Resistance of strawberries to Xanthomonas fragariae induced by aloe polysaccharides and essential oils nanoemulsions is associated with phenolic metabolism and stomata closure

• Published in: Australasian plant pathology Vol. 51; no. 3; pp. 305 - 314
• Main Authors: Luiz, Caroline, Caires, Nilmara Pereira, de Aguiar, Tarsis, Blainski, Juliane Mendes Lemos, da Silva Behs, Julia, Coqueiro, Danila Souza Oliveira, Piero, Robson Marcelo Di
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 2022; Springer Nature B.V
• Subjects: Accumulation; Agriculture; Aloe; Berries; Biomedical and Life Sciences; Chemical control; Cultivars; Disease control; Ecology; Entomology; Essential oils; Fluorescence microscopy; Gas analyzers; Gas exchange; Infrared analysis; Inoculation; Leafspot; Leaves; Life Sciences; Lignin; Metabolism; Nanoemulsions; Oils & fats; Original Research Article; Palm oil; Phenolic compounds; Phenols; Plant Pathology; Plant Sciences; Polysaccharides; Saccharides; Spectrophotometry; Stomata; Strawberries; Transpiration; Xanthomonas fragariae; Phenolic compounds; Nanoemulsion; Leaf spot; Bacterial disease
• ISSN: 0815-3191; 1448-6032
• DOI: 10.1007/s13313-022-00856-x

The angular leaf spot is the main bacteriosis in the strawberry crop and the genetic and chemical control measures do not have uniform responses for disease management. Aloe polysaccharides and essential oils nanoemulsions are potential inducers of resistance against Xanthomonas fragariae . In the current study, the effect of these products was evaluated on the disease severity, on the accumulation of phenolic by fluorescence microscopy, in the lignin formation by spectrophotometry, and in the leaf gas exchange by infrared gas analyzer in Albion and San Andreas cultivars. In both cultivars there was significant disease control promoted by the products, with reduction higher than 96% compared to control. In the moderately susceptible cultivar, San Andreas, the application of aloe polysaccharides or emulsions promoted the accumulation of phenolic compounds and lignin in the plants after their inoculation with X. fragariae . In the Albion cultivar, highly susceptible, bacterial inoculation caused stomata opening, inferred by increases in stomata conductance, and transpiration rate. These processes were reversed in plants previously treated with nanoemulsion containing palm oil. Our study suggests that the strawberries cultivars respond differently to the elicitors, where phenolic metabolism and stomata closure play an important role in defense responses of San Andreas and Albion against X. fragariae , respectively.