Identification of putative caenorhabditis elegans mutants involved in chalcone resistance

Plant Parasitic Nematodes (PPNs) cause an enormous annual monetary loss (Li et al., 2007). Thus, new and safe alternatives to control PPN are needed. Previous work identified two organic chalcones, Chalcone 17 and Chalcone 25, as effective nematicidals (Attar et al., 2012 and Calderón-Urrea, personal communication); however, their mechanism of action is not known. This lack of knowledge is addressed by investigating whether or not there is a genetic pathway that enables C. elegans to overcome the lethal effects of chalcones. We hypothesize that susceptibility to chalcones is due to the action of the chalcone on a protein product, and therefore mutations on the gene encoding that protein will render the chalcone action ineffective. Identifying and isolating mutants was accomplished by screening mutagenized C. elegans for survivors in the presence of chalcones and then testing survivor nematodes for the presence of transmissible chalcone-resistance mutations. We identified two putative resistant mutants with Chalcone 17 and seven putative resistant mutants with Chalcone 25. Then, we determined that we had uncovered two recessive mutants resistant to Chalcone 17 and six dominant mutants and one recessive mutant resistant to Chalcone 25. Further analysis will identify the DNA sequence involved with the mutation using a whole genome sequencing (WGS) approach. Our work will contribute to the understanding of the chalcones’ mechanism of action in killing the nematodes.