@article{dewey_selote_griffin_dickey_jantz_smith_matthiadis_strable_kestell_smith_2023, title={Cytoplasmic male sterility and abortive seed traits generated through mitochondrial genome editing coupled with allotopic expression of atp1 in tobacco}, volume={14}, ISSN={["1664-462X"]}, DOI={10.3389/fpls.2023.1253640}, abstractNote={Allotopic expression is the term given for the deliberate relocation of gene function from an organellar genome to the nuclear genome. We hypothesized that the allotopic expression of an essential mitochondrial gene using a promoter that expressed efficiently in all cell types except those responsible for male reproduction would yield a cytoplasmic male sterility (CMS) phenotype once the endogenous mitochondrial gene was inactivated via genome editing. To test this, we repurposed the mitochondrially encoded atp1 gene of tobacco to function in the nucleus under the transcriptional control of a CaMV 35S promoter (construct 35S:nATP1), a promoter that has been shown to be minimally expressed in early stages of anther development. The endogenous atp1 gene was eliminated (Δatp1) from 35S:nATP1 tobacco plants using custom-designed meganucleases directed to the mitochondria. Vegetative growth of most 35S:nATP1/Δatp1 plants appeared normal, but upon flowering produced malformed anthers that failed to shed pollen. When 35S:nATP1/Δatp1 plants were cross-pollinated, ovary/capsule development appeared normal, but the vast majority of the resultant seeds were small, largely hollow and failed to germinate, a phenotype akin to the seedless trait known as stenospermocarpy. Characterization of the mitochondrial genomes from three independent Δatp1 events suggested that spontaneous recombination over regions of microhomology and substoichiometric shifting were the mechanisms responsible for atp1 elimination and genome rearrangement in response to exposure to the atp1-targeting meganucleases. Should the results reported here in tobacco prove to be translatable to other crop species, then multiple applications of allotopic expression of an essential mitochondrial gene followed by its elimination through genome editing can be envisaged. Depending on the promoter(s) used to drive the allotopic gene, this technology may have potential application in the areas of: (1) CMS trait development for use in hybrid seed production; (2) seedless fruit production; and (3) transgene containment.}, journal={FRONTIERS IN PLANT SCIENCE}, author={Dewey, Ralph E. and Selote, Devarshi and Griffin, H. Carol and Dickey, Allison N. and Jantz, Derek and Smith, J. Jeff and Matthiadis, Anna and Strable, Josh and Kestell, Caitlin and Smith, William A.}, year={2023}, month={Sep} } @article{selote_matthiadis_gillikin_sato_long_2018, title={The E3 ligase BRUTUS facilitates degradation of VOZ1/2 transcription factors}, volume={41}, ISSN={["1365-3040"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85050368197&partnerID=MN8TOARS}, DOI={10.1111/pce.13363}, abstractNote={AbstractBRUTUS (BTS) is an iron binding E3 ligase that has been shown to bind to and influence the accumulation of target basic helix‐loop‐helix transcription factors through 26S proteasome‐mediated degradation in Arabidopsis thaliana. Vascular Plant One‐Zinc finger 1 (VOZ1) and Vascular plant One‐Zinc finger 2 (VOZ2) are NAM, ATAF1/2 and CUC2 (NAC) domain transcription factors that negatively regulate drought and cold stress responses in plants and have previously been shown to be degraded via the 26S proteasome. However, the mechanism that initializes this degradation is unknown. Here, we show that BTS interacts with VOZ1 and VOZ2 and that the presence of the BTS RING domain is essential for these interactions. Through cell‐free degradation and immunodetection analyses, we demonstrate that BTS facilitates the degradation of Vascular plant One‐Zinc finger 1/2 (VOZ1/2) protein in the nucleus particularly under drought and cold stress conditions. In addition to its known role in controlling the iron‐deficiency response in plants, here, we report that BTS may play a role in drought and possibly other abiotic stress responses by facilitating the degradation of transcription factors, VOZ1/2.}, number={10}, journal={PLANT CELL AND ENVIRONMENT}, publisher={Wiley}, author={Selote, Devarshi and Matthiadis, Anna and Gillikin, Jeffrey W. and Sato, Masa H. and Long, Terri A.}, year={2018}, month={Oct}, pages={2463–2474} } @article{selote_samira_matthiadis_gillikin_long_2015, title={Iron-Binding E3 Ligase Mediates Iron Response in Plants by Targeting Basic Helix-Loop-Helix Transcription Factors}, volume={167}, ISSN={["1532-2548"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84920141665&partnerID=MN8TOARS}, DOI={10.1104/pp.114.250837}, abstractNote={AbstractIron uptake and metabolism are tightly regulated in both plants and animals. In Arabidopsis (Arabidopsis thaliana), BRUTUS (BTS), which contains three hemerythrin (HHE) domains and a Really Interesting New Gene (RING) domain, interacts with basic helix-loop-helix transcription factors that are capable of forming heterodimers with POPEYE (PYE), a positive regulator of the iron deficiency response. BTS has been shown to have E3 ligase capacity and to play a role in root growth, rhizosphere acidification, and iron reductase activity in response to iron deprivation. To further characterize the function of this protein, we examined the expression pattern of recombinant ProBTS::β-GLUCURONIDASE and found that it is expressed in developing embryos and other reproductive tissues, corresponding with its apparent role in reproductive growth and development. Our findings also indicate that the interactions between BTS and PYE-like (PYEL) basic helix-loop-helix transcription factors occur within the nucleus and are dependent on the presence of the RING domain. We provide evidence that BTS facilitates 26S proteasome-mediated degradation of PYEL proteins in the absence of iron. We also determined that, upon binding iron at the HHE domains, BTS is destabilized and that this destabilization relies on specific residues within the HHE domains. This study reveals an important and unique mechanism for plant iron homeostasis whereby an E3 ubiquitin ligase may posttranslationally control components of the transcriptional regulatory network involved in the iron deficiency response.}, number={1}, journal={PLANT PHYSIOLOGY}, author={Selote, Devarshi and Samira, Rozalynne and Matthiadis, Anna and Gillikin, Jeffrey W. and Long, Terri A.}, year={2015}, month={Jan}, pages={273-+} }