CHARACTERIZATION OF TOBACCO MOSAIC VIRUS DIRECTED REPROGRAMMING OF PHLOEM GENE EXPRESSION TO PROMOTE VIRAL PHLOEM LOADING AND SYSTMEIC MOVEMENT

Vascular phloem loading has long been recognized as an essential step in the establishment of a systemic virus infection. Yet little is known about this process and the mechanisms that control it. In this study, an interaction between the replication protein of Tobacco mosaic virus (TMV) and phloem specific auxin/indole acetic acid (Aux/IAA) transcriptional regulators was found to modulate virus phloem loading. Promoter expression studies show TMV 126/183 kDa interacting Aux/IAAs predominantly express and accumulate within the nuclei of phloem companion cells (CC). Furthermore, CC Aux/IAA nuclear localization is disrupted upon infection with an interacting virus but not during infection with a non-interacting virus. In situ analysis of virus spread shows the inability of TMV variants to disrupt Aux/IAA CC nuclear localization correlates with a reduced ability to load into the vascular tissue. Subsequent systemic movement assays also demonstrate that a virus capable of disrupting Aux/IAA localization is significantly more competitive at systemic movement than a non-interacting virus. Similarly, CC expression and over-accumulation of a degradation-resistant-interacting Aux/IAA protein was found to selectively inhibit TMV accumulation and phloem loading. Transcriptional expression studies demonstrate a role for interacting Aux/IAA proteins in the regulation of salicylic acid and jasmonic acid dependent host defense responses as well as virus specific movement factors including pectin methylesterase that are involved in regulating plasmodesmata size exclusion limits and promoting virus cell-to-cell movement. Further characterization of the phloem environment was done using two phloem specific promoters (pSUC2 and pSULTR2;2) to generate epitope-tagged polysomal-RNA complexes. Immuno-purification using the epitope tag allowed us to obtain mRNAs bound to polysomes (the translatome) specifically in phloem tissue. We found the phloem translatome is uniquely altered during TMV infection with 90% and 88% of genes down regulated in the pSUC2 and pSULTR2;2 phloem translatomes, compared to 31% of genes down regulated in the whole plant p35S translatome. Transcripts down regulated in phloem include genes involved in callose deposition at plasmodesmata, host defense responses, and RNA silencing. Combined, these findings indicate TMV reprograms gene expression within the vascular phloem as a means to enhance phloem loading and systemic spread.

Violence against Women Policy and Practice in Uganda - Promoting Justice within the Context of Patriarchy

The goal of this study was to understand how and whether policy and practice relating to violence against women in Uganda, especially Uganda’s Domestic Violence Act of 2010, have had an effect on women’s beliefs and practices, as well as on support and justice for women who experience abuse by their male partners. Research used multi-sited ethnography at transnational, national, and local levels to understand the context that affects what policies are developed, how they are implemented, and how, and whether, women benefit from these. Ethnography within a local community situated global and national dynamics within the lives of women. Women who experience VAW within their intimate partnerships in Uganda confront a political economy that undermines their access to justice, even as a women’s rights agenda is working to develop and implement laws, policies, and interventions that promote gender equality and women’s empowerment. This dissertation provides insights into the daily struggles of women who try to utilize policy that challenges duty bearers, in part because it is a new law, but also because it conflicts with the structural patriarchy that is engrained in Ugandan society. Two explanatory models were developed. One explains factors relating to a woman’s decision to seek support or to report domestic violence. The second explains why women do and do not report DV. Among the findings is that a woman is most likely to report abuse under the following circumstances: 1) her own, or her children’s survival (physical or economic) is severely threatened; 2) she experiences severe physical abuse; or, 3) she needs financial support for her children. Research highlights three supportive factors for women who persist in reporting DV. These are: 1) the presence of an “advocate” or support 2) belief that reporting will be helpful; and, 3) lack of interest in returning to the relationship. This dissertation speaks to the role that anthropologists can play in a multi-disciplinary approach to a complex issue. This role is understanding – deeply and holistically; and, articulating knowledge generated locally that provides connections between what happens at global, national and local levels.