Early production of reactive oxygen species coupled with an efficient antioxidant system play a role in potato resistance to late blight

Abstract

The association between reactive oxygen species (ROS) production and potato resistance to the hemibiotrophic pathogen Phytophthora infestans is poorly understood. In this study, the concentrations of hydrogen peroxide (H 2 O 2), malondialdehyde (MDA), and soluble phenolics, as well as the activities of superoxide dismutase, catalase, and ascorbate peroxidase were measured during the early biotrophic and late necrotrophic stages of P. infestans infection on resistant and susceptible 'Ovatio' and 'Bintje' potato plants, respectively. Pathogen biomass was examined using semi-quantitative RT-PCR. Late blight (LB) severity was also evaluated. The LB severity in Ovatio was lower than that in Bintje, irrespective of the evaluation time. Moreover, in both cultivars, various biochemical defense responses occurred following pathogen infection. The susceptible cultivar activated defense responses at the later pathogen infection stages, resulting in higher concentrations of H 2 O 2 and greater MDA content, with lower activity of antioxidant enzymes and phenolic content. These responses were accompanied by the necrotrophic phase, leading to extensive necrotic lesions on leaves. In contrast, fast hypersensitive-like lesions, an early peak in H 2 O 2 concentration, low cell membrane integrity during the biotrophic phase, and a more efficient antioxidative system effectively restricted pathogen colonization before the transition to the necrotrophic phase in the resistant cultivar. These results suggest that LB resistance or susceptibility is regulated by a balance between the induction of ROS/antioxidants (intensity and timing) and the trophic phase of P. infestans.

Levels of physiological activity of antioxidant enzymes in potatoes (S. tuberosum L.) when infected PVS virus

“…For example El. Komy, M.H., Saleh showed that potato plants in response to a biotic stressor sharply increase the level of SOD activity in resistant varieties [26].…”

Potato Late Blight Severity and Epidemic Period Prediction Based on Vis/NIR Spectroscopy

“…The change in POD activity is related to the defense system in the plant. The decline in POD activity at the beginning of the disease is due to the disruption of the metabolic balance in the plant by the pathogen, and the addition afterward is due to the production of large amounts of POD enzymes in the plant to remove the reactive oxygen damage caused by the pathogen [43,44]. In addition, the rate of changes in physicochemical values at different temperature conditions was not the same.…”

Transcriptome responses to Ralstonia solanacearum infection in the tetraploid potato

“…The quick generation of ROS has been associated with the innate immunity of plants (Saeed andTrujillo 2022, Kobayashi et al 2012). Several ndings indicate that the resistance or susceptibility of late blight may be governed by the equilibrium between the activation of ROS/antioxidants (both in terms of intensity and timing) and the trophic stage of P. infestans (El_Komy et al 2020). To gain insights into the biochemical factors underlying tomato plant's response to R. s, it is crucial to investigate ROS generation, antioxidative mechanisms, and cell wall reinforcement in two distinct cultivars, Arka Meghali and BT-10, the results suggest that enhanced ROS production, along with an e cient antioxidative system, reduced lipid peroxidation rate, and increased lignin deposition in the cell wall, could play a key role in the resistance of tomato plants against R. s (Mandal, Das and Mishra 2011).…”