<div dir="ltr"><div><img src="cid:ii_kyw3ngi90" alt="image.png" width="531" height="141"><br><br></div><div></div><div>
<p class="MsoNormal" style="margin:0in;vertical-align:baseline;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:107%;color:black">Welcome back all,<span></span></span></p>
<p class="MsoNormal" style="margin:0in;vertical-align:baseline;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:107%;color:black"> <span></span></span></p>
<p class="MsoNormal" style="margin:0in;vertical-align:baseline;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:107%;color:black">The first seminar by Mariela Garcia Arrendondo at the University of Massachusetts-Amherst will be presented next Monday (1/31). Please join us between 12-1 pm (pacific) via zoom. <span></span></span></p>
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<font size="2"><span style="font-family:arial,sans-serif"><a href="https://ucmerced.zoom.us/j/175736103" target="_blank">https://ucmerced.zoom.us/j/175736103</a></span></font>
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<p class="MsoNormal" style="margin:0in;vertical-align:baseline;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:107%;color:black"> <span></span></span></p>
<p class="MsoNormal" style="vertical-align:baseline;margin:0in 0in 8pt;line-height:107%;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:107%;color:black">Title: A Glimpse Underground: Sensing Functionally Distinct Microsites within the Rhizosphere <span></span></span></p><span style="font-size:12pt;line-height:106%;color:black"><span></span></span>
<p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black">Abstract: Understanding the dynamics and vulnerability of mineral-organic interactions is critical for projecting climate change impacts on soil fertility and carbon storage. Plant roots and associated microbes release an array of reactive rhizodeposits, potentially both forming and disrupting protective mineral-organic associations (MOAs) in the surrounding soil. But our ability to measure and predict the impact of rhizodeposits on the dynamics of MOAs in the rhizosphere remains limited. Here, we combined an innovative use of a diverse series of micro(bio)sensors into a succession of experiments to assess the fate of MOAs within dynamic, biogeochemically distinct microenvironments in the rhizosphere. We then combined this in-situ micro(bio)sensors approach with mass spectrometry to follow the impact of single roots on the dynamics of protective iron (Fe)-organic matter associations. <br><br>Continuous, high-resolution monitoring of growing and maturing Avena sativa roots from collection of microdialysis, micro-electrode, and micro(bio)sensor measurements revealed dramatic changes along transects, from root tip to uptake zone, and mature suberized zones. Root tips showed a sharp decline in pH and redox potential as well as a concurrent increase in microbial activity, Fe and DOC concentrations. As roots matured, microbial activity decreased while pH and redox potential recovered followed by a decline in Fe and DOC concentrations. Metabolite analysis via tandem mass spectrometry (LC-FT-ICR-MS) shows a progression of functionally distinct rhizodeposits such as organic acids, amino acids, and lipids from root tips to more mature zones. These changes in microenvironment conditions along the root axis hold the potential for disrupting protective Fe-organic matter associations. <br><br>Our results suggest that the fate of MOAs in the rhizosphere depends, in part, on the distinct nature of transient microenvironments emerging around different root segments. Our micro(bio)sensor approach provides the unique ability to systematically assess the dynamic interplay between roots, microbes, and minerals within these microenvironments. Future development and application of this combination of micro(bio)sensors can further provide us with insight into the role of roots in soil carbon storage and nutrient acquisition. <br></span></p><img src="cid:ii_kyw3sps91" alt="image.png" style="margin-right: 0px;" width="216" height="202"><br><br><p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black">Bio: Mariela is originally from Fort Worth, TX and joined the Keiluweit lab in Fall of 2016 after finishing her undergrad at Cornell University. Her BS was in Science of Earth Systems, which she concluded with an honors thesis in soil organic matter regeneration on desertified grassland soils. She was awarded a Spaulding-Smith Fellowship and a National Science Foundation Graduate Research Program fellowship for her research at UMass Amherst aimed to further our understanding of the mechanisms induced at the rhizosphere between soil minerals and plant roots and their associated microbes. Specifically, how rhizosphere processes can drive mineral-organic association vulnerability in soils and their potential for carbon storage. Mariela also co-founded an initiative during her time at UMass, BRiDGE, which aims to increase the representation and visibility of early career scientists from underrepresented groups in departmental seminars to help combat attrition of underrepresented graduate students. She has worked on the Board of Advisors at the Eagle Eye Institute in Holyoke, MA where her outreach focuses on connecting middle school students with soils while taking them on soil hikes to learn about soil health and the local food systems. Mariela firmly believes that none of our environmental solutions will be effective if we continue to lack the voices of those most affected by a changing climate. In the future, she would like to work as a soil scientist either advising policy or developing projects focused on bridging the gap between environmental research in soil biogeochemistry and its application (e.g., sustainable land development, remediation). During her free time, she enjoys cooking, gardening, and painting.</span></p><p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black"><br></span></p><p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black">Sincerely,<br></span></p><p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black">co-host: KJ Min & Manisha Dolui<span></span></span></p>
<p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black">faculty coordinator: Asmeret Asefaw Berhe</span></p><p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black"><br></span></p><p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black">-----</span></p><p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black">Spring 2022 Enviro-lunch schedule</span></p><img src="cid:ii_kyw3vzkf2" alt="image.png" width="561" height="439"><br><br><p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black"></span></p><p class="MsoNormal" style="line-height:106%;vertical-align:baseline;margin:0in 0in 8pt;font-size:11pt;font-family:"Calibri",sans-serif"><span style="font-size:12pt;line-height:106%;color:black"><span></span></span></p><br></div></div>