Analysis of the antioxidant response of Nicotiana benthamiana to infection with two strains of Pepper mild mottle virus.
The present study was carried out to investigate the role of reactive oxygen species (ROS) metabolism in symptom development and pathogenesis in Nicotiana benthamiana plants upon infection with two strains of Pepper mild mottle virus, the Italian (PMMoV-I) and the Spanish (PMMoV-S) strains. In this host, it has been shown that PMMoV-I is less virulent and plants show the capability to recover 21 d after inoculation. Analyses of oxidative stress biomarkers, ROS-scavenging enzyme activities, and antioxidant compounds were conducted in plants at different post-infection times. Only PMMoV-I stimulated a defence response through: (i) up-regulation of different superoxide dismutase isozymes; (ii) maintenance of adequate levels of three peroxiredoxins (2-Cys Prx, Prx IIC, and Prx IIF); and (iii) adjustments in the glutathione pool to maintain the total glutathione content. Moreover, there was an increase in the level of oxidized glutathione and ascorbate in the recovery phase of PMMoV-I-infected plants. The antioxidant response and the extent of oxidative stress in N. benthamiana plants correlates to: (i) the severity of the symptoms elicited by either strain of PMMoV; and (ii) the high capacity of PMMoV-I-infected plants for symptom recovery and delayed senescence, compared with PMMoV-S-infected plants.
Department of Biochemistry, Molecular and Cellular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas (CSIC) Profesor Albareda 1, 18008 Granada  Spain.
A
A
Hakmaoui
M L
ML
Pérez-Bueno
B
B
García-Fontana
D
D
Camejo
A
A
Jiménez
F
F
Sevilla
M
M
Barón
D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000032:analysis / Q000378:metabolism; D016922:Cellular Senescence; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D005978:Glutathione / Q000032:analysis / Q000378:metabolism; D054884:Host-Pathogen Interactions; D007527:Isoenzymes; D018384:Oxidative Stress / Q000502:physiology; D054464:Peroxiredoxins / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D010935:Plant Diseases / Q000821:virology*; D018515:Plant Leaves / Q000201:enzymology / Q000502:physiology / Q000821:virology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D014026:Nicotiana / Q000201:enzymology / Q000502:physiology* / Q000821:virology; D017898:Tobamovirus / Q000472:pathogenicity*; D015854:Up-Regulation; D014774:Virulence
D000975:Antioxidants; D007527:Isoenzymes; D045332:Photosystem II Protein Complex; D017382:Reactive Oxygen Species; D054464:Peroxiredoxins; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid