Regulation of herbivore-induced defenses responses by benzoxazinoids in Zea mays
Final Report Abstract
Plants are a masters at managing growth and development, even when they are encountering multiple simultaneous stresses such as insect feeding and drought. A key component of these plant responses are signaling pathways that allow a balanced use of the available resources to maximize growth. Every stage of the plant life cycle is regulated by an interplay of small molecules that mediate interactions between different plant parts and provide information about ongoing stresses. In maize, the most economically important crop plant in the United States, toxic molecules called benzoxazinoids have an essential role in defense against insect feeding and fungal infections. However, in addition to these direct defensive functions, benzoxazinoids also regulate other aspects of plant metabolism, including growth and flowering time. To date, the mechanisms by which benzoxazinoids help to balance inputs into different aspects of plant physiology remain uninvestigated. Thus, if we find previously unknown regulatory mechanisms of maize defense responses, there are likely practical applications in producing plants that are naturally more resistant to insect attack. Another aspect of this research that may lead to intellectual proper is the link that benzoxazinoids provide between plant defense and plant growth. This growth/defense tradeoff, which is characteristic of many plants, can limit overall yield in agricultural production settings where otherwise growth-limiting inputs are not necessarily a concern. In this research project we identified that benzoxazinoids are involved in blue light perception as well as in the regulation of other putative downstream defense compounds. Additionally, I observed how benzoxazinoid formation itself is regulated by three functionally enzymes, called indole-3-glycerol phosphate synthases.
Publications
- (2018) Beyond defense: multiple functions of benzoxazinoids in maize metabolism. Plant and Cell Physiology 59 (8):1528-1537
Zhou S, Richter A, Jander G
(See online at https://doi.org/10.1093/pcp/pcy064) - Indole-3-glycerolphosphate synthase, a branchpoint for the biosynthesis of tryptophan, indole, and benzoxazinoids in maize. The Plant Journal
Richter A, Powell AF, Mirzaei M, Wang LJ, Movahed N, Miller JK, Piñeros MA, Jander G
(See online at https://doi.org/10.1111/tpj.15163)
