Source: CropBiotech Update

Plants respond to attack by invading pathogens through a complex network of signals that activate defense mechanisms. Scientists are interested in plant-pathogen interactions, as they can provide a glimpse into how the plant immune system works, which, in turn, can contribute to further studies on engineering pathogen resistance into plants.

One such pathogen, potato virus Y, causes potato tuber necrotic disease in sensitive cultivars. Studies have hitherto been unable to track the overall changes arising from the interaction between potato plants and the virus. Scientists from research institutions in Slovenia and the Netherlands, however, have been able to determine the “Potato virus Y induced changes in the gene expression of potato (Solanum tuberosum L.).” Their work is published in the latest issue of Physiological and Molecular Plant Pathology.

Scientists used the highly sensitive potato cultivar Igor, which they infected with Potato Virus Y. Through subjective hybridization, cDNA microarrays, and real-time PCR, they monitored gene expression in both infected and uninfected plants. After analyzing their results, they found that 175 genes were expressed in high amounts due to pathogen stress. These genes coded for heat shock proteins, catalase 1, ?-1,3-glucanase, wound inducing gene, and genes involved in photosynthesis, suggesting that these genes may play a role in the susceptible potato–potato Virus Y interaction. The scientists, however, were not able to assign function to about 33% of the isolated genes; and, when they compared the expression profile to existing plant-virus interaction data, found that different sets of genes were activated not only in different plant hosts, but in different development stages. Only studies on a wide range of host–virus combinations can lead to identification of general features in plant–virus interactions, the authors wrote.

Because this study has provided important insights into the susceptible potato–virus interaction at the level of gene expression, scientists are better equipped to find more means by which to engineer Potato Virus Y resistance in potatoes.

Subscribers to the journal can access the complete article at http://dx.doi.org/10.1016/j.pmpp.2006.02.005

Source: Science Direct

Potato virus Y induced changes in the gene expression of potato (Solanum tuberosum L.)
Maruša Pompe-Novak, Kristina Gruden, Špela Baebler, Hana Krečič-Stres, Maja Kovač, Maarten Jongsma and Maja Ravnikar
National Institute of Biology, Večna pot 111, 1000 Ljubljana, Slovenia
Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
Plant Research International, Postbus 16, 6700 AA Wageningen, The Netherlands

Abstract

The tuber necrotic strain of Potato virus Y (PVY^NTN) causes potato tuber necrotic ringspot disease in sensitive potato cultivars. Gene expression in the disease response of the susceptible potato (Solanum tuberosum L.) cultivar Igor was investigated at different times after infection, using subtractive hybridization, cDNA microarrays and real-time PCR. The most pronounced change in the expression pattern of functionally diverse groups of genes was detected in systemically infected leaves 14 days after inoculation, and in leaves of plants grown from infected tubers. The expression of several stress-related genes during the infection process, including those for heat shock proteins, catalase 1, β-1,3-glucanase, wound inducing gene, and genes involved in photosynthesis, suggests their role in the susceptible potato–PVY^NTN interaction.