This is a live Arabidopsis inflorescence with young flower buds developing at the periphery. Cell walls have been stained with propidium iodide (grey). Fluorescent reporters were used to monitor the expression of the APETALA3 (AP3, green), SUPERMAN (SUP, red) and CLAVATA3 (CLV3, cyan) genes. AP3 is required for the development of stamens (the male organs), while SUP establishes the boundary between the male and female part of the flower. CLV3 is expressed in stem cells. I try to understand how flowers develop from a few cells at the tip of the stem, and the genes and hormones that control this process. To this end, I use confocal imaging of live flowers, which allows me to follow the changes in morphology as well as gene expression and hormone response in 3 dimensions in flower buds as they form.