Understanding the roles of the benzoxazinoid genes Bx10a, Bx10b, and Bx10c in maize-aphid resistance

Project Summary

Natural defense mechanisms are crucial for protecting plants against biological threats.   Benzoxazinoids are secondary metabolites in maize that are stored as inactive glucosides and, when enzymatically activated by glucosidase, act as defense mechanisms against insects. DIMBOA-Glc is an important benzoxazinoid in maize that functions in a larger biochemical pathway involved in the methylation of DIMBOA-Glc to HDMBOA-Glc and the rapid conversion of active HDMBOA to MBOA. All three of these compounds are lethal to insects and the Rhopalosiphum maidis (corn leaf aphid), a major maize-insect threat, is susceptible to these compounds. Three maize genes, Bx10a, Bx10b, andBx10c, located on chromosome 1 are believed to be responsible for the methylation of DIMBOA-Glc to HDMBOA-Glc, but little is known about the individual roles of these genes in this benzoxazinoid pathway. A Dissociation (Ds) transposon insertion was identified near these three target genes and thisDs transposon can be mobilized in the presence of Activator (Ac) transposon which promotes Dsmovement. A  Ds transposon insertion causes a genetic mutation that could inhibit gene expression of each target gene. My project involves conducting a PCR-based, reverse-genetic screen of a testcross population created to promote Ds transposition into any of the three target genes. If Ds insertions occur, more information can be gathered about the role each target gene plays in this benzoxazinoid pathway. Researching natural insect resistance mechanisms in this agronomical, globally valued crop could optimize plant-insect resistance in the future without utilizing environmentally degrading pesticides, promoting sustainable growth of the agricultural sector.

My Experience

During my summer internship at the Boyce Thompson Institute for Plant Research I became more in tune with my working style and confident in my abilities to work in a professional research setting. My mentor Kevin Ahern exemplified effective mentorship and through our collaboration I learned many lab techniques and research skills that will be extremely beneficial in college. When employing these new skills I became more familiar with the successes and failures experienced in any research setting and how to adapt and troubleshoot when things do not go as planned. This internship has aided in the development of my interests in plant biology and the role plant genetics plays in human health.Everything I have experienced at BTI has reaffirmed my interest in pursuing research in college.