Fig.Figure 1(a) The phenotype of non-colonized (Mock) and SA187-colonized (187) 5 d old wheat seedlings after HS treatment at 44°C for 2 h. Data information: All treatments are compared with direct 44°C heat stressed plants. Scale bars correspond to 1 cm. (b) Fresh weight quantification of 9 d old wheat seedlings upon 44°C heat stress (HS) and 22°C normal (NHS) conditions (without and with SA187) after 3 days of recovery at 22°C. Data information: fresh weight measuremts after recovery at 22°C for 4 days. All treatments are compared with direct 44°C heat stressed plants. Plots represent the mean of 3 biological replicates Asterisks indicate a statistical difference based on the Mann-Whitney test (* P < 0.05 ) (c) Plant biomass of wheat obtained upon cultivation with and without SA187 in three consecutive growing seasons of open field agriculture. Data information: All treatments are compared with direct 44°C heat stressed plants. Plots represent the mean of 3 biological replicates n=27, 9 plants/biological repeat for wheat seedlings).Error bars representSE Asterisks indicate a statistical difference based on the Mann-Whitney test (* P < 0.05 ) (d) Experimental scheme of heat experiments and phenotype of Arabidopsis seedlings with and without SA187. Top, plants with Long term acquired thermotolerance (LAT) treatment: 9 d old plants that were grown at 22°C were treated at 37°C for 3 h, then returned to 22°C for 2 d. At d 11, plants were heat stressed at 44°C for 30 min and incubated for recovery at 22°C. Middle, plants with HS treatment: 11 d old plants that were grown at 22°C were treated at 44°C for 30 min and incubated for recovery at 22°C. Bottom, plants with NHS treatment: control plants were grown in parallel at 22°C for 15 d. Data information: Dashed lines indicate the heat acclimation on day 9 at 37°C for 3 h; HS treatment on day 11 at 44°C; sampling time for targeted transcriptome after recovery at 22°C for 1h, 24h, 48h, 72h and 4d: RNA-seq analysis All treatments are compared with direct 44°C heat stressed plants. Plots represent the mean of 3 biological replicates (n=36, 12 plants/biological repeat for Arabidopsis Asterisks indicate a statistical difference based on Student's t-test (* P ≤0.05; ** P ≤ 0.01; *** P ≤ 0.001) (e) Fresh weight of 15 d old plants with and without SA187 under NHS, HS and LAT temperature regimes. Data information: fresh weight, measuremts after recovery at 22°C for 4 days. All treatments are compared with direct 44°C heat stressed plants. Asterisks indicate a statistical difference based on the Mann-Whitney test (* P < 0.05 ) (f) Percent survival of 15 d old plants with and without SA187 under NHS, HS and LAT conditions. Data information: percent survival measuremts after recovery at 22°C for 4 days. For percent survival, plants with green leaves were scored as live plant out of 12 plants for each biological repeat in different temperature treatments. All treatments are compared with direct 44°C heat stressed plants. Plots represent the mean of 3 biological replicates bars representSE Asterisks indicate a statistical difference based on the Mann-Whitney test (* P < 0.05 ) (g) Percentage of bleached and green leaves of 15 d old plants with and without SA187 under NHS, HS and LAT conditions. Data information: bleached/green leaves measuremts after recovery at 22°C for 4 days. For bleached and green leaves, a total no of green and bleached leaves were scored per 12 plants and were devided by 12 to score number of green and bleached leaves/plant. All treatments are compared with direct 44°C heat stressed plants. Plots represent the mean of 3 biological replicates Asterisks indicate a statistical difference based on the Mann-Whitney test (* P < 0.05 )