Rcr3 and Pip1 are paralogous secreted papain-like proteases of tomato. Both proteases are inhibited by Avr2 from the fungal pathogen Cladosporium fulvum, but only Rcr3 acts as a co-receptor for Avr2 recognition by the tomato Cf-2 immune receptor [ 1, 2, 3 and 4]. Here, we show that Pip1-depleted tomato plants are hyper-susceptible to fungal, bacterial, and oomycete plant pathogens, demonstrating that Pip1 is an important broad-range immune protease. By contrast, in the absence of Cf-2, Rcr3 depletion does not affect fungal and bacterial infection levels but causes increased susceptibility only to the oomycete pathogen Phytophthora infestans. Rcr3 and Pip1 reside on a genetic locus that evolved over 36 million years ago. These proteins differ in surface-exposed residues outside the substrate-binding groove, and Pip1 is 5- to 10-fold more abundant than Rcr3. We propose a model in which Rcr3 and Pip1 diverged functionally upon gene duplication, possibly driven by an arms race with pathogen-derived inhibitors or by coevolution with the Cf-2 immune receptor detecting inhibitors of Rcr3, but not of Pip1.
- cf-2-dependent disease resistance
- pathogen effectors
- transcription factors
- provides insights
- genome sequence
Ilyas, M., Hörger, A. C., Bozkurt, T. O., van den Burg, H. A., Kaschani, F., Kaiser, M., Belhaj, K., Smoker, M., Joosten, M., Kamoun, S., & van der Hoorn, R. A. L. (2015). Functional Divergence of Two Secreted Immune Proteases of Tomato. Current Biology, 25(17), 2300-2306. https://doi.org/10.1016/j.cub.2015.07.030