Targeting the role of benzoxazinoid genes in maize-aphid resistance
Benzoxazinoids are compounds toxic to aphids and other insects found in maize and other grasses stored as inactive glucosides. Benzoxazinoids are activated by a glucosidase upon herbivore feeding. Previous research identified a Quantitative Trait Locus (QTL) on Chromosome 1 in maize that is thought to affect benzoxazinoid biosynthesis. Three genes within the QTL (Bx10a-c) were identified as methyltransferases and are thought to catalyze the methylation of DIMBOA-Glc (a benzoxazinoid) to HDMBOA-Glc. To prove that these genes play a role in benzoxazinoid biosynthesis, we attempted to isolate loss-of-function knockout alleles induced by the transposable element Dissociation (Ds). We took a reverse genetic, PCR-based approach to screen for Ds insertions in the three target genes, as well as two intermediate genes. A screening population was generated by crossing a line known to carry a closely linked Ds insertion crossed to wild-type W22 inbred females. Should a Ds insertion be found within Bx10a-c we will self pollinate that plant and use the progeny in an aphid assay. Should an insertion be found surrounding Bx10a-c we will self pollinate that plant and use the progeny as new Ds donors in future test cross populations. Through reverse genetic screens of testcross populations, we hope to remobilize the closest Ds donor into the three gene targets (Bx10a-c) in order to compare the knockout alleles to a wild type in terms of benzoxazinoid synthesis.
Coming to work alongside leading professionals in the field of plant science in one of the top facilities in the world was a daunting thought, especially for a high school student. I was honored to receive an internship position in Dr. Jander’s lab and eager to learn more about a potential career path. Because I enjoyed my high school chemistry and biology classes and I have an interest in environmental and biological law, I saw this internship as a way to learn more about the field that I may want to go on to study and pursue a career in. Looking back, my time at the Boyce Thompson Institute has delineated in my mind a potential career path, as well as given me many laboratory, writing, and presentation skills that I believe will prove necessary in my studies. Working with a mentor made my experience at BTI successful, as I knew I had someone to direct my questions and concerns, and that I would always be met with acceptance and guidance.