Variation in morpho-physiological and metabolic responses to low nitrogen stress across the sorghum association panel

Abstract

Background Access to biologically available nitrogen is a key constraint on plant growth in both natural and agricultural settings. Variation in tolerance to nitrogen deficit stress and productivity in nitrogen limited conditions exists both within and between plant species. However, our understanding of changes in different phenotypes under long term low nitrogen stress and their impact on important agronomic traits, such as yield, is still limited. Results Here we quantified variation in the metabolic, physiological, and morphological responses of a sorghum association panel assembled to represent global genetic diversity to long term, nitrogen deficit stress and the relationship of these responses to grain yield under both conditions. Grain yield exhibits substantial genotype by environment interaction while many other morphological and physiological traits exhibited consistent responses to nitrogen stress across the population. Large scale nontargeted metabolic profiling for a subset of lines in both conditions identified a range of metabolic responses to long term nitrogen deficit stress. Several metabolites were associated with yield under high and low nitrogen conditions. Conclusion Our results highlight that grain yield in sorghum, unlike many morpho-physiological traits, exhibits substantial variability of genotype specific responses to long term low severity nitrogen deficit stress. Metabolic response to long term nitrogen stress shown higher proportion of variability explained by genotype specific responses than did morpho-pysiological traits and several metabolites were correlated with yield. This suggest, that it might be possible to build predictive models using metabolite abundance to estimate which sorghum genotypes will exhibit greater or lesser decreases in yield in response to nitrogen deficit, however further research needs to be done to evaluate such model.

Comparative GWAS identifies a role for Mendel’s green pea gene in the nonphotochemical quenching kinetics of sorghum, maize, and arabidopsis

“…We observed substantial variation in nine traits describing NPQ kinetics (Table 1) in a population of 339 sorghum genotypes grown under low-nitrogen (LN) conditions in 2020 (Figure 1, Supplemental Figure S1). While the LN treatment was sufficient to decrease sorghum grain yield by 48% relative to high-nitrogen (HN) controls, and other traits measured in the same field experiment, such as flag leaf width and length, also showed significant differences between treatments (Grzybowski et al . 2022), we did not observe consistent differences in NPQ kinetics between LN and HN conditions years (Supplemental Figure S2).…”

“…The 2020 field experiment was planted on June 8 th , and the 2021 field experiment was planted on May 25 th . The 2020 field experiment has also been previously described (Grzybowski et al . 2022).…”

Data driven discovery and quantification of hyperspectral leaf reflectance phenotypes across a maize diversity panel

“…The transferability of the autoencoder derived variables with plant traits was assessed using two sorghum leaf reflectance datasets and associated ground truth data (Grzybowski et al 2022; Wijewardane et al 2023). The pre-trained encoder described above was used to summarize variation from hyperspectral leaf reflectance collected from 321 sorghum plants grown under greenhouse conditions in 2018, 132 sorghum plants grown in the field in 2020 under sufficient nitrogen conditions, and 136 sorghum plants grown in the field under nitrogen deficient conditions in 2020.…”

“…A comparable set of hyperspectral reflectance and molecular leaf trait data was collected for a sorghum population grown in field conditions and under different nitrogen treatments as previously collected and described in Grzybowski et al . (2022).…”

Grain Utilization by the Gut Microbiome as a Human Health Phenotype to Identify Multiple Effect Loci in Genome-Wide Association Studies ofSorghum bicolor

“…The seed for the Sorghum Association Panel (SAP) 18 used in this study was generated in a field increase conducted in 2020 at the University of Nebraska-Lincoln’s Havelock farm (N° 40.861, W° 96.598). While this field experiment has been previously described in detail 20 , briefly 344 sorghum genotypes listed in table S2, were planted on June 08, 2020. Each plot consisted of a single 2.3-meter row of plants of a single genotype with 0.76 meter spacing between parallel and sequential rows.…”