well-known soluble form, and the dis-
covery that cells adapted to growth on
an inhibitor of cellulose synthesis
could survive with almost no cellulose
in their walls—the latter showing just
how adaptable plants can be when chal-
lenged. But the enzyme cellulose
synthase still remained elusive. And
here we can learn another lesson—
don’t be afraid to collaborate and delve
into new areas of science. In order to
get more comfortable working in mol-
ecular biology, I arranged a sabbatical
with Dave Stalker at Calgene, Inc. in
Davis California. Dave’s group was
interested in getting more good cotton
fiber-specific promoters and we were
interested to try to identify the gene for
cellulose synthase—so we combined
forces using our own cotton fiber
cDNA library—Dave got his promoters
and together we identified for the first
time two sequences that encoded pro-
teins that had all the domains expected
for a cellulose synthase (plus a few
more interesting domains!) and was
highly-expressed just at the time fibers
underwent a 100-fold increase in cellu-
lose synthesis as they initiated secondary
wall synthesis. Discovery of these genes
allowed theArabidopsisgurus to find
similar genes and show that when dis-
rupted they did indeed lead to loss of
ability to synthesize cellulose synthesis.
From there, the field now has beenjoined by a healthy number of young
new faces, and new discoveries about
the process seem to emerge every
month. We too found thatArabidopsis
had many advantages and used it to
advantage once I relocated my lab to
UC Davis. Yet the power of being able
to combine my old skills in biochemistry
with the new skills in molecular biology
I think has proved to be a very important
aspect of my work.Finally, my dad—who loved medicine
because it combined good science with
helping people—would be proud of
me at last. At age 60, I made the
unusual choice to retire from academia
and work for the Rockefeller
Foundation where I spent 5 years devel-
oping a portfolio of grants that built
capacity in biotechnology in the devel-
oping world—especially sub-Saharan
Africa—and supported projects that
aimed to demonstrate that biotechnol-
ogy can offer solutions to at least
some problems that breeders find
intractable. I’ve enjoyed this new chal-
lenge immensely—and now have
another new one—retirement! But I
continue to consult on issues of inter-
national agriculture and, in a twist,
have also found my knowledge of cellu-
lose synthesis again valuable to those
working on biofuels. So it’s been an
interesting life—and it’s not over yet!References
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