Lighting up plant cells to engineer biology

A new technique using fluorescence to automatically measure and map cellular activity in living plant tissue will contribute to better computer models that are at the heart of synthetic biology, the attempts to engineer living systems.

The team at the University of Cambridge’s Department of Plant Sciences, led by Dr Jim Haseloff, have been working to uncover the mysteries of biological systems in certain plants - characterised by the highly complex genetic and cellular networks which are locked in a vast network of interactions - resulting in self-repair and reproduction in the organism.

These evolved biological systems are capable of creating structures of a hugely complex nature, far more sophisticated than the most advanced man-made materials - which the plants do in a renewable and, if it could be harnessed, a potentially very cheap way.

By creating new techniques allowing ever more detailed study of the cellular activity of plants, scientists believe it may be possible to reprogram living systems - which has given rise to an emerging field known as Synthetic Biology, which applies engineering principles to the building blocks of organic life.

“Synthetic Biology is based on the use of reusable components and numerical models - for the design of biological circuits, in a way that has become routine in other fields of engineering,” says Haseloff.

“Techniques such as the one we have developed will help us to discover more about the thrilling complexities of life at this level, and how we might be able to utilise the power of plants and their cellular networks in engineering - potentially revolutionising the way we engage with organic matter.”

At the moment, Synthetic Biology is in its infancy, and there is a critical need for improved techniques for measuring biological parameters within still living systems of cells.

This new technique - outlined in a paper published on the Nature journal’s Methods website on Sunday - involves fluorescent proteins, such as those originally found in certain jellyfish and corals. The proteins are used to mark and consequently identify specific parts of cells - the nuclei and membrane - mapping the development, position and geometry of the cellular make-up in the living plant tissue.

The researchers combine the advanced imaging processes with algorithms that automate quantitative analysis of cell growth and genetic activity within living organisms to precisely reconstruct cellular dynamics - and produce a numerical description that can be used to inform computer models.

In this way the cellular properties in intact plant tissue can be observed in depth – and be converted to mathematical descriptions of the living processes. This opens the door for the construction of new computer models for Synthetic Biology and the engineering of living tissue.

Adds Haseloff: “We have been able to use the very latest technical advances in microscopy for quantitative analysis of cell size, shape and gene activity from images of living plant tissues. This new technique, which we call in planta cytometry, will contribute to a greater understanding of plant development, physiology and help pave the way for advances in biological engineering.”