Adjunct Associate Professor
Office: WSLR 236
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
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).
Abdelrahman Awad (PhD)
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.
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: