<i>Sorghum bicolor</i> prioritizes the recovery of its photosynthetic activity when re‐watered after severe drought stress, while manages to preserve it under elevated <scp>CO<sub>2</sub></scp> and drought
Xabier Simón Martínez‐Goñi, Anabel Robredo, Usue Pérez‐López, Alberto Muñoz‐Rueda, Amaia Mena‐Petite
Abstract
Abstract Understanding plant response and resilience to drought under a high CO 2 environment will be crucial to ensure crop production in the future. Sorghum bicolor is a C 4 plant that resists drought better than other crops, which could make it a good alternative to be grown under future climatic conditions. Here, we analyse the physiological response of sorghum under 350 ppm CO 2 (aCO 2 ) or 700 ppm CO 2 (eCO 2 ) with drought (D) or without drought (WW) for 9, 13 and 16 days; as well as its resilience under long (R1: 9D + 7R) or short (R2: 13D + 3R) recovery treatments. Sorghum showed elevated rates of gs under aCO 2 and WW, which resulted in a significant decrease in Ψ w , gs , E , Φ PSII , F v ’/F m ′ when exposed to drought. Consequently, A was greatly decreased. When re‐watered, both re‐watering treatments prioritized A recovery by restoring photosynthetic machinery under aCO 2 , whereas under eCO 2 plants required little recovery since plant were hardly affected by drought. However, sorghum growth rate for aboveground organs did not reach control values, indicating a slower long‐term recovery. Overall, these results provide information about the resilience of sorghum and its utility as a suitable candidate for the drought episodes of the future.