Malcolm Barrett Wilkins (1933–2025), renowned plant physiologist and former Regius Professor of Botany at Glasgow, died in September 2025.
Dr Jennifer Deegan, a volunteer researcher at the Department of Plant Sciences, shares a tribute in celebration of his life and the scientific achievements he made. Dr Deegan specialises in the photography of gametophyte ferns and received her training in this work in Malcolm Wilkins’ lab when she was an undergraduate in the 1990s.
Professor Wilkins was a valued friend and collaborator with many here in the Department of Plant Sciences in Cambridge and will be fondly remembered and sadly missed.
Professor Malcolm Barrett Wilkins (1933–2025)
Plant physiologist who revealed how plants sense light and gravity
For generations of students and researchers, Malcolm Wilkins helped reveal the hidden lives of plants — how they grow, respond to light and mark the passing of time. Wilkins, who has died aged 92, combined meticulous experimental science with a rare gift for explanation and visual communication.
Born in Cardiff in 1933, Wilkins studied and began his academic career at King’s College London, with Fellowships at Yale and Harvard Universities. These were followed by Professorships at the Universities of East Anglia, and Nottingham, and then the Regius Professorship of Botany at Glasgow (1970 – 2000).
Wilkins’ greatest scientific achievement was to demonstrate the active transport of auxin, which is key to understanding how plant shoots orient toward light. This is now a staple part of school biology teaching. Active transport of the hormone to the shaded side of a shoot causes the shoot to lengthen on that side, so the shoot curves towards the sun. Meticulously produced photographs of tiny agar blocks on the tips of oat seedlings left students in no doubt about the meaning of his discovery.
Later, Wilkins collaborated with NASA and the European Space Agency to send plants into space to study the effect of gravity on roots. This produced some fine photographs which told the story so clearly to his students.
Further research focussed on circadian cycles in CAM metabolism in Bryophyllum plants (these plants only breathe at night). Wilkins demonstrated how the plants can have their internal body clocks changed by the intensity of light. In layperson’s (slightly humorous) terms, he showed us how plants can experience jetlag. This work developed into a long and fruitful collaboration with many colleagues, lasting more than 30 years (publications: 1959 – 1992).
This work was all part of Wilkins’ mission to show us the physiology of plants, or in his words, “how plants remember, tell time, form relationships, and more”.
Students knew him as an engaging storyteller. One favourite involved him drawing the stigma of an Amaryllis flower over 60 feet along the wall of the lecture theatre, to show the immense distance that a pollen tube must grow to reach an egg.
In another he shot a plant with a starter pistol to demonstrate ballistic DNA transformation (before the gun laws changed). This lecture was something of a legend among students, and is always the first thing mentioned during reunions, even thirty years later.
Students were also entertained and encouraged by many real-life anecdotes from his own youth. These included a day when his own undergraduate friends painted a zebra crossing across the Strand, receiving only a ticking off from a police officer. In teaching about light, he also told us of his undergraduate trips to a ballet theatre, where the arc lamps on stage rained down soot from their carbon rods when lit. Going back further, Wilkins own childhood was spent in Cardiff during heavy bombing of World War 2. He told us of his primary school days, when they worked in overcoats and did regular star jumps to keep warm in days where there was no heating. With kindness and humour, he was always able to encourage us along.
A first-rate plant photographer, some of his photographs took immense care to prepare. A sweetcorn kernel cut in half, with the carbohydrate store dyed black with iodine to distinguish it from the embryo, took hundreds of attempts. A photo of a gametophyte and sporophyte fern together had to be photographed in a fish tank for humidity. Portrait photos of individual plants were always carefully lit with three lamps to give the maximum sense of depth. These skills were meticulously passed on to students who wished to learn.
Wilkins’ book: ‘Plant Watching: How Plants Remember, Tell Time, Form Partnerships and More’, stands out for the crystal clarity of explanations. He describes the process of photosynthesis, from start to finish, one electron jump at a time. This is notable, as his own university lecturers would have known photosynthesis only as an empty black box in a textbook, with carbon dioxide going in at one side and oxygen coming out on the other. His talent for explaining complex topics simply was a real gift to his students.
Beyond his university work, he chaired the Board of Trustees of the Royal Botanic Garden Edinburgh, was Chairman of the Life Science Advisory Committee of the European Space Agency in Paris and was an honorary correspondent of the American Society of Plant Physiologists. He was a Fellow of the Royal Society of Edinburgh and served as its Vice President from 1994 to 1997.
Though he had an impressive list of personal achievements, the overriding impression he left on his students was his delight in their own work. He was always ready to listen when young students told him in detail of their own adventurous scientific plans.
Although he had so many great achievements, Malcolm B. Wilkins will be missed most as an inspirational teacher, for whom kindness, humour and gentlemanly behaviour were fundamental — as he always said, “A polite letter costs nothing”.
He is survived by his wife, Patricia, and his son, Nigel. His daughter, Fiona, who died young, was remembered with great fondness throughout his life, including in stories he shared with his students.
Text by Dr Jennifer Deegan, Visiting Scholar at the Department of Plant Sciences.
References:
- Wilkins M. B., Martin M.: ‘Dependence of Basipetal Polar Transport of Auxin upon Aerobic Metabolism.’ Plant Physiology, June 1967. DOI: 10.1104/pp.42.6.831.
- Wilkins M. B.: ‘An endogenous rhythm in the rate of carbon dioxide output of Bryophyllum. IV. Effect of intensity of illumination on entrainment of the rhythm by cycles of light & darkness.’ Plant Physiology, November 1962. DOI: doi: 10.1104/pp.37.6.735.
Image: (left to right) a bisected sweetcorn seed from Malcolm B. Wilkins’ research – the endosperm dyed black with iodine; portrait of Malcolm B. Wilkins as a young adult; Malcolm B. Wilkins in Glasgow robes on graduation day for students.