Genomic stability in response to high versus low linear energy transfer radiation in Arabidopsis thaliana.

Low linear energy transfer (LET) gamma rays and high LET HZE (high atomic weight, high energy) particles act as powerful mutagens in both plants and animals. DNA damage generated by HZE particles is more densely clustered than that generated by gamma rays. To understand the genetic requirements for resistance to high versus low LET radiation, a series of Arabidopsis thaliana mutants were exposed to either 1GeV Fe nuclei or gamma radiation. A comparison of effects on the germination and subsequent growth of seedlings led us to conclude that the relative biological effectiveness (RBE) of the two types of radiation (HZE versus gamma) are roughly 3:1. Similarly, in wild-type lines, loss of somatic heterozygosity was induced at an RBE of about a 2:1 (HZE versus gamma). Checkpoint and repair defects, as expected, enhanced sensitivity to both agents. The "replication fork" checkpoint, governed by ATR, played a slightly more important role in resistance to HZE-induced mutagenesis than in resistance to gamma induced mutagenesis

Telomere dynamics and fusion of critically shortened telomeres in plants lacking DNA ligase IV

In the absence of the telomerase, telomeres undergo progressive shortening and are ultimately recruited into end-to-end chromosome fusions via the non-homologous end joining (NHEJ) double-strand break repair pathway. Previously, we showed that fusion of critically shortened telomeres in Arabidopsis proceeds with approximately the same efficiency in the presence or absence of KU70, a key component of NHEJ. Here we report that DNA ligase IV (LIG4) is also not essential for telomere joining. We observed only a modest decrease (3-fold) in the frequency of chromosome fusions in triple tert ku70 lig4 mutants versus tert ku70 or tert. Sequence analysis revealed that, relative to tert ku70, chromosome fusion junctions in tert ku70 lig4 mutants contained less microhomology and less telomeric DNA. These findings argue that the KU-LIG4 independent end-joining pathway is less efficient and mechanistically distinct from KU-independent NHEJ. Strikingly, in all the genetic backgrounds we tested, chromosome fusions are initiated when the shortest telomere in the population reaches ∼1 kb, implying that this size represents a critical threshold that heralds a detrimental structural transition. These data reveal the transitory nature of telomere stability, and the robust and flexible nature of DNA repair mechanisms elicited by telomere dysfunction

Taking the Next Step: Building an Arabidopsis Information Portal

The Arabidopsis Information Portal (AIP), a resource expected to provide access to all community data and combine outputs into a single user-friendly interface, has emerged from community discussions over the last 23 months. These discussions began during two closely linked workshops in early 2010 that established the International Arabidopsis Informatics Consortium (IAIC). The design of the AIP will provide core functionality while remaining flexible to encourage multiple contributors and constant innovation. An IAIC-hosted Design Workshop in December 2011 proposed a structure for the AIP to provide a framework for the minimal components of a functional community portal while retaining flexibility to rapidly extend the resource to other species. We now invite broader participation in the AIP development process so that the resource can be implemented in a timely manner.This is the publisher’s final pdf. The published article is copyrighted by the American Society of Plant Biologists and can be found at: http://www.plantcell.org/

The next generation of training for arabidopsis researchers: Bioinformatics and Quantitative Biology

It has been more than 50 years since Arabidopsis (Arabidopsis thaliana) was first introduced as a model organism to understand basic processes in plant biology. A well-organized scientific community has used this small reference plant species to make numerous fundamental plant biology discoveries (Provart et al., 2016). Due to an extremely well-annotated genome and advances in high-throughput sequencing, our understanding of this organism and other plant species has become even more intricate and complex. Computational resources, including CyVerse,3 Araport,4 The Arabidopsis Information Resource (TAIR),5 and BAR,6 have further facilitated novel findings with just the click of a mouse. As we move toward understanding biological systems, Arabidopsis researchers will need to use more quantitative and computational approaches to extract novel biological findings from these data. Here, we discuss guidelines, skill sets, and core competencies that should be considered when developing curricula or training undergraduate or graduate students, postdoctoral researchers, and faculty. A selected case study provides more specificity as to the concrete issues plant biologists face and how best to address such challenges

Arabidopsis bioinformatics resources: the current state, challenges, and priorities for the future

Effective research, education, and outreach efforts by the Arabidopsis thaliana community, as well as other scientific communities that depend on Arabidopsis resources, depend vitally on easily available and publicly-shared resources. These resources include reference genome sequence data and an ever-increasing number of diverse data sets and data types. TAIR (The Arabidopsis Information Resource) and Araport (originally named the Arabidopsis Information Portal) are community informatics resources that provide tools, data, and applications to the more than 30,000 researchers worldwide that use in their work either Arabidopsis as a primary system of study or data derived from Arabidopsis. Four years after Araport’s establishment, the IAIC held another workshop to evaluate the current status of Arabidopsis Informatics and chart a course for future research and development. The workshop focused on several challenges, including the need for reliable and current annotation, community-defined common standards for data and metadata, and accessible and user-friendly repositories / tools / methods for data integration and visualization. Solutions envisioned included (1) a centralized annotation authority to coalesce annotation from new groups, establish a consistent naming scheme, distribute this format regularly and frequently, and encourage and enforce its adoption. (2) Standards for data and metadata formats, which are essential, but challenging when comparing across diverse genotypes and in areas with less-established standards (e.g. phenomics, metabolomics). Community-established guidelines need to be developed. (3) A searchable, central repository for analysis and visualization tools. Improved versioning and user access would make tools more accessible. Workshop participants proposed a “one-stop shop” website, an Arabidopsis “Super-Portal” to link tools, data resources, programmatic standards, and best practice descriptions for each data type. This must have community buy-in and participation in its establishment and development to encourage adoption

Broadening the impact of plant science through innovative, integrative, and inclusive outreach

Population growth and climate change will impact food security and potentially exacerbate the environmental toll that agriculture has taken on our planet. These existential concerns demand that a passionate, interdisciplinary, and diverse community of plant science professionals is trained during the 21st century. Furthermore, societal trends that question the importance of science and expert knowledge highlight the need to better communicate the value of rigorous fundamental scientific exploration. Engaging students and the general public in the wonder of plants, and science in general, requires renewed efforts that take advantage of advances in technology and new models of funding and knowledge dissemination. In November 2018, funded by the National Science Foundation through the Arabidopsis Research and Training for the 21st century (ART 21) research coordination network, a symposium and workshop were held that included a diverse panel of students, scientists, educators, and administrators from across the US. The purpose of the workshop was to re‐envision how outreach programs are funded, evaluated, acknowledged, and shared within the plant science community. One key objective was to generate a roadmap for future efforts. We hope that this document will serve as such, by providing a comprehensive resource for students and young faculty interested in developing effective outreach programs. We also anticipate that this document will guide the formation of community partnerships to scale up currently successful outreach programs, and lead to the design of future programs that effectively engage with a more diverse student body and citizenry.This white paper is published as Friesner, Joanna, Adán Colón‐Carmona, Alexandra M. Schnoes, Anna Stepanova, Grace Alex Mason, Gustavo C. Macintosh, Hemayat Ullah et al. "Broadening the impact of plant science through innovative, integrative, and inclusive outreach." Plant Direct 5, no. 4 (2021): e00316. doi:10.1002/pld3.316</p

Telomere dynamics and fusion of critically shortened

telomeres in plants lacking DNA ligase I

Labor in the Food System: A View from INFAS

The Inter-institutional Network for Food, Agriculture and Sustainability (INFAS or "the Network"), initiated informally in 2008 and formalized in 2011, encompasses a broad group of practitioners, primarily in academic institutions, who work individually on a diverse range of topics in agricultural and food system sustainability. INFAS grew from a shared vision to expose the challenges facing the transformation of agriculture and our global food system, including the sometimes competing interests of labor, producers, and consumers in the food system. From the start, the Network was envisioned to include activists in collaboration with academics in order to broadly improve the economic, environmental, and social sustainability of the food system by spanning disciplinary and institutional boundaries, convening diverse stake-holders, and linking knowledge with action. We envision an environmentally sustainable and socially just U.S. food system. This requires that race, class, and gender no longer determine health outcomes, social status, or economic opportunity, and that healthy, restored agroecosystems and fisheries are achievable...