Transcription regulation of resilience to photo-inhibition under chilling conditions in maize

Global food demand is expected to increase substantially over the coming decades, with a predicted increase in human population from 7.5 billion currently to 10 billion by 2050 and significant shifts to increasingly calorie-rich diets. This comes at a time when productivity increases of several major food crops through conventional breeding have slowed down and global climate change is putting additional pressures on food production, especially via extreme weather events. Investing in sustainable and resilient crop productivity per unit land area is urgently needed, if humanity is to successfully avert future global food crises.

Maize, a C4 crop domesticated in Mexico 9,000 years ago, is highly sensitive to chilling temperatures, especially when combined with light exposure, leading to chilling-induced photoinhibition. This limits maize yields in temperate regions, where short growing seasons and cold snaps reduce early leaf development and overall crop productivity. The central aim of this project is to improve the understanding of genetic differences in sensitivity to chilling-induced photoinhibition to aid the development of superior maize germplasm for temperate regions.

This project will use a novel maize population with structured genetic variation to identify differences in traits involved in chilling-induced photoinhibition that are statistically correlated to genetic variation. Similarly, variation in gene expression levels will be measured and correlated to sequence variation at specific genomic locations. Using these parallel experimental approaches under field and controlled environment conditions, the project will identify specific genes that are central in controlling gene expression in response to chilling and high light, as well as pinpoint which genomic locations in maize show variation that correlates with the expression of these control genes. The project’s outcomes will increase the availability of genetic markers for the breeding of chilling-tolerant traits, as well as enhance understanding of the role of gene expression responses in improving chilling tolerance in maize.