Crop biotechnology for improving drought tolerance : targets, approaches, and outcomes

Human population growth and climate change threaten our food and water security. The increasing frequency of extreme drought events will cause major crop yield losses. To mitigate this threat to global food security, we need to rapidly select and/or develop new ‘climate‐ready’ crop varieties that can withstand and flourish under water deficit, enabling the sustained and sustainable production of higher yields to support human life on Earth. In this article, we identify the current targets for crop plant improvement under drought, working from the ground up, with modifications in rooting, shoot, stomatal, and photosynthetic systems, and finally nutrient transport and sink strength. We argue that by using a holistic approach to crop development, prudently incorporating the natural variation available in crop wild relatives and cultivars with cutting‐edge tools, such as molecular breeding and transgenics, we may be able to produce high‐yielding crops under a range of conditions to meet our needs in a changing world.