The β-cyanoalanine synthase pathway: beyond cyanide detoxification.
Production of cyanide through biological and environmental processes requires the detoxification of this metabolic poison. In the 1960s, discovery of the β-cyanoalanine synthase (β-CAS) pathway in cyanogenic plants provided the first insight on cyanide detoxification in nature. Fifty years of investigations firmly established the protective role of the β-CAS pathway in cyanogenic plants and its role in the removal of cyanide produced from ethylene synthesis in plants, but also revealed the importance of this pathway for plant growth and development and the integration of nitrogen and sulfur metabolism. This review describes the β-CAS pathway, its distribution across and within higher plants, and the diverse biological functions of the pathway in cyanide assimilation, plant growth and development, stress tolerance, regulation of cyanide and sulfide signalling, and nitrogen and sulfur metabolism. The collective roles of the β-CAS pathway highlight its potential evolutionary and ecological importance in plants.
Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA.
Marylou
M
Machingura
Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA.
Eitan
E
Salomon
Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA.
Joseph M
JM
Jez
Department of Plant Biology and Center for Ecology, Southern Illinois University, Carbondale, IL, 62901, USA. ebbs@siu.edu.
Stephen D
SD
Ebbs
D003486:Cyanides / Q000737:chemistry / Q000378:metabolism*; D008190:Lyases / Q000737:chemistry / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D010944:Plants / Q000378:metabolism*
D003486:Cyanides; D008190:Lyases; C019955:beta-cyanoalanine synthase
cyanide; cyanide detoxification; nitrilase; nitrile hydratase; β-cyanoalanine; β-cyanoalanine synthase