RT Journal Article
SR Electronic
T1 High-throughput profiling identifies resource use efficient and abiotic stress tolerant sorghum varieties
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 132787
DO 10.1101/132787
A1 Kira M. Veley
A1 Jeffrey C. Berry
A1 Sarah J. Fentress
A1 Daniel P. Schachtman
A1 Ivan Baxter
A1 Rebecca Bart
YR 2017
UL http://biorxiv.org/content/early/2017/05/01/132787.abstract
AB Energy sorghum (Sorghum bicolor (L.) Moench) is a rapidly growing, high-biomass, annual crop prized for abiotic stress tolerance. Measuring genotype-by-environment (G x E) interactions remains a progress bottleneck. High throughput phenotyping within controlled environments has been proposed as a potential solution. Early, measureable indicators of desirable traits that translate to the field would increase the speed of crop improvement efforts. Here we identify shape, color and ionomic indicators of abiotic stress for genetically diverse sorghum varieties. We subjected a panel of 30 sorghum genotypes to either nitrogen deprivation or drought stress and measured responses within an automated phenotyping facility, followed by ionomic profiling. Images of growing plants were collected every day for three weeks, and key metrics are reported. Responses to stress were quantified using differences in shape (16 measureable outputs), color (hue and intensity) and ionome (18 elements). We found shape characteristics to be reliable indicators of performance under both stress conditions tested. In contrast, color was a defining indicator of nitrogen starvation but not drought stress. Through this analysis we were able to measure the speed at which specific genotypes respond to stress and identify individual genotypes that perform most favorably under these stress conditions. These data are made available through an open access, user-friendly, web-based interface. Ionomic profiling was conducted as an independent, low cost and high throughput option for characterizing G x E. The effect of genotype on the ionome was consistent between the two experiments confirming the robustness of the high throughput platform. In addition, multiple individual elements were identified as quantitative outputs of abiotic stress. While the important challenge of translation between controlled environment- and field-based experiments remains, the multiple revealed quantitative outputs from different abiotic stress conditions are genetically encoded. Consequently, the genetic explanations for these responses can now be elucidated using classical and molecular genetics. We propose this work as a time efficient method of dissecting the genetic mechanisms used by sorghum to respond to abiotic stress. In summary, this work provides a mechanism to overlay high throughput phenotyping with field studies to accelerate crop improvement.AUTHOR SUMMARY Sorghum is important for food security in developing countries and has potential as a high yielding biofuel crop. In either setting, the plant is likely to experience resource limited growing conditions. ‘Resource use efficiency’ and ‘abiotic stress tolerance’ are distinct biologically important phenotypes. The former refers to the ability of a crop to translate a provided resource, such as fertilizer or water, into yield. The latter refers to the ability of a crop to survive within resource limited environments. Here we describe and apply high-throughput phenotyping methods and element profiling to sorghum under abiotic stress conditions. We quantify abiotic stress responses of genetically diverse sorghum accessions based on color fluctuations, biomass accumulation, growth rate over time and elemental profile. Through this analysis we report ‘resource use efficient’ and ‘abiotic stress tolerant’ sorghum.