Pioneering Research On Ion Transport In Plants.pdf

Enid MacRobbie was born in Edinburgh, Scotland in 1931 and studied physics for her B.Sc. degree, earning a 1st class honors in 1953. She stayed at the University of Edinburgh for her Ph.D., becoming the first graduate student in Jack Dainty's new biophysics research group. Her Ph.D. project made the first use of radioisotopes to measure ion fluxes in plants, initially with seaweeds Rhodymenia palmata and Ulva lactuca, and later with the giant internode cells of the alga Nitellopsis obtusa.

Her thesis work established the theoretical framework for and practical application of isotope efflux analysis, a technique developed in animal cells but complicated in plants due to the presence of the large central vacuole. The resulting papers were pioneering and immediately established Enid's reputation in her chosen field. After completing her Ph.D. in 1957, Enid moved to a postdoctoral position with Professor H. H. Ussing at the Institute of Biological Isotope Research in Copenhagen, where she studied ion transport in frog skin.

Enid then secured a Research Fellowship at Girton College in Cambridge and moved back to the United Kingdom. Her initial hope was to work with Nobel Laureate Alan Hodgkin in the Department of Physiology, but given her interests, he suggested that it might be better if she joined George Briggs, Professor of Botany, who was interested in the ionic relations of plant cells. This began her association with the Botany School (now Department of Plant Sciences) in the University of Cambridge, where she has been an inspirational colleague for over 40 years.

Briggs gave Enid freedom to follow her instincts, and she began using isotopes to measure fluxes of K+, Na+, and Cl- in the giant alga Nitella translucens. Her main aim was to establish which fluxes at the plasma membrane and tonoplast were active and which were passive, and how they were regulated, information essential to establish the molecular mechanisms of ion movement in plants. The work was outstandingly successful, securing her international reputation and helping establish a more quantitative and biophysical approach to studies of plant transport systems.

In 1962, Enid was recruited to the Demonstratorship at Cambridge, a non-tenured Assistant Professorship, after Michael Pitman left for the University of Adelaide. Her research was given a major boost when, in 1964, she, Jack Dainty, and Charles Whittingham were awarded a substantial 5-year grant by the Nuffield Foundation, allowing Enid to build a group quickly and establish strong links with the Dainty group in Norwich.

The Nuffield grant came with no strings attached, and Enid could spend with complete flexibility, a sharp contrast with the limitations placed on modern grants in these days of accountability. This period also saw the start of Enid's role as an inspirational Ph.D. supervisor when F. Andrew Smith joined her in 1962 as her first Ph.D. student. A year later, John Raven and John Cram were recruited, and the group quickly grew to ten, including Roger Spanswick, who was a postdoctoral associate.

From 1962 to the mid-1970s, the group was concerned mainly with characterizing ion fluxes at the plasma membrane and tonoplast of giant algae, but in 1978, Enid made a major change in research direction when she decided to begin studying the mechanism of stomatal guard cell movement, the fundamental process by which plants regulate the uptake of gases and the loss of water.

Enid's laboratory has been the incubator for the fledgling career of many now-distinguished plant physiologists, including F. Andrew Smith, John Raven, John Cram, Roger Spanswick, Mel Tyree, Richard Williamson, Dale Sanders, Roger Leigh, Carol Shennan, Mike Blatt, Mark Tester, Mary Beilby, and Gerhardt Thiel. Enid's input to the work of her colleagues is always constructive, and she is able to identify and focus on the key issues, drawing the best out of others. Her positive outlook on the work of her colleagues remains the abiding memory of many of her former students and postdocs.

An unusual feature of Enid's approach is that she has actively encouraged the majority of the people who have worked with her to publish papers without her name on them, thus only about 25% of the papers published by her colleagues during their time in her lab have included her as a co-author. This has been a remarkably selfless approach to science that has given added impetus to the careers of those whom she has mentored.