Botany

John Zaborsky, along with fellow UW Botany alumni Jeff Rose, Ricardo Kriebel, Bryan Drew, and Ken Sytsma have published a paper on the phylogenetics and biogeography of Sesamothamnus (Pedaliaceae) in American Journal of Botany. A phylogenetic tree based on 512 nuclear genes and entire plastomes was generated for Sesamothamnus. The nuclear and plastome data provided congruent phylogenies and showed that the species restricted to northeast Africa are sister to the species in southern Africa. Sesamothamnus shows a classic distributional pattern between these arid areas: the African Arid Corridor (AAC) disjunction. A hypothesis explaining this disjunction posits the former existence of a corridor of arid habitats that linked the two areas. Searching the literature, the authors found 73 examples of vascular plants that exhibit this distribution. Along with Sesamothamnus, time-calibrated splits were obtained for these groups, ranging from 34 Ma to the Pleistocene, with the majority dated to the late Miocene, Pliocene, and Pleistocene.

Most clades, including Sesamothamnus, appear associated with waves of aridification that shaped the biota of Africa during this time, with the corridor opening and closing repeatedly. The rise of C4 and CAM photosynthesis, evolution of succulence and spiny stems, and the diversification of bovids also occurred during this time. The data show that the AAC formed and reformed many times, allowing the ancestors of these plants to frequently migrate from the southwest to the northeast. The pattern is complicated, and phylogenetic studies of widely distributed African genera may reveal more AAC disjunctions between sister taxa.
https://bsapubs.onlinelibrary.wiley.com/doi/10.1002/ajb2.70192

We'd like to congratulate grad student Freyja Moser (Muir Lab) who was awarded an NSF GRFP!
Way to go, Freyja!

We are proud of Botany graduate student Zoe Ryan, who was selected to be a Lead Teaching Mentor for the L&S Teaching Mentors Program! And we are also proud of grad student Shaneya Miriyagalla, who is a Teaching Mentor in the program. Each Teaching Mentor is chosen through a competitive selection process for their enthusiasm and capacity to help others develop as effective and equitable teachers. They not only serve as role models, but also as sources of support and knowledge for both new and returning TAs.
https://teachlearn.ls.wisc.edu/ta-programming/teaching-mentors/

Congrats to Professor Shan He, whose final postdoctoral project at Princeton was published in Nature Cell Biology last month!
From Dr He: "Biomolecular condensates are non-membrane-bound organelles formed through liquid-liquid phase separation. Despite their importance for biological functions, the mechanisms by which condensate size is actively controlled remain unclear. Using the pyrenoid, a condensate that enhances photosynthetic CO2 fixation in eukaryotic algae, as a model system, we identified a kinase-based mechanism that actively regulates condensate size. Our work establishes a strong foundation for further studies of condensate regulation across a wide range of biological systems."
https://www.nature.com/articles/s41556-026-01908-w

A summary of the work can be found at https://molbio.princeton.edu/news/2026/key1-unlocks-pyrenoid

KEY1 unlocks the pyrenoid “The regulation of condensate assembly and disassembly is a major outstanding question in the field, and this paper is a beautiful elucidation of how that works for the pyrenoid,” says Clifford Brangwynne. Pictured are first authors Shan He and Linnea Lemma.

A collaboration between Sam Anderson (McCulloh Lab) and Dr. Dave Rogers at UW-Parkside (A UW-Botany alumnus) combined plant traits and historical survey data of Wisconsin to show that changing forest composition is impacting how Wisconsin forests interact with disturbance and stress. While closely related tree species still tend to grow on similar sites, our findings demonstrate marked shifts in drought tolerance, fire adaptation, and more acquisitive functional strategies of Wisconsin forests.

Functional and Phylogenetic Implications of Canopy Mesophication in Temperate Hardwood Forests Mesophication describes the shifting of forests fire-adapted systems to those dominated shaded-adapted species, but the functional underpinnings of forest mesophication have received less quantitativ...

From the Pringle Lab: Fly agaric mushrooms (Amanita muscaria) are invasive in South Africa, and an international collaboration reveals their rich chemistry may be a mechanism used by the fungi to spread. However, fly agarics appear to kill nematodes, not flies!

Equipped for success: genomes and metabolomes of the European Amanita muscaria are conserved in its novel South African range Plants and soils have been moved around the world for centuries, but invasive mushrooms receive scant attention. The Amanita muscaria species complex was introduced to South Africa in the context of...

Joseph Walston (Cameron Lab) was one of four graduate students to win the campus-wide UW—Madison Award for Mentoring Undergraduates in Research, Scholarly and Creative Activities given by the Office of the Provost and the Division for Teaching and Learning. He was recognized for mentoring his group of 8 mentees (including three senior theses) called the PitcherPals. (Photo shows Joseph (at right) with his first senior thesis student, Jon Martin.)

The Death Cap mushroom is spreading across North America, and evolving to create new chemicals along the way. Professor Anne Pringle and colleagues are investigating why these mushrooms are now producing previously unknown natural products...

The Changing Chemistry of Invasive Death Cap Mushrooms University of Wisconsin–Madison researchers just released a groundbreaking study on the same mushrooms behind an uptick in poisonings in California.

A trip to the ER where doctors were able to quickly resolve her son's breathing emergency got Botany alumna Stacey Smith thinking about the scientific advancement that made that recovery possible and the hidden value of basic research:

The Research That Saved My Son's Life When Stacey D. Smith’s son struggled to breathe, medical practitioners skillfully and knowledgeably gave him the care he needed. In processing the scary event, Smith looked back in gratitude at all of the researchers who contributed to the creation of the medicine needed to open up his airways.

This year, Botany 300 Plant Anatomy students were given the option to write a paper or to create a video for a special assignment. The goal for the video was to be able to explain scientific concepts to the general public. One of the students, Mason Borchardt, went above and beyond with his production! Check out the video at the link:

Plant Anatomy Project Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.