Cereal blueprints for a water-limited world

Abstract

Crops with enhanced adaptation to a hotter and drier world are needed to combat climate change. Plants are sessile organisms and are therefore unable to seek out environmental conditions optimal for their growth and development. Instead, they must complete their life cycles in the environment in which they are growing. However, plants are remarkably plastic, such that a single genotype can exhibit multiple phenotypes, depending on the environment and management scenarios in which they are grown. Developmental plasticity can significantly improve yield stability in agriculture. In our ARC Discovery project (Cereal blueprints for a water-limited world), we are assessing the role of two gene families (PIN and VRN) in two model cereal crops (sorghum and barley) to better understand how these genes might regulate above- and below-ground plant architecture, thereby potentially enhancing resistance to abiotic (drought, nutrients) stresses. Overexpression and knockout lines were developed for both gene families in both cereal crops. We show that PIN genes modify canopy, root and panicle architecture in sorghum and root architecture in barley. Furthermore, we demonstrate that VRN genes modify leaf length in barley and stem width and panicle length in sorghum. These findings show that manipulation of PIN and VRN genes can lead to phenotypes with altered canopy and root architectures, with the potential to create genotypes that are better adapted to future climates.