Implication of peroxidase activity in development of healthy and PPV-infected micropropagated GF305 peach plants

Abstract

In this work, we describe the micropropagation of PPV-infected GF305 peach plants for their use as a continuous source of PPV inoculums. We observed that PPV was maintained in each sub-culture as well as in the complete micropropagation cycle, including shoot proliferation, rooting and acclimatization to ex vitro conditions. We assayed the addition of fructose and ferulic acid to the multiplication media, to improve the quality and vigour of shoots. This increased the growth of explants and this effect was correlated with a reduction in POX activity, suggesting the possible participation of POX in the growth regulation of micropropagated GF305 shoots. In general, PPV-infected explants did not show evident Sharka symptoms under in vitro conditions, but some explants showed the typical interveinal chlorosis produced by PPV. However, all the PPV-acclimated plants developed normal Sharka symptoms. The data shows that shoot cultures can be used as a reservoir of PPV inoculums as well as to study different metabolic response of healthy and PPV-infected plantlets. In addition, this strategy could serve as a secure and constant source of both healthy and virus-infected plants for other molecular and biological studies.