Fig. 1

Botrytis cinerea strains carrying LTR retrotransposons are more aggressive. a LTR retrotransposon phylogenetic relationship of six subfamilies, BcGypsy1-4, BcCopia1-2, identified in the strain B05.10. b LTR retrotransposon BcsRNA abundance of the six subfamilies (BcGypsy1-4, BcCopia1-2) at different time points of S. lycopersicum or A. thaliana host infection (raw data are available at NCBI GEO: GSE45323, GSE45321). c Growth phenotype of the six B. cinerea strains. Scale bars indicate 20 mm. d Genotyping PCR of the six LTR retrotransposon subfamilies in the six B. cinerea strains. e Pathogenicity assay of the six B. cinerea strains on tomato leaves quantifying microlesion area by Trypan Blue staining at 24 hpi. Microlesions in Trypan Blue images were quantified in eight leaf discs per strain as relative grey scale (rel. counts) in relation to the total leaf disc. Scale bars in leaf disc image indicate 1 mm and in higher magnification images 100 μm. f Pathogenicity assay of the six B. cinerea strains on tomato leaves indicating lesion area of > 20 infection sites at 48 hpi. Scale bar indicates 1 cm. For f, infection experiments were repeated three times with similar results. In e and f, a significant difference is indicated by letters and was tested by one-way ANOVA using Tukey HSD test with p < 0.05