Robert Henry Symons 1934-2006

Obituary

An Agricultural Science graduate from Melbourne University with a PhD in Biochemistry, Bob Symons was appointed lecturer in the Department of Agricultural Biochemistry at the Waite Agricultural Research Institute in 1962.

He transferred to the North Terrace Campus of the University of Adelaide in 1963. In the following 25 years Bob played a major role in the development of the Biochemistry Department, rising through the ranks to a Personal Chair in 1987.

He was a devoted and very able experimentalist who was usually to be found at his laboratory bench working with his research group. This gave his students first-class training and created an excellent relationship between them.

For the major part of his career he focused on the molecular biology of nucleotides and nucleic acids. On study leave in Stanford he and others were the first to join two stretches of DNA molecules together to form a single piece. This is an essential manipulative step in the later development of cloning techniques.

He also devised synthetic methods for making radioactive nucleotides. These are used for much of the experimental work in DNA technology. They are expensive and had to be imported into Australia. Bob for a long period made the necessary labelled nucleotides for the whole department. This was very important for the development of gene technology. It also became the basis for the establishment in 1982 of the first biotechnology company in Australia (Biochemical Research Enterprises of South Australia, later Bresagen) for making and supplying research materials. Bob was the prime mover in this company and later became its chairman.

It was Bob's interest in the molecular biology of plant viroid diseases in which he made his greatest mark. Viroids are the smallest pathogens known - the one that kills coconut palms is an RNA molecule only 246 nucleotides long, devoid of any protein or other component. It is far smaller than a virus. Bob's group determined the complete structure of the palm viroid (cadang-cadang). It was a major achievement; his work was published in Nature, and featured on its cover.

Bob also did extensive work on the replication of viroids in infected cells. Their RNA genomes are synthesised not one at a time but as a continuous molecule consisting of individual genomes strung together. They have to be separated into individual sections, a remarkably precise chemical process. Bob's group found that this separation occurred spontaneously by the self-cleaving process known as ribozyme action, which had been discovered previously by two Americans who were awarded the Nobel Prize for the discovery. Bob's work was a very important reinforcement of this. He and his students then investigated how the viroid RNA self cleaved. They elucidated the precise nucleotide structure that did the job at the cleavage site. The crucial piece of RNA folded up to resemble the head of a hammer. Bob published it as a "hammerhead" ribozyme, which is now a widely accepted term. Other laboratories have taken up this area and hammerhead biochemistry is almost a field of its own. Bob was recognised internationally as a leader in viroid molecular biology and nucleotide biochemistry in general. He was elected to the Australian Academy of Science in 1983 and the Royal Society of London in 1988.

Bob decided in 1990 that he should take his research group to the Waite Campus. Within the Department of Plant Science he established a new laboratory with Australian Research Council funding where his interests in the replication of plant viruses, identification of the functions of virus genes, intracellular localisation of viroids, and diagnosis of grapevine viruses and even phytoplasmas, occupied him for another 12 years.

His commitment to providing practical outcomes for viticulturists led him to establish the diagnostic company, Waite Diagnostics. The enviably low virus load of new Australian vineyards is partially due to his introduction of laboratory-based molecular methods for avoiding the use of infected planting material.

Bob is survived by his wife, Verna, four children, Helen, Richard, Alison and Michael, and eight grandchildren.

Contributed by John Randles, George Rogers and Bill Elliott