Chapter 15: MOA Part 1: Lipid Synthesis Inhibitors & Seedling Shoot Growth Inhibitors
15.11 Summary
Fatty acid synthesis and elongation are highly important pathways in plants because the end products are critical components of membranes, cutin, suberin, and waxes. Fatty acid synthesis chain length up to 18 carbons) is inhibited by the Group 1 Site of Action herbicides, which inhibit ACCase, the first enzyme of the pathway. Fatty acid elongation (16 and 18 carbon fatty acids are elongated up to 34 carbons) is inhibited by the Group 8 and Group 15 herbicide Sites of Action. This chapter summarized key concepts for each class, including damage symptoms seen in susceptible plants. Resistance to these groups of herbicides has been identified in several weedy species.
Key Takeaways
Key takeaways from this chapter include:
- Lipid synthesis and elongation are critical to cell membranes and other plant structures.
- Group 1 Site of Action herbicides are considered Lipid Synthesis Inhibitors which inhibit ACCase, an important enzyme involved in fatty acid synthesis.
- Group 1 herbicides include three chemical families, commonly referred to as the ‘fops’, ‘dims’ and ‘dens’.
- Group 8 and Group 15 herbicides are considered Seedling Shoot Growth Inhibitors that work by inhibiting fatty acid elongation.
- Several weeds have exhibited resistance to these groups of herbicides.