Graduate Student University of Vermont Burlington, Vermont
Body of Abstract: Roots function to take up water and nutrients as well as mediate microbe interactions with the surrounding soil environment to allow for plant development and stress response. Previous work in our lab has shown that VTI13 is a Soluble N-ethylmaleimide sensitive factor Attachment Receptor (SNARE) essential for root hair growth and root epidermal cell wall organization (Larson et al., 2014). VTI13 localizes to the membrane of early endosomes and the tonoplast, implying its role in the delivery of proteins to the lytic vacuole. Proteomic analysis of the VTI13-labeled endosome revealed potential cargo from three major classes: stress-related proteins, plasma membrane proteins, and proteins needed for clathrin-mediated endocytosis (Jha et al., unpublished). qRT-PCR analysis showed that several of these genes were mis-regulated in the vti13 background (Jha et al., unpublished), suggesting a transcriptional co-regulation mechanism between the VTI13 trafficking pathway and these potential cargo protein genes. The presence of stress-related proteins in the VTI13 proteome prompted a characterization of the VTI13 pathway in response to stressful environmental conditions in roots. The focus of this work is to identify the role of VTI13 in response to a variety of abiotic stresses including NaCl, mannitol, and pH. My initial findings indicate that the growth of vti13 root hairs was less sensitive to 30 mM NaCl than that of wild-type seedlings, suggesting a potential difference in the sensitivity to salt between vti13 and wild-type. This study provides initial evidence that the VTI13 trafficking pathway to the vacuole intersects with an abiotic stress response of seedling roots in Arabidopsis.