Plum pox virus (PPV, sharka disease) is a serious limiting factor for temperate fruit production (mainly apricots, plums, prunes and peaches) in those areas that are affected. Studies with several plant-virus systems demonstrated lower photosynthetic electron transport rates in infected plants, essentially in the PS II level. On the other hand, hydrogen peroxide has been postulated to play multiple functions in plant defence against pathogens. In previous work carried out using crude extracts from apricot leaves, an important role for H2O2 in the response to PPV has been suggested. However, no information about the effect of PPV infection on antioxidant enzymes at the subcellular level in natural woody hosts is available. In this study the effect of PPV infection on the rates of photosynthesis and the response of some antioxidant enzymes to PPV infection was studied in plants of ‘GF305 peach cultivar, characterized by its great susceptibility to this virus. The presence of PPV particles in cells from infected plant was observed by electron microscopy. PPV infection did not produce important changes in PS II efficiency (Fv/Fm) in peach leaves, at least after two months during the first infection cycle. An increase in APX and a significant decrease in SOD were observed in both soluble fractions and chloroplasts from inoculated peaches. However, no significant changes were produced in catalase activity measured in soluble fractions. The possible role of H2O2 in the response of plants to PPV is discussed.

En: XIX International Symposium on Virus and Virus-like Diseases of Temperate Fruit Crops - Fruit Tree Diseases, Valencia, (Spain). Editor: G. Llácer.

Peer reviewed