Advanced Copper Composites Against Copper-TolerantXanthomonas perforansand Tomato Bacterial Spot

Abstract

Bacterial spot, caused by Xanthomonas spp., is a widespread and damaging bacterial disease of tomato (Solanum lycopersicum). For disease management, growers rely on copper bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study evaluated the antibacterial activity of the new copper composites core-shell copper (CS-Cu), multivalent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu) as potential alternatives to commercially available micron-sized copper bactericides for controlling copper-tolerant Xanthomonas perforans. In vitro, metallic copper from CS-Cu and FQ-Cu at 100 μg/ml killed the copper-tolerant X. perforans strain within 1 h of exposure. In contrast, none of the micron-sized copper rates (100 to 1,000 μg/ml) from Kocide 3000 significantly reduced copper-tolerant X. perforans populations after 48 h of exposure compared with the water control (P < 0.05). All copper-based treatments killed the copper-sensitive X. perforans strain within 1 h. Greenhouse studies demonstrated that all copper composites significantly reduced bacterial spot disease severity when compared with copper-mancozeb and water controls (P < 0.05). Although there was no significant impact on yield, copper composites significantly reduced disease severity when compared with water controls, using 80% less metallic copper in comparison with copper-mancozeb in field studies (P < 0.05). This study highlights the discovery that copper composites have the potential to manage copper-tolerant X. perforans and tomato bacterial spot.

Copper ions suppress abscisic acid biosynthesis to enhance defence against Phytophthora infestans in potato

“…Currently, CBACs, including Bordeaux mixture, have the sixth highest sales volume in the world. They are still effective in controlling plant diseases, even those caused by copper‐tolerant pathogens (Cha and Cooksey, ; Strayer‐Scherer et al , ). Hence, we hypothesized that Cu 2+ not only has toxic activity but also induces defence responses in plants.…”

“…It is normally thought that CBACs have two tiers of function: to release Cu 2+ , which inhibits the activity of enzymes in fungal spores to prevent germination (Pscheidt and Ocamb, ), and to provide a protective barrier against plant pathogens by covering plant surfaces (Lamichhane et al , ). After long‐time application, numerous copper‐tolerant strains have been identified in the field; however, CBACs application still has the ability to manage copper‐tolerant strains and reduce disease severity (Strayer‐Scherer et al , ). The two‐tiered protective model is hardly adequate to explain the resistance of copper‐tolerant strains.…”

From visual estimates to fully automated sensor-based measurements of plant disease severity: status and challenges for improving accuracy

“…Quantitative ordinal scales may have equal or unequal intervals (Horsfall and Heuberger 1942;Horsfall and Barratt 1945;Hunter and Roberts 1978). The Horsfall-Barratt scale (HB, Horsfall and Barratt 1945) has been widely used (Table 1; Haynes et al 2002;Miyasaka et al 2012;Jones and Stansly 2014;Rioux et al 2017;Kutcher et al 2018;Strayer-Scherer et al 2018). The US Forestry Service uses it to assess ozone injury (https://www.nrs.fs.…”

Fengycins From Bacillus amyloliquefaciens MEP218 Exhibit Antibacterial Activity by Producing Alterations on the Cell Surface of the Pathogens Xanthomonas axonopodis pv. vesicatoria and Pseudomonas aeruginosa PA01

“…It is estimated that 4 to 5% of the genome of the strains belonging to the B. subtilis group is dedicated to the production of antimicrobial molecules, which are typically antimicrobial peptides with diverse chemical structures and moieties. Bioactive volatile metabolites and polyketides are also produced by the B. subtilis group (Stein, 2005;Caulier et al, 2019). These characteristics give Bacillus subtilis group species great competitive advantages and make these attractive microorganisms for the industrial production of biopesticides and antibiotics (Borriss, 2011;Wu et al, 2015;Fira et al, 2018;Rabbee et al, 2019).…”

“…Xav is a phytopathogen that has acquired resistance to the most commonly used control methods. The emergence of copper-tolerant Xanthomonas strains constitutes a serious problem for farmers (Potnis et al, 2015;Strayer-Scherer et al, 2018). P. aeruginosa is an opportunistic pathogen that, due to its metabolic versatility, is able to colonize several niches, being a serious problem in hospitalized patients and a leading cause of morbidity and mortality in patients with cystic fibrosis or immunocompromised.…”