• Tissue structures within the leaf of an Arabidopsis thaliana seedling

    Date:18 September 2012 Tags:,

    Fernan Federici and Jim Haseloff

    This confocal micrograph shows the tissue structures within the leaf of an Arabidopsis thaliana seedling. The sample was fixed and stained with propidium iodide, which labels DNA, but was imaged four years later. Over time, oxidation of the stain in different parts of the tissue provides differential fluorescent properties that can be excited with distinct wavelengths of light from a confocal microscope. The researchers are using these techniques to investigate cellular architecture in plants and gene activity.

    Why is Arabidopsis used as a model organism?
    Arabidopsis thaliana is used across different laboratories for plant research. The plant has several advantageous features that make it suitable for genetic and molecular biology research. A large proportion of its 125-megabase genome has been sequenced, and genetic maps of all five chromosomes are available. In addition, its short life cycle (approximately six weeks from germination to seed maturation) allows rapid experimentation. Importantly for laboratory conditions, Arabidopsis is easily cultivated in limited space. This has led to a large collection of mutant lines, standard protocols for growth and transformations and well-described cellular organisation of tissues.

    Why did the judges choose this image?
    Alice Roberts (anatomist, author and TV presenter) explains: “I love this slightly ethereal image. It has an other-worldly, magical quality to it. But what we’re looking at are the cells of the diminutive brassica, Arabidopsis, much loved by plant geneticists.”

    The 12th Wellcome Image Awards were announced on 20 June 2012, recognising the creators of the most informative, striking and technically excellent images among recent acquisitions to Wellcome Images, as chosen by a panel of judges.