EAGER: Predicting Drought Adaptation in C4 Plants with High Throughout Quantitative Phenotyping

Purdue University, West Lafayette IN

Investigators

Abstract

This EAGER project will test whether use of a novel combination of high-throughput field-scale measurement of ion accumulation levels and carbon isotope discrimination can predict yield under stress in maize. If successful, this project will generate a new paradigm for the study of abiotic stress tolerance in maize and other C4 plants and the immediate improvement of crop abiotic stress tolerance by the plant breeding industry. It could also enable scientists to rapidly predict the consequence of genotype on adaptation to increasing temperature, decreasing water arability, and other predicted outcomes of global climate change. A postdoctoral scientist will receive training and mentorship in the integration of high throughput phenotyping, bioinformatics and quantitative genetics. All data generated in this study will be accessible through iHUB (www.ionomicshub.org) and the Purdue University Research Repository (http://purr.purdue.edu). Many phenotypes used for drought tolerance estimation in plants are slow, costly, and of insufficient heritability to make substantial progress connecting genotype to phenotype. Measures of water relations often assess dynamic responses of the plant to the local environment, are strongly influenced by temporal factors and unusable for genetics. The absence of high throughput quantitative phenotyping approaches (e.g. phenomics) that precisely report the integrative physiological status of field-grown plants is hampering the discovery of molecular mechanisms of plant adaptation. This problem is particularly notable in plants with C4 photosynthesis and has limited the discovery of the mechanisms controlling water use in these drought adaptable species and inhibited crop improvement in maize and in many target biofuel crops including sorghum and switchgrass. Preliminary data suggests a correlation between delta-13C, the ratio of stable isotopes 13C:12C, and yield under drought and the relationship between delta-13C, water relations, and photosynthetic capacity in C4 plants. This EAGER project will test the hypothesis that the combination of water-soluble element accumulation and carbon isotope ratios in mature maize kernels can predict adaptation to drought. The specific objectives include a genome-wide assessment of genetic contribution to these traits by genome-wide association study. Both traits will be assessed within an association panel of maize in the field under a managed drought environment.