Jake MacMillan: A pioneering chemist in plant biology.

Jake MacMillan, who died on May 12, 2014 at the age of 89, was an organic chemist who made an enormous contribution to plant science, particularly in relation to the structure, biosynthesis, and analysis of the gibberellin plant hormones. Jake was born in Wishaw, Scotland, into a lower working class environment in which there was very little spare cash. Despite offers of a safe, steady job in a bank or an opportunity to become a professional soccer player, which—as sources of financial security—must have been very tempting, Jake was determined to pursue a career in chemistry and was the first in his family to attend university, obtaining his Bachelors of Science and Doctorate from the University of Glasgow. During his university years, Jake played soccer semiprofessionally, obtaining much-needed income to support his studies. Jake reminisced entertainingly about his education and career in an autobiographical article published in the Annual Review of Plant Physiology and Plant Molecular Biology (1). After receiving his doctorate in 1948, Jake took a job in industry, joining a group of chemists at the Imperial Chemical Industries (ICI) Akers Research Laboratories near Welwyn, England to work on the isolation and structural determination of fungal metabolites as potential pharmaceuticals. Jake was involved in the discovery of a number of novel bioactive natural products; the most well-known was griseofulvin, an antifungal compound, still in medical use today (2). Jake maintained his interest in fungal metabolites throughout his career and they provided topics for many a doctorate student. It was at the Akers Laboratories that Jake first became involved with the gibberellins. These metabolites of the fungus Gibberella fujikuroi were discovered in Japan and came to the attention of the West in the late 1940s through entries in Chemical Abstracts. The profound effect of these metabolites on plant growth and development was of immediate interest to agriculturalists and motivated the ICI to investigate them further. The team’s experience with submerged fungal cultures enabled them to isolate large quantities of the major metabolite, gibberellic acid (GA3), and to determine its structure (3). The ability of GA3 to restore growth to dwarf mutants suggested that these compounds may function as endogenous growth regulators in plants, and indeed extracts from several plant sources were found to have similar biological activity. Jake and colleagues were inspired to provide chemical support for this hypothesis and extractedmilligram quantities of a gibberellin from 100 kg of immature seeds of runner bean, showing it to be identical to a minor G. fujikuroimetabolite, GA1 (4). Thus, a new field was born and Jake was destined to play a major role in it. After the closure of the Akers Laboratories in the 1960s, Jake decided to leave the ICI and join academia, taking up a position as lecturer in the School of Chemistry at Bristol University. A colleague of his at Bristol, Bob Binks, was setting up the fledgling technique of gas chromatography and Jake saw its potential for the gibberellins, particularly when combined with the analytical power of mass spectrometry. The development of combined gas chromatography-mass spectrometry (GC-MS) for the analysis of gibberellins and another plant hormone, abscisic acid, in plant extracts by Jake’s group provided the first examples of the use of this technique in plant science (5, 6). By this time, the number of different gibberellins that had been characterized from G. fujikuroi and plant sources, many in Jake’s laboratory, had grown substantially, with their nomenclature becoming haphazard and confusing. This haphazard nomenclature prompted Jake and the Japanese chemist Nobutaka Takahashi, who became a close friend of Jake’s, to propose extending the numbering system that had been used for the fungal gibberellins, and this has proved to be a highly successful system (7).