Figure 1.

Oligonucleotides are taken up by intact plant tissues and are distributed throughout the cell. Confocal microscope image of cells from intact barley leaves following application of an 18-nucleotide oligodeoxynucleotide via the transpiration stream [5]. The oligonucleotide is labelled with the fluorescent dye Alexa Fluor 488 (Molecular Probes), and appears green in the image, whilst chloroplast autofluorescence appears red. Image provided by Professor Christer Jansson, Chuanxin Sun, Anna-Stina Höglund, Helena Olsson and Elke Mangelsen, The Swedish University of Agricultural Sciences.