Exploring the realm of unknown induced proteins by salicylic acid and their role in resistance against biotrophic pathogens
M. PEREIRA MENDES (1), R. Hickman (1), C. Pieterse (1), S. van Wees (1), M. van Verk (2) (1) Plant-Microbe Interactions, Dept. of Biology, Utrecht University, The Netherlands, Netherlands; (2) Plant-Microbe Interactions/Bioinformatics, Dept. of Biology, Utrecht University, The Netherlands, Netherlands

Plants are constantly under threat of various pathogens and herbivorous insects. To defend themselves, plants have evolved a sophisticated defense system. In Arabidopsis this defense mechanism is primarily regulated by two hormones; salicylic acid (SA) and jasmonic acid (JA). To advance our understanding of the SA defense-signaling cascade we performed a RNA-Seq time series of SA treated plants. The data revealed a huge number of differentially expressed (DE) genes (>8500), of which 666 have no known annotated for putative function. To avoid missing any potentially very interesting genes we used the tool OrthoMCL to determine groups of protein sequences among the DE that are very similar on amino acid level. This has resulted in a set of eight very short (71-75 AA) proteins that are almost identical in their amino acid composition. The expression profiles of these peptides in responses to SA are moderately affected. However, almost all of them are both rapid and highly induced by biotrophic pathogens like Pseudomonas. Currently we are finalizing the generation of individual overexpression lines and RNAi lines encompassing all genes, in order to check their influence on SA signaling and resistance against biotrophic pathogens. Overall these results indicate that there are still a huge number of unknown genes that might play very important roles in SA signaling and biotrophic pathogen perception, providing a new source for breeding and developing new resistance traits.

Abstract Number: P16-465
Session Type: Poster