This month's winning image was submitted by Sergio Svistoonoff (Institut de recherche pour le développement, Montpellier, France (Sergio.Svistoonoff@mpl.ird.fr)). It shows shoots from Allocasuarina verticillata that are expressing green fluorescent protein (GFP) under the control of the 35S promoter.

GFP is expressed in the phloem cells. The chloroplasts of the mesophyll cells fluoresce in red, whereas the lignified cells of the epidermis and the xylem vessels appear in light blue. The image was acquired from transversal shoot sections under blue-UV light using a Leica-DMR microscope, with an epifluorescence filter A (Leica). Bar, 100 μm.

We are pleased to acknowledge the help of our two external advisors, Ariel Ruiz i Altaba (Developmental Genetics Program, New York Medical Center) and Lelio Orci (Department of Morphology, University Medical Center, Geneva).

To see more Cell of the Month winners, please visit our Cell of the Month archive: Cell of the Month archive