Thursday, October 22, 2015
Nature’s Palette: Elucidation and Engineering of the Plant Betalain Pathway
Department of Plant & Environmental Sciences, Faculty of Biochemistry, Weizmann Institute of Science, Israel
Betalains are tyrosine derived red-violet and yellow pigments that paint all the cacti and many other plant species as well as some higher fungi. Because of their relative paucity in nature, betalains have been the subject of only limited research, and as of today, little is known with respect to their biosynthesis, regulation and function in plants. Nevertheless, betalains hold both scientific interest and economic significance. Their pH in-dependence and relatively high stability compared to other natural pigments as well as their antioxidative properties make them a natural pigment of choice for food and dietary supplements industries. Within the plant kingdom, betalains are found in only one group of angiosperms, the Caryophyllales. In this order, betalains and anthocyanins occur in a mutually exclusive fashion, i.e. no plant species produces both types of pigments. This phenomenon raises interesting questions regarding the evolutionary history of these two classes of pigments. The molecular basis behind the mutual exclusion of betalains and anthocyanins is not entirely understood. Our research focuses on elucidation of the biosynthetic pathway of betalains. Transcriptome analyses of several betalain-producing plant species led us to discovery of new betalain-related genes and gene functions, and have enabled us to engineer heterologous betalain production in plants and microbes. Additionally, a focused study on the betalain-producing plant species Mirabilis jalapa (four O’Clocks) resulted in new insights regarding the evolutionary interplay between betalain and anthocyanin pigments.
Contact : Simon Michaeli