessive Gene ◽  
Biocontrol Agents ◽  
Leaf Spot Disease ◽  
Bactris Gasipaes

 Kopyor is a recessive-gene-trait coconut that has a delicious taste and high prices. One of several major problems of kopyor coconut cultivation is leaf spot disease. Endophytic bacteria originated from Arecaceae can be used as a biocontrol agents to control the disease in a sustainable way. The objective of the research was to select endophytic bacteria isolated from Arecaceae roots and leaves such as Pejibaye (Bactris gasipaes), Oil Palm (Elaeis guinensis), Kopyor Coconut (Cocos nucifera), Sugar Palm (Arenga pinnata) and Nibung (Oncosperma filamentosa) as biocontrol agent of Pestalotiopsis sp. Fourty isolates of endophyte bacteria are not pathogen to plant or animal and human. There are seven best selected endophytic isolates that can inhibit Pestalotiopsis sp. Some of them have the ability to dissolve phosphate, produce IAA, chitinase, and fix nitrogen. Those isolates are  EAKSS 502, EAKSS 507, EAKSS 509, EAKSS 510, EAAPN 237, EAONN 545 and EAKPN 201. EAKPN 201 is the best candidate as biocontrol agent againts Pestalotiopsis sp. with 64,4% inhibition of Pestalotiopsis sp. on antagonist test. [Keywords:  Palmae, plant pathogen, antagonist agents,  antibiotict test]AbstrakKopyor adalah kelapa dengan sifat gen resesif yang memiliki rasa lezat dan harga yang tinggi. Salah satu masalah utama dalam pembudidayaan kelapa kopyor adalah penyakit bercak daun. Bakteri endofitik yang berasal dari tanaman Arecaceae dapat digunakan sebagai agens pengendali hayati dalam mengendalikan penyakit secara berkelanjutan. Penelitian ini bertujuan untuk menseleksi bakteri endofit yang berasal dari akar dan daun tanaman Arecaceae seperti Pejibaye (Bactris gasipaes), Kelapa Sawit (Elaeis guinensis), Kopyor Coconut (Cocos nucifera), Aren (Arenga pinnata) dan Nibung (Oncosperma filamentosa) yang berfungsi sebagai agen biokontrol Pestalotiopsis sp. Empat puluh isolat bakteri endofit non patogen terhadap tumbuhan atau hewan dan manusia berhasil diperoleh. Tujuh isolat bakteri endofit memiliki daya penghambatan terbaik terhadap cendawan Pestalotiopsis sp. Beberapa isolat memiliki kemampuan dalam melarutkan fosfat, memproduksi IAA, kitinase dan mengikat nitrogen. Ketujuh isolat tersebut yaitu isolat EAKSS 502, EAKSS 507, EAKSS 509, EAKSS 510, EAAPN 237, EAONN 545 dan EAKPN 201  EAKPN 201 adalah kandidat terbaik sebagai agen biokontrol untuk Pestalotiopsis sp. dengan penghambatan sebesar 64,4% pada uji antagonis.[Kata kunci:  Palem-paleman, patogen tanaman, antagonis,  uji antibiosis]

scholarly journals Relationship Between Avirulence Gene (avrA) Diversity in Ralstonia solanacearum and Bacterial Wilt Incidence

2004 ◽  
Vol 17 (12) ◽  
pp. 1376-1384 ◽  
Author(s):  
Alison E. Robertson ◽  
W. Patrick Wechter ◽  
Timothy P. Denny ◽  
Bruce A. Fortnum ◽  
Daniel A. Kluepfel
Keyword(s):  
United States ◽  
South Carolina ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Disease Incidence ◽  
Southeastern United States ◽  
Avirulence Gene ◽  
Avirulent Strain ◽  
Wild Type ◽  
North And South

Bacterial wilt, caused by Ralstonia solanacearum, is a serious disease of tobacco in North and South Carolina. In contrast, the disease rarely occurs on tobacco in Georgia and Florida, although bacterial wilt is a common problem on tomato. We investigated whether this difference in disease incidence could be explained by qualitative characteristics of avirulence gene avrA in the R. solanacearum population in the southeastern United States. Sequence analysis established that wild-type avrA has a 792-bp open reading frame. Polymerase chain reaction (PCR) amplification of avrA from 139 R. solanacearum strains generated either 792-bp or ≈960-bp DNA fragments. Strains that elicited a hypersensitive reaction (HR) on tobacco contained the 792-bp allele, and were pathogenic on tomato and avirulent on tobacco. All HR-negative strains generated a ≈960-bp DNA fragment, and wilted both tomato and tobacco. The DNA sequence of avrA in six HR-negative strains revealed the presence of one of two putative miniature inverted-repeat transposable elements (MITEs): a 152-bp MITE between nucleotides 542 and 543, or a 170-bp MITE between nucleotides 461 and 462 or 574 and 575. Southern analysis suggested that the 170-bp MITE is unique to strains from the southeastern United States and the Caribbean. Mutated avrA alleles were present in strains from 96 and 75% of North and South Carolina sites, respectively, and only in 13 and 0% of the sites in Georgia and Florida, respectively. Introduction of the wild-type allele on a plasmid into four HR-negative strains reduced their virulence on both tobacco and tomato. Inactivation of avrA in an HR-positive, avirulent strain, resulted in a mutant that was weakly virulent on tobacco. Thus, the incidence of bacterial wilt of tobacco in the southeastern United States is partially explained by which avrA allele dominates the local R. solanacearum population.

Sign in / Sign up

Export Citation Format

Share Document