Fig. 4

Assessment of bacterial effects on host plant thermotolerance. Hydroponically grown Arabidopsis seedlings were inoculated with individual strains of Variovorax spp. and co-cultured for 7 days prior to heat shock at 45 °C for 14 min. After 4 days of recovery, plants were harvested to measure chlorophyll content. Box plots represent relative chlorophyll content compared to no heat shock (NHS) control plants. Box plots display the 25th – 75th percentiles with the median (horizontal line) (n = 5–6 wells, except NHS and Mock of which n = 12, with ca. 10 seedlings in each well, outliers which lie outside of 1.5 times the interquartile range above the upper quartile and below the lower quartile are removed). Asterisks denote significant differences compared to mock control (Fisher’s LSD, P < 0.05)