Article
Ecology
Zhouqi Cui, Regan B. Huntley, Quan Zeng, Blaire Steven
Summary: The study found a link between the apple stigma microbiome and infection byErwinia amylovora, the causal agent of fire blight disease. While a large population of the phytopathogen was established on the stigma, it was not sufficient to predict disease outcome, as only 42% of infected flowers showed symptoms of fire blight.
Article
Biotechnology & Applied Microbiology
Laurin Muller, Denise C. Muller, Sandrine Kammerecker, Marco Fluri, Lukas Neutsch, Mitja Remus Emsermann, Cosima Pelludat
Summary: This study found that apple flowers are not an iron-limiting environment for the fire blight pathogen E. amylovora, and Desferrioxamine (DFO) is an important competition factor for this pathogen in precolonized flowers.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Horticulture
Gulshariya Kairova, Nurzhan Daulet, Maxim Solomadin, Nurlan Sandybayev, Shynggys Orkara, Vyacheslav Beloussov, Nazym Kerimbek, Dilyara Gritsenko, Zagipa Sapakhova
Summary: This study conducted phytopathological evaluation and molecular genetic analysis of 59 apple varieties in different regions of Kazakhstan, finding that 26 varieties showed the highest resistance to fire blight. Interestingly, all 59 apple cultivars had identical genotypes for the 10 markers associated with fire blight resistance.
Article
Biochemistry & Molecular Biology
Zhouqi Cui, Regan B. Huntley, Neil P. Schultes, Kaleem U. Kakar, Ching-Hong Yang, Quan Zeng
Summary: The expression of the type III secretion system (T3SS) in epiphytic Erwinia amylovora cells on stigma and hypanthium of apple flowers varies, with higher expression and promotion of epiphytic growth on stigma surfaces compared to hypanthium surfaces. Pre-culturing E. amylovora cells on stigma enhances T3SS expression and potential for infection, suggesting that T3SS induction during stigmatic colonization may benefit subsequent infection. The expression of T3SS is also influenced by relative humidity, with a higher percentage of T3SS expressing cells under high humidity conditions.
MOLECULAR PLANT-MICROBE INTERACTIONS
(2021)
Article
Plant Sciences
Suzanne M. Slack, Jeffery K. Schachterle, Emma M. Sweeney, Roshni R. Kharadi, Jingyu Peng, Megan Botti-Marino, Leire Bardaji, Emily A. Pochubay, George W. Sundin
Summary: This study tracks the population dynamics of the fire blight pathogen Erwinia amylovora during apple bloom and finds that the population is initially high but decreases after a few days. The study also reveals that population surges, characterized by a 10-fold increase in population within 24 hours, occur on certain days with specific weather conditions such as temperature, wind speed, and humidity.
Article
Microbiology
Anya Schnyder, Leo Eberl, Kirsty Agnoli
Summary: This study investigated the potential of the resident microbiota of apple blossoms in combating plant disease-causing organisms, and identified two candidate biocontrol strains. These strains may already be part of the human diet, making them promising candidates for biocontrol applications.
Article
Plant Sciences
Sarah A. Kostick, Soon Li Teh, Kate M. Evans
Summary: Phenotyping resistance/susceptibility to fire blight is challenging due to the complexity of inheritance and insufficient phenotypic information for breeding decisions. Most resistance alleles have been found in wild germplasm, while reduced susceptibility alleles have been identified in breeding parents. Although DNA-informed breeding for fire blight resistance is attractive, there are currently limited trait-predictive DNA tests available.
Review
Plant Sciences
Quan Zeng, Joanna Pulawska, Jeffrey Schachterle
Summary: This review examines the different infection stages of the fire blight disease caused by Erwinia amylovora, focusing on the early events during the initial infection of flowers and shoot tips. It discusses the production and transfer of inoculum, epiphytic proliferation of the pathogen, entry into the host, and initial proliferation inside the host. Additionally, the review delves into how E. amylovora modulates its virulence expression to induce disease symptoms during these early events.
JOURNAL OF PLANT PATHOLOGY
(2021)
Article
Agriculture, Multidisciplinary
Hyeonheui Ham, Ga-Ram Oh, Dong Suk Park, Yong Hoon Lee
Summary: Fire blight caused by Erwinia amylovora is a devastating disease in apple and pear trees. The continuous use of oxolinic acid has resulted in the emergence of resistant strains. In this study, all isolates collected from South Korea were found to be susceptible to oxolinic acid. However, resistant mutant strains were obtained through exposure experiments, and these mutants exhibited reduced growth and virulence compared to the wild-type. Further research is needed to clarify the mechanisms by which oxolinic acid resistance affects the virulence of this plant pathogen. Continuous monitoring of resistance is necessary to maintain the effectiveness of this bactericide.
PLANT PATHOLOGY JOURNAL
(2022)
Article
Plant Sciences
Suzanne M. Slack, Kellie J. Walters, Cory A. Outwater, George W. Sundin
Summary: The study found that streptomycin and kasugamycin significantly reduced populations of Erwinia amylovora on apple flower stigmas, while oxytetracycline showed more variable results. Additionally, oxytetracycline-treated flowers had significantly higher disease incidence compared to other antibiotic treatments in 2 out of 3 years. The study also revealed that both kasugamycin and oxytetracycline were negatively impacted by solar radiation and temperature, and kasugamycin was susceptible to photodegradation.
Article
Plant Sciences
Jeffrey K. Schachterle, Kristi Gdanetz, Ishani Pandya, George W. Sundin
Summary: The enterobacterial pathogen Erwinia amylovora uses multiple virulence-associated traits to cause fire blight in apple and pear trees. In this study, the transcriptome of E. amylovora during disease progression on apple flowers was characterized using high-throughput sequencing. The results showed that genes related to the type III secretion system and flagellar genes were strongly co-expressed, as well as genes involved in amylovoran biosynthesis and sorbitol utilization. A group of 16 genes with increased and sustained expression throughout disease progression were also identified, and deletion mutants lacking these genes displayed reduced symptom development on apple shoots. These induced genes were also found to be enriched for genes involved in sulphur metabolism and cycling, suggesting their importance in maintaining oxidative homeostasis during apple flower infection.
MOLECULAR PLANT PATHOLOGY
(2022)
Article
Plant Sciences
S. Tianna DuPont, Misbakhul Munir, Kerik Cox, Ken Johnson, Kari Peter, Aina Baro
Summary: Ten experiments were conducted in different states of the United States to evaluate different methods of removing fire blight cankers from apple trees. The removal methods included pruning at different distances, use of a sanitizing agent, and using a stub cut. The results showed that fire blight removal reduced rootstock blight and tree death, and the standard best management practice was branch removal at 30 cm below the cankered tissue with sanitized loppers.
JOURNAL OF PLANT PATHOLOGY
(2023)
Article
Entomology
Matthew Boucher, Rowan Collins, Stephen Hesler, Kerik Cox, Greg Loeb
Summary: The study found that Delia platura flies prefer infected and oozing fruit over uninfected fruit, and this preference diminishes when bacterial ooze is removed. However, the flies do not show a preference between infected saplings and uninfected saplings. Additionally, the volatiles from infected fruit do not attract the flies, indicating that diseased fruit odor is not the reason for their preference.
ENVIRONMENTAL ENTOMOLOGY
(2021)
Article
Agriculture, Multidisciplinary
Duck Kyu Ryu, Mahesh Adhikari, Dong Hyuk Choi, Kyung Jin Jun, Do Hyoung Kim, Chae Ryeong Kim, Min Kyu Kang, Duck Hwan Park
Summary: Fire blight, caused by Erwinia amylovora, is a major bacterial disease in apple and pear trees, resulting in significant economic losses worldwide. This study analyzed the mechanisms and disease severity reduction efficacy of copper-based control agents (CBCAs) against E. amylovora. The results showed that copper oxychloride, copper sulfate basic, and tribasic copper sulfate at 2,000 ppm had significant reduction effects on fire blight.
PLANT PATHOLOGY JOURNAL
(2023)
Article
Plant Sciences
Simone Buehlmann-Schutz, Marius Hodel, Elias Dorfmann, Lukas Vonmetz, Luzia Lussi, Andrea Patocchi
Summary: This study conducted phenotypic and genotypic identification of fire blight resistance in apple using artificial inoculation and molecular markers. The results showed that the major resistance genes FB_MR5 and Fb_E have a significant effect on fire blight resistance, while genotypes carrying FB_F7 exhibited greater variation in resistance levels. No correlation was found between the results of the two phenotyping methods for the tested genotypes, but 11 genotypes showed no significant difference between the results of the two methods. Additionally, flower shedding was identified as an important triggered mechanism for flower resistance to fire blight.
JOURNAL OF PLANT PATHOLOGY
(2023)