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<p class="MsoNormal"><span style="font-size:11.0pt">Dear all,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Please join us in <a href="https://map.arizona.edu/107">
<b>Marley 230</b></a> <b>at 4:00 PM</b> <b>today</b> for a seminar presented by Cristian Salazar De Leon, School of Plant Sciences, University of Arizona. Dr. Jesse Woodson will serve as the host.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Zoom link: <a href="https://arizona.zoom.us/j/84253432688">
https://arizona.zoom.us/j/84253432688</a> (password: <b>SPLS2025</b>).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Refreshments will be provided in the Marley Lobby at 3:30 PM.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt">Title: Role of inosine 5’-monophosphate dehydrogenase in
<sup>1</sup>O<sub>2</sub> signaling in <i>Arabidopsis thaliana</i><o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt">Abstract:</span></b><span style="font-size:11.0pt"> Plants are sessile organisms and have evolved cellular mechanisms to sense and respond to their environment. One way they can do this is through their
energy producing organelles, which produce steady-state levels of reactive oxygen species (ROS). Increased levels of ROS can indicate changes or stressors in their environment and act as signals that trigger a cellular response. Specifically, the chloroplast
produces a type of ROS called singlet oxygen (<sup>1</sup>O<sub>2</sub>), which acts as a retrograde signal from the chloroplast to the nucleus to initiate a transcriptional response to stress. Chloroplast
<sup>1</sup>O<sub>2 </sub>retrograde signaling can be monitored in the <i>Arabidopsis thaliana</i>
<i>plastid</i> <i>ferrochelatase</i> <i>two</i> (<i>fc2</i>) mutant, which produces a burst of
<sup>1</sup>O<sub>2</sub> in the chloroplast under cycling light conditions causing rapid chloroplast degradation and cell death. A genetic suppressor screen for mutants that rescued the
<i>fc2</i> phenotype which identified 24 <i>ferrochelatase two suppressor</i> (<i>fts</i>) candidates. Two of these
<i>fts</i> mutants (<i>fts2</i> & <i>fts13</i>) affect a nucleotide metabolism gene, inosine 5’-monophosphate dehydrogenase 1 (impdh1), which encodes one of two cytoplasmic enzymes necessary for de novo guanosine monophosphate (GMP) synthesis. My research project
aims to understand the role of impdh1 in <sup>1</sup>O<sub>2</sub> signaling in <i>
Arabidopsis thaliana</i>.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">This will be the final seminar of the semester. Thank you all for your participation throughout the semester, and I wish everyone a smooth and successful finals week.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt;font-family:"Courier New";mso-ligatures:none">===============================================================<br>
</span><b><span style="font-size:20.0pt;font-family:"Vladimir Script";mso-ligatures:none">Zhongguo Xiong</span></b><span style="font-size:10.0pt;font-family:"Courier New";mso-ligatures:none"> <br>
School of Plant Sciences BIO5 Institute<br>
BIO5 Email: <span style="color:blue"><a href="mailto:zxiong@arizona.edu"><span style="color:blue">zxiong@arizona.edu</span></a></span>
<br>
Phone: (520)-621-9869<br>
Forbes 303, P.O. box 210036 Fax: (520)-621-7186<br>
University of Arizona <br>
Tucson, AZ 85721-0036 <span style="color:blue"><a href="http://ag.arizona.edu/~zxiong"><span style="color:blue">http://ag.arizona.edu/~zxiong</span></a></span><br>
===============================================================</span><span style="font-size:11.0pt;mso-ligatures:none"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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