Maize Developmental Biology: Fundamental Discoveries Unlocking Innovation.

Maize (Zea mays) is a cornerstone of agriculture and global genetics research. Every year more than 200 million hectares of maize are grown worldwide for human and animal consumption, and biofuel and energy production. Maize has also been a key research model organism since the 1800s, and over 150 years of research has led to many fundamental discoveries in genetics and developmental biology. These findings include "jumping genes" (transposons) and the first homeobox gene in plants, KNOTTED1, whose discovery overturned the hypothesis that homeobox genes were unique to animals. Research in maize has not only deepened our fundamental understanding of the world around us but has also driven crop improvements. Maize yield and resilience are intimately linked with plant morphology. Developmental biology aims to understand how morphology arises through the coordinated action of gene expression, hormones, cell behaviors, and biophysics across space and time. This review delves into the foundations of developmental analyses, spanning three components: morphology, time, and space. We also discuss the challenges inherent to maize developmental research, such as the inaccessibility of meristems and developing organs, and introduce techniques that address these challenges.