Redundancy in Plant Defense Figure 5. Interaction phenotypes of H. arabidopsidis biotype Emco5 expressing Atr8 with RPP8 eds1-2 nahG or RPP8 eds1-2 sid2-1 plants. (A) Whole leaf pictures showing growth of Emco5 on the cotyledons from indicated genotypes. All genotypes were in the Ler background. Cotyledons were photographed 10 days after inoculation. (B) Trypan blue stained leaf showing microscopic HR on Ler and Ler nahG leaves, and trailing necrosis on eds1-2 and eds1-2 nahG leaves (scale bars, 270 microns). Both high (1006) and low magnification (1006) images of eds1-2 nahG leaf are shown. Pathogen inoculations were carried out in F2, F3, and F4 generations with consistent results. The F2 plants showing wt genotype at the mutant locus were resistant to pathogen infection (data not shown). (C) Quantification of pathogen growth on RPP8 EDS1, RPP8 eds1-2 and RPP8 eds1-2 nahG plants. Approximately, 40–60 cotyledons were assayed for each genotype. Asterisks indicate absence of spores. All genotypes were in the Ler background. (D) Quantification of pathogen growth on RPP8 sid2, RPP8 eds1-2, and RPP8 eds1-2 sid2-1 plants. All genotypes were in the ssi2 background. Approximately, 40–60 cotyledons were assayed for each genotype. Asterisks indicate absence of spores. doi:10.1371/journal.pgen.1000545.g005 PLoS Genetics | www.plosgenetics.org 9 July 2009 | Volume 5 | Issue 7 | e1000545