Final Activity Report Summary - PLANT COLD TOLERANCE (A novel non-CBF-regulon involved in cold acclimation in Arabidopsis)
Glucosinolates are natural plant products with many biological functions, such as defence compounds and flavour compounds in human consumption. Glucosinolates are degraded by endogenous myrosinases, or by microbial organisms in the gut. Certain glucosinolates are degraded into potent cancer-preventive agents such as sulphoraphane, which is derived from the glucosinolate glucoraphanin. The cancer-preventive properties of sulphoraphane are well documented, and there is a great interest in improving the glucoraphanin content in vegetables. Glucoraphanin is derived from the amino acid methionine. Through a three-step reaction, methionine is converted first to Dihomo-methionine (DHM), then to a parent glucosinolate called 4-methylthiobutyl glucosinolate, and finally to glucoraphanin.
During this project, we have introduced the entire glucoraphanin biosynthetic pathway into the tobacco plant, Nicotiana benthamiana and in the process elucidated the pathway and identified several key genes. We have shown reconstitution of DHM biosynthesis and in the process discovered three new genes that play key roles in this pathway. We have coupled DHM biosynthesis to glucosinolate biosynthesis and have succeeded in modifying the parent glucosinolate produced to the cancer-preventive glucoraphanin. In addition, we have assigned function to several previously uncharacterised genes in this part of the pathway.
The ability to transfer an entire 13-gene biosynthetic pathway to a heterologous organism is unprecedented and opens up vast opportunities for producing natural products in other species. 4-MSB has been found in a limited number of species in only five families of the Brassicales order. Due to its potent cancer-preventive properties, there is a great interest in investigating if it was possibly to reconstitute this pathway in other species. However, other glucosinolates are potent cancer-preventive agents such as 7-MSH and 8-MSO. These glucosinolates could be produced using the current method with few modifications. The current method can be used to produce any desired glucosinolate for use as flavour compounds, bio-medicine, bio-pesticides, anti-microbial agents, as additives in functional foods or in cancer treatment, for production in planta or in micro-organisms.
During this project, we have introduced the entire glucoraphanin biosynthetic pathway into the tobacco plant, Nicotiana benthamiana and in the process elucidated the pathway and identified several key genes. We have shown reconstitution of DHM biosynthesis and in the process discovered three new genes that play key roles in this pathway. We have coupled DHM biosynthesis to glucosinolate biosynthesis and have succeeded in modifying the parent glucosinolate produced to the cancer-preventive glucoraphanin. In addition, we have assigned function to several previously uncharacterised genes in this part of the pathway.
The ability to transfer an entire 13-gene biosynthetic pathway to a heterologous organism is unprecedented and opens up vast opportunities for producing natural products in other species. 4-MSB has been found in a limited number of species in only five families of the Brassicales order. Due to its potent cancer-preventive properties, there is a great interest in investigating if it was possibly to reconstitute this pathway in other species. However, other glucosinolates are potent cancer-preventive agents such as 7-MSH and 8-MSO. These glucosinolates could be produced using the current method with few modifications. The current method can be used to produce any desired glucosinolate for use as flavour compounds, bio-medicine, bio-pesticides, anti-microbial agents, as additives in functional foods or in cancer treatment, for production in planta or in micro-organisms.