Associate Professor University of Nebraska-Lincoln Lincoln, Nebraska
The productivity of maize has been significantly affected by global climate change. To address this issue, it is crucial to have a comprehensive understanding of the metabolic interactions among its different organs. In this study, we reconstructed the first-ever genome-scale metabolic model for maize, iZMA6517. We contextualized this model heat and cold stress-related transcriptomics data using a novel algorithm called EXTREAM (EXpression disTributed REAction flux Measurement). Moreover, by applying metabolic bottleneck analysis to these contextualized models, we identified fundamental differences between the plant’s response to these two stresses. While both stresses had bottlenecks in reducing power, heat stress had additional bottlenecks in
energy generation. To establish a connection between these findings, we conducted thermodynamic driving force analysis, which revealed the importance of the thermodynamics-reducing power-energy generation axis in shaping the plant’s responses to temperature stress. This thermodynamics-reducing power-energy generation axis can be taken advantage of to engineer a temperature-tolerant maize genotype for global food sustainability. As a proof of concept, we experimentally inoculated a beneficial mycorrhizal fungus, Rhizophagus irregularis, to maize roots and demonstrated its potential to mitigate the effects of temperature stress. In summary, this study provides a blue-print for the engineering of temperature stress-tolerant maize ideotypes, aiming to address the challenges posed by global climate change and ensure food security.