Fig. 1.

Schema of the temperature, water deficit, and low nitrogen regimes tested in the 13 experiments analyzed in this study. In EXP1994, EXP1995, and EXP2000, before the beginning of setpoint temperature, plants were grown at 18/10 °C (day/night temperature) during the temperature control period. In EXP2000, before temperature regimes changed to 18/10 °C, plants were grown at Out–5°C. Abbreviations and symbols: CK, control treatment; eCO₂, elevated air CO₂ concentration; Out°C, outside ambient temperature; Out+5°C, outside ambient temperature plus 5 °C; Out+10°C, outside ambient temperature plus 10 °C; Out–5°C, outside ambient temperature minus 5 °C; HS, heat shock; WW, well-watered; WD, water deficit; LN, low nitrogen. HS1, HS2, HS12, and HS3 represent heat shocks during the early grain-filling period, the mid grain-filling period, during both early and mid grain-filling periods, and during the late grain-filling period, respectively. WD1, WD2, WD12, and WD3 represent water deficit stress occurring during the pre-anthesis period, the post-anthesis period, both pre- and post-anthesis periods, and during the late grain-filling period, respectively. Details and codes for experiments and treatments on the left are defined in Supplementary Table S1.