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Faculty
Mona Mehdy
Associate Professor in Molecular Cell & Developmental Biology

Email: mmehdy@mail.utexas.edu
Website
Main Office: PAI 2.32
Phone: 471-5806

Alternate Office: PAI 2.38
Alt. Phone: 471-5806

Mailing Address
The University of Texas at Austin - ICMB
1 University Station A6700
103 E. 24th St.
Austin ,TX 78712-1095
Mona Mehdy

Research Summary

In response to pathogens and herbivores, plants employ up-regulation and down-regulation of diverse genes to achieve resistance. Research in my lab centers on two areas: 1) molecular mechanisms of down-regulation of gene expression during the plant defense response and its biological significance; 2) understanding the functions of specific defense-down-regulated genes during normal growth and development. Using both the model plant Arabidopsis and a crop plant, French bean, we have shown that repression of gene expression can occur at the transciptional level or by rapid degradation of mRNAs, depending on the gene. We are especially focused on analyzing the signaling pathway linking pathogen recognition and mRNA degradation. The mRNA for a bean cell wall protein, PvPRP1, is rapidly degraded during the defense response. We have shown that the PvPRP1 protein fails to undergo a cross-linking reaction characteristic of disease resistance, hence providing a biological rationale for its down-regulation. In contrast,an Arabidopsis cell wall protein gene, AGP31,exhibits a novel transcriptional down-regulation to a well-known defense regulator, jasmonic acid. While jasmonic acid activation of genes has been previously identified, our studies on the AGP31 gene will enable exploration of the mechanism of transcriptional repression. The roles of the down-regulated proteins during normal development are being explored by over- and under-expression of the protein in transgenic plants, microarrays, spatial expression and biochemical studies. Our findings suggest interesting roles in the vascular system and rapidly dividing and elongating cells, for the bean PvPRP1 and Arabidopsis AGP31, respectively.