Induction of Antimicrobial 3-Deoxyflavonoids in Pome Fruit Trees Controls Fire Blight

2003 ◽  
Vol 58 (11-12) ◽  
pp. 765-770 ◽  
Author(s):  
Heidrun Halbwirth ◽  
Thilo C. Fischer ◽  
Susanne Roemmelt ◽  
Francesco Spinelli ◽  
Karin Schlangen ◽  
...  
Keyword(s):  
Fire Blight ◽  
Fruit Trees ◽  
Effective Control ◽  
Economic Losses ◽  
Bacterial Disease ◽  
Flavonoid Pathway ◽  
Pome Fruit ◽  
New Approach ◽  
Pome Fruits ◽  
Potential Risks

Abstract Fire blight, a devastating bacterial disease in pome fruits, causes severe economic losses worldwide. Hitherto, an effective control could only be achieved by using antibiotics, but this implies potential risks for human health, livestock and environment. A new approach allows transient inhibition of a step in the flavonoid pathway, thereby inducing the formation of a novel antimicrobial 3-deoxyflavonoid controlling fire blight in apple and pear leaves. This compound is closely related to natural phytoalexins in sorghum. The approach does not only provide a safe method to control fire blight: Resistance against different pathogens is also induced in other crop plants.

scholarly journals CRISPR genotyping as complementary tool for epidemiological surveillance of Erwinia amylovora outbreaks

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250280
Author(s):  
Rafael J. Mendes ◽  
João Pedro Luz ◽  
Conceição Santos ◽  
Fernando Tavares
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Blot Hybridization ◽  
Fruit Trees ◽  
Epidemiological Surveillance ◽  
Economic Losses ◽  
Pome Fruit ◽  
Dot Blot ◽  
Virulence Markers ◽  
Clonal Population Structure

Fire blight is a destructive plant disease caused by Erwinia amylovora affecting pome fruit trees, and responsible for large yield declines, long phytosanitary confinements, and high economic losses. In Portugal, the first major fire blight outbreaks occurred in 2010 and 2011, and although later considered eradicated, the emergence of other outbreaks in recent years stressed the need to characterize the E. amylovora populations associated with these outbreaks. In this regard, CRISPR genotyping, assessment of three virulence markers, and semi-quantitative virulence bioassays, were carried out to determine the genotype, and assess the virulence of thirty-six E. amylovora isolates associated with outbreaks occurring between 2010 and 2017 and affecting apple and pear orchards located in the country central-west, known as the main producing region of pome fruits in Portugal. The data gathered reveal that 35 E. amylovora isolates belong to one of the widely-distributed CRISPR genotypes (5-24-38 / D-a-α) regardless the host species, year and region. Ea 680 was the single isolate revealing a new CRISPR genotype due to a novel CR2 spacer located closer to the leader sequence and therefore thought to be recently acquired. Regarding pathogenicity, although dot-blot hybridization assays showed the presence of key virulence factors, namely hrpL (T3SS), hrpN (T3E) and amsG from the amylovoran biosynthesis operon in all E. amylovora isolates studied, pathogenicity bioassays on immature pear slices allowed to distinguish four virulence levels, with most of the isolates revealing an intermediate to severe virulence phenotype. Regardless the clonal population structure of the E. amylovora associated to the outbreaks occurring in Portugal between 2010 and 2017, the different virulence phenotypes, suggests that E. amylovora may have been introduced at different instances into the country. This is the first study regarding E. amylovora in Portugal, and it discloses a novel CRISPR genotype for this bacterium.

From the roots to the stem: unveiling pear root colonization and infection pathways by Erwinia amylovora

2020 ◽  
Vol 96 (12) ◽  
Author(s):  
Ricardo D Santander ◽  
José F Català-Senent ◽  
Àngela Figàs-Segura ◽  
Elena G Biosca
Keyword(s):  
Fire Blight ◽  
Plant Pathogens ◽  
Erwinia Amylovora ◽  
Fluorescent Protein ◽  
Epifluorescence Microscopy ◽  
Economic Losses ◽  
Root Infection ◽  
Pome Fruit ◽  
Infection Pathways ◽  
Biofilm Development

ABSTRACT Fire blight caused by Erwinia amylovora affects pome fruit worldwide, generating serious economic losses. Despite the abundant literature on E. amylovora infection mechanisms of aerial plant organs, root infection routes remain virtually unexplored. Assessing these infection pathways is necessary for a full understanding of the pathogen's ecology. Using the pathosystem Pyrus communis–E. amylovora and different experimental approaches including a green fluorescent protein transformant (GFP1) and epifluorescence microscopy (EFM) and laser confocal scanning microscopy (LCSM), we demonstrated the pathogen's ability to infect, colonize and invade pear roots and cause characteristic fire blight symptoms both in the aerial part and in the root system. Plant infections after soil irrigation with E. amylovora-contaminated water were favored by root damage, which agreed with EFM and LCSM observations. E. amylovora GFP1 cells formed aggregates/biofilms on root surfaces and invaded the cortex through wounds and sites of lateral root emergence. Sugars, sugar-alcohols and amino acids typically secreted by roots, favored the in vitro biofilm development by E. amylovora. Migration of E. amylovora cells to aerial tissues mainly occurred after xylem penetration. Overall, our findings revealed, for the first time, common root infection patterns between E. amylovora and well-known soil borne plant pathogens and endophytes.

scholarly journals Transient Induction of Antimicrobial 3-Deoxyflavonoids does not Affect Pharmacological Compounds in Hawthorn

2008 ◽  
Vol 3 (8) ◽  
pp. 1934578X0800300
Author(s):  
Karin Schlangen ◽  
Heidi Halbwirth ◽  
Silke Peterek ◽  
Christian Gosch ◽  
Alexandra Ringl ◽  
...  
Keyword(s):  
Medicinal Plant ◽  
Fire Blight ◽  
Economic Losses ◽  
Blight Resistance ◽  
Bacterial Disease ◽  
Drug Preparation ◽  
Crataegus Monogyna ◽  
Health Related ◽  
Rare Class ◽  
Rosaceae Family

Hawthorn ( Crataegus sp.) is a traditional medicinal plant, which shows a broad spectrum of health-related effects. Drug preparation is based on material collected from wild growing plants, which usually show variability in their secondary metabolite composition and concentration. Plantations of selected hawthorn genotypes could form the basis of a consistent homogeneous source of top-quality hawthorn drugs. However, as hawthorn is a member of the Rosaceae family, such plantations would be threatened by the bacterial disease fire blight, which currently causes dramatic economic losses in apple and pear orchards. We show that prohexadione-Ca induces the formation in Crataegus monogyna leaves of the rare class of 3-deoxyflavonoids, which are responsible for better fire blight resistance and that the quality and quantity of the health related ingredients are not negatively influenced by prohexadione-Ca treatment.

scholarly journals The Incessant Battle Against Fire Blight in Pears: 30 Years of Challenges and Successes in Managing the Disease in Israel

Plant Disease ◽  
2015 ◽  
Vol 99 (8) ◽  
pp. 1048-1058 ◽  
Author(s):  
Dani Shtienberg ◽  
Shulamit Manulis-Sasson ◽  
Miriam Zilberstaine ◽  
Dov Oppenheim ◽  
Hagai Shwartz
Keyword(s):  
Crucial Role ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Fruit Trees ◽  
Future Perspectives ◽  
Full Understanding ◽  
Pome Fruit ◽  
Local Experience

Fire blight, caused by the bacterium Erwinia amylovora, is the most destructive disease of pears and other pome fruit trees worldwide. The disease was first detected in Israel in 1985, and in the 30 years since, the intensity of fire blight epidemics has varied markedly. During this time, there were two national pandemics: the first between 1994 and 1996 and the second in 2010. In both cases, it was feared that the Israeli pear industry would not recover. National efforts were devoted to combat the problem and after both pandemics the industry survived. In this paper we indicate some unique characteristics that play a crucial role in the epidemiology of the disease under Israeli conditions. We then describe the continual struggle of the Israeli pear industry with fire blight over the last 30 years, elaborating on the two national pandemics and the efforts devoted to cope with them. Finally, we summarize the conclusions derived from our local experience and present our future perspectives regarding fire blight management. The take-home message of the Israeli fire blight story is that the battle against this hazardous disease is neverending. In some years, growers are able to adequately suppress the disease; in others, the pathogen overcomes management efforts and severe outbreaks occur. The latter could be minimized if growers have a full understanding of the management protocols suitable for the conditions and applied them rigorously.

scholarly journals The effect of Regalis® (prohexadione calcium) on the reduction of fire blight (Erwinia amylovora) severity in apple trees

2004 ◽  
Vol 10 (2) ◽  
Author(s):  
P. Sobiczewski ◽  
T. Bubán
Keyword(s):  
Active Ingredient ◽  
Fire Blight ◽  
Shoot Growth ◽  
Control Strategies ◽  
Fruit Trees ◽  
Pome Fruit ◽  
Apple Trees ◽  
Obvious Effect ◽  
One Year ◽  
Prohexadione Calcium

Due to the lack of effective and non-phytotoxic materials for control of the blossom and shoot blight phase of fire blight in pome fruit trees, two novel control strategies have emerged: shoot growth retardation by bioregulators and applying resistance inducer compounds. Prohexadione calcium (ProCa) is the active ingredient of the bioregulator Regalis® registered in several European countries. The reduction of shoot growth elongation is the most obvious effect of ProCa. Furthermore, it causes significant changes in the spectrum of flavonoids and their phenolic precursors, leading to the considerable reduction of susceptibility to fire blight. In Poland, potted one-year-old apple trees of cvs. Gala Must grafted on M.26 and Sampion on M.9 (in 2001) as well as Gala Must on P.60 (in 2002) were treated with Regalis® at a range of concentration of 250, 150 or 150 + 100 ppm, respectively. The inoculation of shoots was made with the strain No.691 of E. amylovora (107 cfu/ml), on the 7th and 21st'day after treatments with Regalis. In Hungary, during the years of 2002 and 2003 one-year-old container grown apple trees of the cvs. Idared/M.9 and Freedom/M.9 were treated with the prohexadione-Ca, the active ingredient of Regalis® 100, 150 or 200 ppm, two weeks before inoculation with the Ea 1 strain of E. amylovora (107 cfu/m1). In Poland, the suppression of fire blight in shoots reached up to 80%, depending on concentration and application time of Regalis®. In Hungary, the effect of prohexadione-Ca treatments, determined by the length of necrotic lesion developed, proved to be better than that of streptomycin used for comparison.

scholarly journals A New Approach to Fire Blight Control: Mycorrhiza

HortScience ◽  
2006 ◽  
Vol 41 (5) ◽  
pp. 1309-1312 ◽  
Author(s):  
Kubilay Kurtulus Bastas ◽  
Aysen Akay ◽  
Salih Maden
Keyword(s):  
Fire Blight ◽  
Shoot Growth ◽  
Glomus Intraradices ◽  
Erwinia Amylovora ◽  
New Approach ◽  
Vesicular Arbuscular ◽  
Pome Fruits ◽  
Shoot Blight ◽  
Apple Cultivars ◽  
And Control

The first outbreak of fire blight incited by Erwinia amylovora (Burr.) Winslow et al. occurred on pome fruits in Turkey in 1985, and it is now one of the most serious diseases of pear, apple, quince, and loquat (Oktem and Benlioglu, 1988). In this study, experiments were conducted in Konya Province to evaluate the efficacy of Glomus intraradices Schenck & Smith vesicular–arbuscular mycorrhiza (VAM) and bactericides for control of the shoot blight phase of fire blight and control of shoot growth on the different apple cultivars (Gala, Red Elstar, Pinova, Jonagored) on M9 rootstock in 2002 to 2003. Streptomycin provided 84.38% to 95.24% and 85.28% to 89.97% disease control in 2002 and 2003, respectively. Copper complex was not so effective against shoot blight phase of the disease, and it reduced disease by 16.18% to 27.75% and 14.48% to 19.06% in 2002 and 2003, respectively. Results of VAM application were encouraging, indicating a reduction of fire blight by Glomus intraradices of between 9.7% and 50.5% in 2002 and between 23.9% and 48.4% in 2003, respectively.

scholarly journals Evaluation of host resistance inducers and conventional products for fire blight management in loquat and quince

2008 ◽  
Vol 88 (3) ◽  
pp. 93-101 ◽  
Author(s):  
Kubilay Kurtulus Bastas ◽  
Salih Maden
Keyword(s):  
Humic Acid ◽  
Disease Severity ◽  
Fire Blight ◽  
Fruit Trees ◽  
Pome Fruit ◽  
Copper Salts ◽  
Harpin Protein ◽  
Shoot Blight ◽  
Resistance Inducers ◽  
Blight Disease

Abstract Fire blight disease is one of the most destructive diseases of pome fruits. Due to the lack of effective, non-phytotoxic and publicly acceptable materials for controlling fire blight in pome fruit trees, new strategies to manage Erwinia amylovora fire blight are being sought. The resistance-inducing compounds prohexadione-Ca, harpin protein and benzothiadiazole (acibenzolar-S-methyl), the fertilizer humic acid, the bactericides streptomycin and copper salts, and combinations of copper with chemicals were evaluated for their ability to control fire blight on quince and loquat cultivars. Prohexadione-Ca was applied at a rate of 125 mg L-1 at two shoot lengths (6-12 cm and 15-20 cm), while benzothiadiazole + metalaxyl (135 mg L-1) and harpin (50 mg L-1) were applied when the shoots measured between 15-20 cm, and again at 30-35 cm. On loquat cv. Cukurgobek, benzothiadiazole + metalaxyl showed about 60% effectiveness. The addition of copper salts reduced the effectiveness of benzothiadiazole + metalaxyl. On quince cultivars, streptomycin (P ≤ 0.05) was the most effective treatment during both years, followed by the harpin protein alone and in combination with copper salts. Prohexadione-Ca, benzothiadiazole + metalaxyl, and harpin protein applications reduced disease severity on inoculated shoots compared with copper and untreated controls. Prohexadione-Ca reduced both shoot length and shoot blight on the two hosts. Humic acid applications were ineffective in controlling fire blight on loquat and quince cultivars. Quince cv. Eşme showed lower disease severity than cv. Ekmek (P ≤ 0.05). The use of resistance-inducing substances during the early phase of shoot growth may offer a means of managing the shoot blight phase of fire blight disease on quince and loquat.

scholarly journals Fire Blight Resistance in Wild Accessions of Malus sieversii

Plant Disease ◽  
2017 ◽  
Vol 101 (10) ◽  
pp. 1738-1745 ◽  
Author(s):  
Julia M. Harshman ◽  
Kate M. Evans ◽  
Haley Allen ◽  
Ryan Potts ◽  
Jade Flamenco ◽  
...  
Keyword(s):  
Fire Blight ◽  
Fruit Size ◽  
Economic Losses ◽  
Bacterial Disease ◽  
Resistance Response ◽  
Washington State University ◽  
Malus Sieversii ◽  
Low Incidence ◽  
Wild Accessions ◽  
And Control

Fire blight (Erwinia amylovora) is a devastating bacterial disease in apple that results in severe economic losses. Epidemics are becoming more common as susceptible cultivars and rootstocks are being planted, and control is becoming more difficult as antibiotic-resistant strains develop. Resistant germplasm currently being utilized by breeding programs tend to have small fruit size and poor flavor characteristics. Malus sieversii, a progenitor species of domestic apple, is notable for its relatively large, palatable fruit and some accessions have been reported to be resistant to fire blight. In this study, nearly 200 accessions of M. sieversii and appropriate controls were inoculated with E. amylovora in both Washington and West Virginia to identify fire blight resistant accessions. Twelve accessions were identified with resistance comparable to highly resistant and resistant controls. Several accessions exhibited a unique resistance response, not previously reported in domestic apple (M. × domestica), characterized by low incidence of infection but high severity once infection was initiated. Several of these M. sieversii accessions will be used as parents in future crosses in the Washington State University apple breeding program.

Sign in / Sign up

Export Citation Format

Share Document