Christie Williams

Adjunct Associate Professor

Department: Agronomy
Phone: 765.494.6763
Office: WSLR 236
E-mail: cwilliams@purdue.edu

​​​Curriculum Vitae​




Biography:

Christie earned her bachelor’s degree in Genetics at the University of California-Davis and her Ph.D. at UC-Berkeley. As a Research Molecular Biologist with the USDA Agricultural Research Service, she is an Adjunct Associate Professor and on the faculty of Purdue University. She mentors graduate students and postdoctoral researchers through the Department of Agronomy in her lab on campus in Whistler Hall.

Current Research:

Research in the Williams lab focuses on characterizing the interactions between wheat and its major insect pest, the Hessian fly. Three of the newest genes conferring resistance to Hessian fly larvae (H31, H32 and H33) were identified, mapped to specific chromosomal regions and flanked with DNA markers appropriate for marker-assisted breeding. Mechanisms leading to wheat resistance or susceptibility are being investigated at the levels of gene expression (RNA-Seq, quantitative real-time PCR, viral-induced gene silencing), proteomics (immuno hybridization, glycomic binding microarrays) and promoter analysis (motif identification, transcription factor quantification). To understand gene function during resistance, transgenic wheat and Brachypodium plants have been produced with cloned promoters driving genes encoding defense proteins to test the tissue specificity of expression and the effectiveness against larvae. Ongoing investigations of the effect of wheat defense responses on Hessian fly larvae include identifying damage to the insect midgut (scanning electron microscopy), characterizing insecticidal proteins (feeding assays) and analysis of microRNA expression (RNA-Seq).​

Graduate Students:

Abdelrahman Awad (PhD)

Recent Publications:

Liu, X., Williams, C. E, Nemacheck, J.A., Wang, H., Subramanyam, S., Zheng, C. and Chen, M. C. Reactive oxygen species are involved in plant defense against a gall midge. Plant Physiol. 152: 985-999. 2010.
 
Shukle R. H., Subramanyam, S, and Williams, C. E. Ultrastructural changes in the midgut of Hessian fly larvae feeding on resistant wheat. J. Insect Physiology 56: 754-760. 2010.
 
Yu, G. T., Williams, C. E., Harris, M. O., Cai, X., Mergoum, M. and Xu, S. S. Development and validation of molecular markers closely linked to H32 for resistance to Hessian fly in wheat. Crop Science 50: 1325-1332. 2010.
 
Kosma, D. K., Nemacheck, J. A., Jenks, M. A. and Williams, C. E. Changes in properties of the wheat leaf cuticle during interactions with Hessian fly. Plant Journal 63: 31-43. 2010.
 
Xu, S. S., Chu, C. G., Harris, M. O. and Williams, C. E. Comparative analysis of genetic background in eight near-isogenic wheat lines with different H genes conferring resistance to Hessian fly. Genome 54:81-89. 2011.
 
Williams, C. E., Nemacheck, J. A., Shukle, J. T., Subramanyam, S., Saltzmann, K. D. and Shukle, R. H. Induced epidermal permeability modulates resistance and susceptibility of wheat seedlings to herbivory by Hessian fly larvae. J. Experimental Botany 62: 4521-4531. 2011.
 
Shukle, R. H., Subramanyam, S. and Williams, C. E. Effects of antinutrient proteins on Hessian fly (Diptera: Cecidomyiidae) larvae. J. Insect Physiology 58: 41-48. 2011.
 
Baluch, S. D., Ohm, H. W., Shukle, J. T. and Williams, C. E. Obviation of wheat resistance to the Hessian fly through systemic induced susceptibility. J. Economic Entomology 105: 642-650. 2012.
 
Subramanyam, S., Cheng, C., Shukle, J., and Williams, C. E. Hessian fly larval attack triggers elevated expression of disease resistance dirigent-like protein-encoding gene, HfrDir, in resistant wheat. Arthropod-Plant Interactions 7: 389-402. 2013.
 
Khajuria, C., Williams, C. E., El Bouhssini, M., Whitworth, R., Richards, R., Stuart, J., and Chen, M. S. Deep sequencing and genome-wide analysis reveals the expansion of MicroRNA genes in the gall midge Mayetiola destructor. BMC Genomics 14: 187-197. 2013.
 
Shreve, J., Shukle, R., Subramanyam, S., Johnson, A., Schemerhorn, B., Williams, C. E., and Stuart, J. A genome-wide survey of small interfering RNA and microRNA pathway genes in a galling insect. Journal of Insect Physiology 59: 367-376. 2013.