Methyl-Salicylate Clearing and Imaging of Maize Meristems

The final morphology of a plant is determined by much earlier events that occur during development. Meristems are critical for the development of the aerial parts of plants, such as leaves and stems. The morphology of these meristems, which can vary significantly across genetic backgrounds, correlates with phenotypic traits in Zea mays (maize) that influence yield, such as leaf initiation rate and kernel row number. Traditional methods for morphological analysis of meristems, including histological sectioning and fine dissection, often require considerable technical expertise. To address these challenges, we present a detailed protocol employing methyl-salicylate for tissue clearing, combined with Differential Interference Contrast (DIC) microscopy to visualize maize shoot apical meristems. This method enables the intact visualization of vegetative meristems without the need for extensive dissection, thereby preserving the natural morphology of the meristem. Using this approach, the meristem is coarsely dissected, fixed, optionally stained, and cleared to enable visualization through leaf layers. By improving the accessibility and quality of meristem imaging, this protocol facilitates accurate quantification of meristem morphology, critical for genetic and developmental studies. Optimized primarily for maize, the outlined techniques can also be adapted for other plant species, providing a versatile tool in the field of plant developmental biology.