Tolerance to ozone might impose restrictions to plant disease management in tomato

• Published in: Plant biology (Stuttgart, Germany) Germany), 2020-01, Vol.22 (1), p.47-54
• Main Authors: Romero, A. M., Menéndez, A. I., Folcia, A. M., Martínez‐Ghersa, M. A., Sparks, J.
• Format: Article
• Language: English
• Subjects: Air pollution; Air pollution effects; Antioxidants; Bacterial disease; Bacterial diseases; Bacterial Physiological Phenomena - drug effects; Chemical defense; Cultivars; Disease control; Disease management; Food production; Host-Pathogen Interactions - drug effects; Lycopersicon esculentum - drug effects; Lycopersicon esculentum - microbiology; Organic chemistry; Ozone; Ozone - toxicity; Plant diseases; Plant Diseases - prevention & control; Plant growth; Plant Leaves - microbiology; Plant tissues; plant–pathogen interactions; Pollutants; Reactive oxygen species; Tomatoes; tropospheric ozone; Xanthomonas vesicatoria
• ISSN: 1435-8603; 1438-8677
• DOI: 10.1111/plb.13041

Tropospheric ozone (O3) is considered a major air pollutant having negative effects on plant growth and productivity. Background concentrations are expected to rise in several regions of the world in the next 50 years, affecting plant responses to diseases, thus requiring new management strategies for food production. The effects of elevated O3 on the severity of a bacterial disease, and the effectiveness of a chemical defence inducer, were examined in two cultivars of tomato, Roma and Moneymaker, which present different tolerance to this pollutant. The two cultivars differ in their ability to produce and accumulate reactive oxygen species (ROS) in leaf tissues. Tomato plants were challenged with a strain of Xanthomonas vesicatoria, Xv9, which is pathogenic on tomato. Ozone consistently increased severity of the disease by over 40% in both cultivars. In the more tolerant cultivar, O3 pollution increased disease intensity, even after applying a commercially available product to enhance resistance (acibenzolar‐S‐methyl, BTH). In the more susceptible cultivar, level of disease attained depended on the oxidative balance that resulted from other stress factors. The antioxidant capacity of the plant at the time of infection was relevant for controlling development of the disease. Our results suggest that development of O3 tolerance in commercial crops might impose a penalty cost in terms of disease management under projected higher O3 concentrations. Development of ozone tolerance in commercial crops might impose a penalty cost in terms of disease management, since the oxidative status of a plant at the time of infection is crucial for the progression of a bacterial disease.