Photosystem II Subunit S overexpression increases the efficiency of water use in a field-grown crop.

Insufficient water availability for crop production is a mounting barrier to achieving the 70% increase in food production that will be needed by 2050. One solution is to develop crops that require less water per unit mass of production. Water vapor transpires from leaves through stomata, which also facilitate the influx of CO during photosynthetic assimilation.