Response of antioxidative enzymes to plum pox virus in two apricot cultivars

Abstract

Recent evidence has indicated that activated oxygen species (AOS) may function as molecular signals in the induction of defence genes. In the present work, the response of antioxidative enzymes to the plum pox virus (PPV) was examined in two apricot (Prunus armeniaca L.) cultivars, which behaved differently against PPV infection. In the inoculated resistant cultivar (Goldrich), a decrease in catalase (CAT) as well as an increase in total superoxide dismutase (SOD) and dehydroascorbate reductase (DHAR) activities were observed. Ascorbate peroxidase (APX), glutathione reductase (GR) and monodehydroascorbate reductase (MDHAR) did not change significantly in relation to non-inoculated (control) plants. In the susceptible cultivar (Real Fino), inoculation with PPV brought about a decrease in CAT, SOD and GR, whereas a rise in APX, MDHAR and DHAR activities was found in comparison to non-inoculated (control) plants. Apricot leaves contain only CuZn-SOD isozymes, which responded differently to PPV depending on the cultivar. Goldrich leaves contained 6 SODs and both SOD 1 and SOD 2 increased in the inoculated plants. In leaves from Real Fino, 5 SODs were detected and only SOD 5 was increased in inoculated plants. The different behaviour of SODs (H2O2-generating enzymes) and APX (an H2O2-remover enzyme) in both cultivars suggests an important role for H2O2 in the response to PPV of the resistant cultivar, in which no change in APX activity was observed. This result also points to further studies in order to determine if an alternative H2O2-scavenging mechanism takes place in the resistant apricot cultivar exposed to PPV. On the other hand, the ability of the inoculated resistant cultivar to induce SOD 1 and SOD 2 as well as the important increase of DHAR seems to suggest a relationship between these activities and resistance to PPV. This is the first report about the effect of PPV infection on the antioxidative enzymes of apricot plants. It opens the way for the further studies, which are necessary for a better understanding of the role of antioxidative processes in viral infection by PPV in apricot plants.

Biochemical Characterization of Compatible Plant Virus Interaction: A Case Study with Bunchy Top Virus-Banana Host-Pathosystem

“…In these cells, that are not able to trigger a response to stop pathogens, the APX increase limits the propagation of oxidative processes allowing cells to maintain their viability, a condition required for the penetration of biotrophic powdery mildew in plant tissues (Burhenne and Gregersen, 2000). This up-regulation of APX confirms previous results reporting an increase in APX activity during successful infection of barley leaves by biotrophic compatible pathogens (El-Zahaby et al, 1995;Vanacker et al, 1998;Kuzniak and Sklodowska, 1999) and has also been reported to occur in leaves of susceptible apricot infected by Plum pox virus (Hernandez et al, 2001). …”

Antioxidant Systems and O2 .−/H2O2 Production in the Apoplast of Pea Leaves. Its Relation with Salt-Induced Necrotic Lesions in Minor Veins

“…Likewise, it is known that the above-described elicitors are capable of inducing the synthesis of activated oxygen species (AOS) in the apoplast of plant cells and also modulate the level of cellular antioxidants as well as the levels of apoplastic antioxidant enzymes (Luwe, 1996;Ranieri et al, 1996;Blinda et al, 1997;Thordal-Christensen et al, 1997;Schraudner et al, 1998;Vanacker et al, 1998aVanacker et al, , 1998bPiqueras et al, 1999;Hernández et al, 2001). However, little is known about the capacity of salt to induce the synthesis of AOS in the apoplast and, in this case, the role played by apoplastic antioxidants.…”

Differentially expressed genes in healthy and plum pox virus-infected Nicotiana benthamiana plants

“…Enhanced APX activity has been found also in virus-infected plants (e. g. citrus tristeza virus in Mexican lime; Pérez-Clemente et al, 2015). Interestingly, APX activity was induced by PPV infection only in a susceptible (contrary to a resistant) apricot cultivar (Hernández et al, 2001).…”