Natural variation of bioactive gibberellin levels in maize tissues across North America

Gibberellins (GA) are plant hormones that regulate growth and development throughout the plant life cycle. While gibberellins have been extensively studied under controlled conditions for their fundamental role in plant adaptation and agronomic trait development, field-based data on their natural variation of bioactive GA levels across diverse agricultural genotypes and environments remains limited. To address this knowledge gap, we analyzed bioactive gibberellin A1 (GA 1 ) and gibberellin A4 (GA 4 ) in multiple maize tissues from commercial conventional maize hybrids grown in diverse field environments using high-throughput liquid chromatography-tandem mass spectrometry (LC-MS/MS). This study provides quantitative measurements of GA 1 and GA 4 levels in maize tissues collected under standard agricultural practices and describes variation influenced by genetic background and environmental conditions. Our findings demonstrate that GA 1 and GA 4 concentrations from conventional maize samples varied across maize tissue types, hybrid, and field sites. Analysis of variance components indicated that the site variation was statistically significant in five of ten gibberellins by maize tissue combinations, while the genetic component was significant only for GA 4 in grain samples, suggesting that environment factors have a larger effect than genetic factors Positive correlations between GA 1 and GA 4 were observed consistently across maize tissues except root. These findings offer preliminary insights into the interplay between genetics and environment, across germplasm and environments that have been previously described.