Fig. 10.

A model depicting ‘differential transpiration’ during a combination of water deficit (WD) and heat stress (HS). Control plants (left) conduct transpiration through open stomata on their leaves and flowers. In response to WD, plants (second from left) close their stomata on leaves and flowers and suppress transpiration. During HS, plants (third from left) keep their stomata on leaves and flowers open and maintain transpiration. By contrast, during a combination of WD and HS, plants (right) keep their stomata on flowers open, while closing their stomata on leaves. The opening of stomata on flowers from plants subjected to HS or a combination of WD + HS is proposed to result from an enhanced rate of abscisic acid (ABA) degradation that specifically occurs in flowers from plants grown under these conditions. The strategy of differential transpiration allows plants subjected to the stress combination to cool their flowers and limit heat‐induced negative impacts on yield.