Shang Fa Yang: Pioneer in plant ethylene biochemistry

Shang Fa Yang was born in Taiwan in 1932. After receiving his B.S. and M.S. degrees in Agricultural Chemistry from the National Taiwan University, he came to the United States in 1958 to pursue a Ph.D. degree at Utah State University. Following three postdoctoral years, he was hired at the University of California, Davis, in 1966 where he was a biochemist and professor for 28 years. After retiring early from UC Davis, he subsequently established a research program at the Hong Kong University of Science and Technology and served as Vice President of Academia Sinica in Taiwan. Yang’s research achievements included discovering the biochemical pathway for the synthesis of ethylene by identifying the key steps by which S-adenosylmethionine (SAM) is converted into 1-aminocyclopropane-1-carboxylic acid (ACC) and subsequently into ethylene. Yang further demonstrated how the methylthio and ribose moieties from SAM were recycled back into methionine in order to sustain high rates of ethylene synthesis, as in ripening fruits. This recycling pathway is now known as the Yang Cycle. Yang also contributed to the isolation, characterization and cloning of ACC synthase and ACC oxidase, the two enzymes in the ethylene biosynthetic pathway, and to the elucidation of their structure and reaction mechanisms. He made important contributions to auxin, cytokinin, cyanide and sulfur metabolism in plants as well. His work formed the basis for subsequent research that has established ethylene as the most thoroughly characterized of the hormonal biosynthesis and signaling pathways in plants. # 2008 Elsevier Ireland Ltd. All rights reserved.