Many Australian pepper producers have reported poor control of bacterial spot of pepper (caused by Xanthomonas campestris pv. vesicatoria) despite using copper bactericides at recommended rates. This prompted us to investigate whether copper-tolerant strains of the pathogen are present in Australia and whether they are a contributing factor to poor control. We screened strains of X. campestris pv. vesicatoria in the laboratory, in broths containing different concentrations of CuSO, and established the maximum copper concentration at which each strain could grow. About one in four strains (75 total) collected between 1999 and 2000 tolerated ≥1.0 mM CuSO and could be considered copper tolerant. Only one strain (of 12) collected before 1987 could tolerate 1.0 mM, and comparison of the two populations by fitting regression models revealed that the mortality of strains in the two populations differed significantly across all concentrations of copper. It was necessary to apply higher rates of copper to strains collected between 1999 and 2000 to achieve mortality levels equivalent to those in the older population. This is strong evidence that the prevalence of copper-tolerant strains has increased in Australian populations. We also assessed whether copper-tolerant strains may increase substantially in a field population of X. campestris pv. vesicatoria when copper is repeatedly sprayed. In the field, the proportion of copper-tolerant strains increased after 12 weekly sprays of copper, and they were very prevalent in the population after 21 sprays. This is the first report of copper tolerance in Australian populations of X. campestris pv. vesicatoria.
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http://dx.doi.org/10.1094/PDIS.2004.88.9.921 | DOI Listing |
Front Microbiol
December 2024
Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation, College of Biology, Hunan University, Changsha, China.
Bacterial diseases pose significant threats to agriculture and natural ecosystems, causing substantial crop losses and impacting food security. Until now, there has been a less efficient control strategy against some bacterial diseases such as bacterial wilt, caused by . In this study, we screened a library of 58 microorganism-derived natural products for their antibacterial activity against .
View Article and Find Full Text PDFMol Plant Pathol
December 2024
Plant Metabolism Group, Leibniz-Institute of Vegetable and Ornamental Crops (IGZ), Großbeeren, Germany.
Plant Pathol J
August 2024
Laboratory of Horticultural Crop Protection, Division of Horticultural Science, Gyeongsang National University, Jinju 52725, Korea.
Plant Methods
July 2024
Department of Horticulture, Division of Applied Life Science (BK21 Four Program), Institute of Agriculture & Life Science, Gyeongsang National University, Jinju, 52828, Republic of Korea.
Background: Dual RNA sequencing is a powerful tool that enables a comprehensive understanding of the molecular dynamics underlying plant-microbe interactions. RNA sequencing (RNA-seq) poses technical hurdles in the transcriptional analysis of plant-bacterial interactions, especially in bacterial transcriptomics, owing to the presence of abundant ribosomal RNA (rRNA), which potentially limits the coverage of essential transcripts. Therefore, to achieve cost-effective and comprehensive sequencing of the bacterial transcriptome, it is imperative to devise efficient methods for eliminating rRNA and enhancing the proportion of bacterial mRNA.
View Article and Find Full Text PDFBiology (Basel)
May 2024
Plant Pathology Department, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt.
Tomato bacterial spots, caused by pv. () and (), as well as bacterial specks, caused by two strains of pv. ( and ), represent significant threats to tomato production in the El-Sharkia governorate, often resulting in substantial yield losses.
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