Inhibitory activity of secondary metabolites from BTH- and BABA-treated pea against Uromyces pisi infection

Abstract

Póster presentado en la First Legume Society Conference, celebrada en Novi Sad (Serbia) del 9 al 11 de mayo de 2013.Pea rust (Uromyces pisi) is a widespread disease of pea (Pisum sativum) worldwide. We previously reported induction of systemic acquired resistance to rust infection in pea by exogenous applications of BTH and BABA based on a reduction of appressorium formation, as well as growth of infection hyphae and haustorium formation. This was related to activation of the phenylpropanoid pathway increasing levels of total phenolic compounds. In this work we attempted to discern by high performance liquid chromatography the particular phenolic compounds involved in reducing rust infection in pea following BABA and BTH induction of resistance. For the experiment we used cv. Messire, susceptible, and PI347321 characterized with partial resistance to U. pisi no associated with host cell death. Following SAR in ducer application we observed an increase in the amount of total but a lso in the excreted fraction of coumarins, particularly scopoletin, medicarpin and pisatin although the nature and proportion of the particular coumarins differed between treatments. Interestingly BTH treatment was more actively related with phenolic accumulation than BABA suggest ing differing pathways for the induction of resistance. In addition, exogenous application of scopoletin, medicarpin and pisatin to the leaves lead to a reduction of the different fungal growth stages. Thus, the data suggested that BTH and BABA had an effect on the production and secret ion of particular phytoalexins and other unknown fungitoxic compounds to the leaf surface that hampered pre and post penetration fungal stages. Further studies are being carried out to determine the nature of the unknown phenolic compounds induced by BABA and BTH.Peer Reviewe