Reprinted with permission from the Botanical
Electronic News (click here to see original article on BEN)
Neil Towers, a much respected scientist and Professor at
the University of British Columbia, passed away on November
15th, 2004 in Vancouver. He was 81. Predeceased by mother
Kathleen and brother Desmond, Neil will be lovingly remembered
and sadly missed by his wife Elizabeth and his eight children.
He will be greatly missed by colleagues, students, and friends
at the University of British Columbia (Botany Department)
and around the world.
UBC Emeritus Professor of Botany Neil Towers was well
known nationally and internationally for his outstanding
record of pioneering and sustained research in botany and
phytochemistry.
He was born in Bombay, India and grew up in Burma, where
his interest in the natural world began. He often spoke
of his childhood spent collecting poisonous snakes and other
curiosities in the forests near his home.
After time in the Royal Indian Navy Volunteer Reserve,
and a stint as a liaison officer in Bath, England, he was
awarded an Ajax scholarship to study in Canada. He obtained
his B.Sc. and M.Sc. from McGill University, and his Ph.D.
in 1954 from Cornell University. After academic appointments
at McGill and the NRC in Halifax, he was recruited to UBC,
where he served as Head of the Department of Botany from
1964-71, a period of great expansion of the Department.
After 1971, he devoted his full energies to his successful
career in research and teaching, which he continued as an
emeritus faculty member from 1989 until his death.
Neil was a Fellow of the Royal Society of Canada, from
whom he received the Flavelle Medal in 1986. He received
numerous research awards and prizes over his career. Most
recently, he was awarded the Pergamon Phytochemistry Prize
in 2000, and in 2001 was recognized by ISI as one of UBC's
(and the world's) most highly cited scientists. He published
more than 425 papers and book chapters, starting with a
1953 paper in Nature.
Neil was charming, funny and an excellent raconteur. Lab
parties at his Vancouver home often ended late at night,
with the room cleared to make space for dancing to his favorite
Django Reinhardt and latin music. He had an open door policy,
and always welcomed office visits by students or whoever
was interested in talking about plants and chemistry. He
traveled extensively to collect plants worldwide, mainly
in the tropics, and he returned from a trip to Peru only
this last summer. Many in the Botany Department at UBC will
remember the photos and artifacts from his travels that
decorated his office.
Neil loved what is now called biodiversity: the shapes
and colours of plants and insects, and the variations of
chemical structures found in nature. His fields of study
included medicinal phytochemistry, ethnopharmacology, photobiology,
chemical ecology relating to plants, fungi and insects,
and biotechnology of plant cell and tissue cultures. He
conducted important early studies on phenolic metabolism
in plants, and on the interaction of light with phytochemicals
to produce toxicity. His lab investigated the chemistry
and antibiotic activity of many plants native to British
Columbia, including those used in traditional medicine.
Neil was also a great teacher of young scientists in Canada
and elsewhere, and many of his graduate students and postdoctoral
workers went on to establish their own labs. Perhaps his
greatest contribution to science was through this role as
mentor. A student in his lab couldn't walk by his office
door without being called in to discuss a new paper or a
new idea. It is through his infectious enthusiasm for science
and the natural world that the spirit of Neil Towers lives
on.
WHAT ARE YOU GOING TO BE WHEN YOU GROW UP, DAD?
From: G.H. Neil Towers. 2001.
I grew up in Myanmar (formerly Burma) when it was a British
colony. My parents sent me to boarding schools around the
country run by Christian brothers who sadly lacked an interest
in the natural sciences, particularly natural history. Living
and traveling as a schoolboy in perhaps one of the most
beautiful tropical countries on this planet, I developed
a craze for natural history. I collected snakes, beetles,
butterflies, dissected animals for parasites and tried to
identify plants from books. It was a happy boyhood. On reflection
I think I was lucky not to have lived in our computer and
television age. I did not see a television program until
I was about twenty two! I spent all of my holiday time escaping
prayers and wandering through the enchanting countryside
exploring nature. I was spellbound by the travels, adventures
and ideas of Darwin, Wallace, Bates and many other famous
explorers. That is exactly what I wanted to be. World War
II intervened.
I came to Canada on a scholarship for ex-naval officers
at the end of the war. I had many adventures during the
war, quite a number of which would have been called unforced
errors of life were they to be compared to a game of tennis!
Having escaped from the Japanese and winding up in England
and then Canada, my life changed and I was suddenly plunged
into the cloisters of academia. My sunny days of adventure
were over - perhaps forever.
I was saddened to find that there were very few enthusiastic
natural historians in this new life in a university. My
fellow undergraduates in fact never seemed to have had time
to talk about the excitement of biology they were so busy
cramming for exams. I found out also that the world appeared
to have been already explored by my arrogant zoology instructors
and there was little new to discover other than to climb
very tall moun- tain peaks or dive deep under the sea. I
was an Honours Zoology student at McGill University in Montr,al
at the time and was advised by zoologists that the secrets
of the animal world really lay in the realm of statistics!
Even genetics was all statistics according to them.
Botanists, in contrast, were fascinated by apparent trivia:
they were excited by the shapes of leaves, the hairiness
of plant structures (for which there are many unpronounceable
names) the geometry of flowers and a phenomenon called 2N
versus N. However these botanists seemed to love what they
were doing and I was encouraged to join their ranks. They
actually worked with their microscopes in the evenings.
They suggested to me that the inner workings of plants e.g.
how sugars are manufactured from a gas in light was irrelevant
and for Heaven's sake don't spoil things by dragging chemistry
into the picture in order to understand how a plant lives.
Of course, electron microscopy, the role of nucleic acids,
the nature of enzymes etc. were not even dreamed of at that
time. Professor R. D. Gibbs, a feisty botanist at McGill,
kindled my interest in plant chemistry. He was con- sidered
a crank by other botanists as I found out later because
he was fascinated by the chemical relationships between
plants. In fact he was a chemotaxonomist at a time when
chemists did not know the meaning of the word taxonomy and
a botanist might have been embarrassed if accused of understanding
anything about chemistry.
Here was a botanist who actually knew some phytochemistry
and, Good Lord, this chap could actually draw chemical structures!
We became good friends and I obtained an M.Sc. under his
supervision. The research involved the chemotaxonomy of
plant lignins and was published in Nature. Perhaps I was
the first person at McGill to use the new technique of paper
chromatography. Certainly, the chemists and biochemists
at McGill seemed to be as yet unfamiliar with the use of
this technology. Later on during a sabbatical leave with
the enzymologist D.D. Davis at the University of East Anglia,
I used to drink beer every afternoon with Dick Synge, one
of the discoverers of paper chromatography, a Nobel Laureate,
a seasoned beer drinker, and a very dangerous cyclist (after
drinking of course). Curiously Gibbs suggested that paper
chromatography would never work and that I should use fractional
sublimation instead to separate my products of alkaline
nitrobenzene oxidation, namely p-hydroxybenzaldehyde, vanillin
and syringaldehyde. Clearly this was not good advice because
his total NRC budget for the year was about $115! Gibbs
was old fashioned by current standards. It was good for
me. It made me more of an independent scientist. When I
asked him if he would be kind enough to read a draft of
my thesis he was astounded. "I am here to examine you
Towers, not to help you. It is your thesis - not mine!"
Nowadays, of course, there are many rules in Canadian universities
to chaperone graduates in thesis writing so that in the
end I feel we sometimes produce the well- known camel instead
of the desired racehorse.
I went to Cornell for my Ph.D. studies with Professor
F. C. Steward, a distinguished English plant physiologist
who boasted that he had never taken a course in botany in
his life. Needless to say he thought that he was the founder
of botany. He had achieved fame for his work on ion accumulation
in plants. His students called him the Golden Bantam because
he was small, a fearless fighter, and rather arrogant. He
once told me that he regretted the fact that dueling was
no longer encouraged as a means of resolving departmental
quarrels among faculty. He meant it!
Steward had become interested in the use of paper chromatography
for separating and identifying the many unidentified non-protein
amino acids in plants. My Ph.D thesis was concerned with
designing new methods for the identification of alpha-keto
acids in plants. Quite boring actually. It was a wonderful
period of study, however, because Steward had attracted
extremely knowledgeable postdocs, such as John F. Thompson,
and clever graduate students to his lab. He was also a research
supervisor who was so busy chasing research dollars that
we had complete freedom in our own programs. I think that
this is still the case in many universities.
At Cornell I took Botany and Biochemistry and a course
on enzymes by J. B. Sumner. After many years of tedious
research Sumner had discovered that the fewer steps involved,
the better were his yields of the hydrolytic enzyme urease
which he was studying in Canavalia ensiformis (Jack bean).
In fact, he discovered one day that a 32% acetone extract
heated to about 60 deg. C, filtered overnight through Whatman
paper into a graduate cylinder, and placed in a refrigerator
yielded a precipitate which, when examined under a microscope,
was found to consist of "octahedral" crystals.
The crystals had tremendous urease activity. Repeated analyses
showed that it was a protein. This was in 1926. Sumner wrote
in his lab notebook about this momentous day: "That
night I slept but little". At that time of course the
true nature of enzymes was unknown and the leaders in the
field, among them the very famous German biochemists, Willstatter
and Waldschmidt-Leitz, refused to acknowledge that a 26-year-old
American had actually isolated an enzyme and proven that
it was nothing more than a protein. His discovery was treated
with some ridicule which unfortunately made him rather bitter.
Four years later when Northrup crystallized the proteolytic
enzymes pepsin and trypsin from animal sources at the Rockefeller
Institute and showed that they are also proteins, Sumner's
achievement was acknowledged - they shared a Nobel prize.
We had the privilege of repeating Sumner's work in our laboratory
course and even of recrystallizing urease. Of course, like
Sumner, we made the entry "That night I slept but little"
in our laboratory notebooks.
I was offered a job as Assistant professor in the Botany
Department at McGill and assigned to teach plant anatomy,
plant physiology, plant biochemistry and help run introductory
botany labs. I inherited an old physics lab which could
only be accessed through a men's urinal, a bit of an annoyance
to my women graduate students. After four years of working
in this "lab" we discovered an open pool of about
40 kg of mercury under the wooden floor. It must have been
"lost" by the physicists during their war research
years. Also contributing to the poor working conditions
were the feral cats that had taken up residence in the dark
corners of this medieval set of rooms, occasionally emerging
to produce a litter of young kittens on our chromatograms
which had to be stored on the floor. The lab was cold and
we often had to use gloves and overcoats to stay warm during
the winter months. At that time, university startup money
for research was unthinkable. Besides, there were tons of
microscopes and herbarium sheets lying around. What more
could a botanist want? Roy Waygood, the plant physiologist
at McGill was most encouraging, allowing me access to his
lab equipment and his knowledge of plant physiology and
biochemistry.
Among the many wonderful graduate students in my lab was
our illustrious PSNA [Phytochemical Society of North America]
stalwart Ragai Ibrahim. Seichi Yoshida of Tokyo Metropolitan
University also joined me as a postdoc. Later his student,
Minamikawa, joined my lab and much later on Minamikawa's
student, Etsuo Yamamoto, came to my lab as a postdoc. That's
three generations of great Japanese phytochemists! We spent
a lot of time making 2D chromatograms of plant extracts,
cutting out spots, eluting them, and so on. I remember my
eight year old son spending an afternoon in my lab. After
watching me for half an hour he asked "What are you
going to be when you grow up, Dad?" It seems that in
his eyes I have never really grown up.
I was delighted to learn about the Birch and Donovan hypothesis
in relation to flavonoids. Instead of being neatly derived
(on paper) from two hexoses and a triose according to Geissman
and Hinreiner, they now appeared to be derived from a hydroxycinnamate
and acetate! We resolved to test this with the dihydro-chalcone
glucoside, phloridzin. Alas! We were beaten by Neish's group
at the National Research Council (NRC) of Canada in Saskatoon
who proved this hypothesis with quercetin, and Grisebach's
group in Germany who proved the hypothesis with an anthocyanin.
It seems silly now but we were dreadfully disappointed not
to have been the first to have proven that Birch and Donovan
were right.
I spent a summer at the NRC laboratories in Ottawa with
D.C. Mortimer and Paul Gorham, learning radiotracer techniques
and carrying out 14C photosynthesis studies. The following
summer I spent with Stewart "Coumarin" Brown and
Arthur Neish at the NRC laboratory (then called the Prairie
Regional Laboratory) in Saskatoon studying coumarin biosynthesis.
When I returned to McGill at the end of the summer Ibrahim
and I prepared twodirectional chromatograms of the phenolic
acids from a range of plants. Sprayed with diazotized nitroaniline
or diatized sulfanilic acid they gave a range of beautiful
colors. We had a special room set up with these large chromatograms
adorning the walls for participants of the IXth Botanical
Congress which was held at McGill, the Universit, de Montr,al,
and Sir George Williams College (now Concordia University)
that year. These chromatograms were works of art and admired
by all who visited us.
After enjoying more than nine years at McGill I was invited
by Art Neish to head up the Plant Biochemistry section of
the NRC's Atlantic Regional Laboratory in Halifax, Nova
Scotia to which he had been appointed Director. Neish was
considered to be one of the outstanding phytochemists in
Canada and I was delighted to join his institute as I had
a great admiration for him as a scientist and also because
I was jointly appointed as an Associate Professor to Dalhousie
University in Halifax where Neish and I taught a course
in comparative biochemistry. My graduate students at McGill
accompanied me there and had the advantage of working in
the well-equipped NRC labs and alongside distinguished Canadian
scientists in chemistry (Gavin McInnis) and biochemistry
(Leo Vining). We published many papers especially on the
biosynthesis of interesting lichen compounds as well as
on comparative phenylpropanoid metabolism in lycopods and
fungi. We showed clearly that L-tyrosine is metabolized
quite differently from L-phenylalanine, especially in vascular
plants. Tyrosine is metabolized to acetate and its derivatives
when introduced into plant tissues and phenylalanine is
the gateway to phenylpropanoid metabolism. We also identified
a new cyanogen from Taxus and studied its biosynthesis showing
that both the nitrogen and carbon are derived from L-phenylalanine.
We discovered psilotin, a glucoside derived from ahydroxycinnamate
and one equivalent of acetate, in the primitive ferns Psilotum
and Tmesipteris.
I next moved to the University of British Columbia in
Vancouver as Head of Biology and Botany, an administrative
position which tore me away from thinking time and plunged
me into the petty life of administration in a then impoverished
Canadian university. After five years, a sabbatical leave
in England where I studied enzymes with D.D. Davies at the
University of East Anglia, convinced me to resign as Head
and settle down again to research and teaching. As most
biology students at our universities do not enjoy chemistry
my classes were small and were therefore a great pleasure
to teach. Many more graduate students and postdocs passed
through my research program and it would take many more
pages to describe our further achievements in phytochemistry.