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Dr Graeme Mitchison

Dr Graeme Mitchison

We are deeply saddened by Graeme's recent death. He was a respected distinguished associate of SLCU and his contribution to the Lab's work was greatly valued.

Research Interests

I became fascinated by plant development in the late 1970's, when trying to understand phyllotaxis. This led to a meeting  with a remarkable botanist named Tsvi Sachs, who was developing his ideas about vein formation and canalization of auxin flow. I tried to cast his ideas in the form of mathematical models, and to understand what kinds of cellular mechanisms would be needed to make them work. I also tried to gain some insight into the way auxin moves between and within cells, and to estimate some of the rate constants. Then I moved continents and changed fields.

I can recommend returning to a field after twenty-five years. Science often moves slowly, but there is generally a cumulative achievement, and in botany this has led to a remarkable transformation. Today we can see entities that were only surmised when I was previously involved with the subject. There is now a rich abundance of signalling molecules, transporters, regulatory networks and subcellular structures that promise to give us a much deeper understanding of plant development. I am presently trying to catch up on this quarter decade of discovery, and to gain some insights into the way auxin seemingly controls everything.

I include below some papers from my earlier engagement with botany, and two more recent ones. I also include a paper from my alternative life as a physicist. In it, Richard Jozsa and I investigate how much information you can get from a quantum computer without switching it on.

Key Publications

Mitchison G.J. 1977 Phyllotaxis and the Fibonacci series. Science, 196, 270-275.

Mitchison G.J. 1980 A model for vein formation in higher plants. Proc. Roy.  Soc. Lond. B 207, 79-109.

Mitchison G.J. 1980 The dynamics of auxin transport. Proc. Roy. Soc. Lond. B 209, 489-511.

Mitchison G.J. 1981 The polar transport of auxin and vein patterns in plants.  Phil. Trans. Roy. Soc. Lond. B 295, 461-471.

Mitchison G.J. 2015 The shape of an auxin pulse, and what it tells us about the transport mechanism. PLoS Comput Biol 11(10): e1004487.

Mitchison G.J. 2016 Conformal growth of Arabidopsis leaves. Journal of Theoretical Biology 408, 155–166.

Mitchison G.J. & Jozsa, R. 2001 Counterfactual computation. Proc. Roy. Soc. A 457, 1175-1193.


This is taken from my 1981 paper on Polar Transport of Auxin and Vein Patterns in Plants, and shows canalization occurring in a model where the concentration of hypothetical transport proteins (little pins) increases with auxin flux.


This is taken from Bayer et al. (Genes and Development, 23, 373, 2009, Fig 2B, with thanks to the authors for permission), and shows canalization occurring in the early stages of leaf development in tomato. The green fluorescence shows the aggregation of PIN proteins (auxin transport proteins) on one face of each cell, as indicated by the arrows. There is general qualitative agreement with the 1981 figure, though it now seems that the underlying mechanism is much more subtle and complex.