Plants are not as static as you think. David Ehrhardt combines confocal microscopy with novel visualization methods to see the three-dimensional movement  within live plant cells to reveal the other-worldly cell choreography that makes up plant tissues. These methods allow his group to explore cell-signaling and cell-organizational events as they unfold.

These methods allow his lab to investigate plant cell development and structure and molecular genetics to understand the organization and dynamic behaviors of molecules and organelles. The group tackles how cells generate asymmetries and specific shapes. A current focus is how the cortical microtubule cytoskeleton— an interior scaffolding that directs construction of the cell’s walls and the growth of the plant—is organized and functions and how this guides patterns of cell growth and division. This scaffolding is crucial for supporting important plant functions such as photosynthesis, nutrient gathering, and reproduction.

Recently, his group provided surprising evidence on how this reorganization process works. The cytoskeleton undergirding in each cell includes an array of tubule-shaped protein fibers called microtubules. The evidence suggests that the direction of a light source influences a plant’s growth pattern.

Imaging data, combined with the results of genetic experiments, revealed a mechanism by which plants orient microtubule arrays. A protein called katanin drives this mechanism, which it achieves by redirecting microtubule growth in response to blue light. It does so by severing the microtubules where they intersect with each other, creating new ends that can regrow and themselves be severed, resulting in a rapid amplification of new microtubules lying in another, more desired, direction.

Ehrhardt  received his Sc. B. from Brown University and his Ph.D. from Stanford University, where he was also a postdoctoral fellow before coming to Carnegie as a staff member. For more see https://dpb.carnegiescience.edu/labs/ehrhardt-lab

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Researchers in Tübingen courtesy of Moises Exposito-Alonso.
August 28, 2019

Palo Alto, CA— Plant genetic diversity in Central Europe could collapse due to temperature extremes and drought brought on by climate change, according to a new paper in Nature led by Moises Exposito-Alonso, who joins Carnegie next month from the Max Planck Institute for Developmental Biology and UC Berkeley. Because only a few individuals of a species are already adapted to extreme climate conditions, the overall species genetic diversity could be greatly diminished, according to the findings. 

A team of researchers from the Max Planck institute, University of Tübingen, Technical University of Madrid, and UC Berkeley analyzed variants of the mustard plant

Octopus Spring in Yellowstone National Park courtesy of Devaki Bhaya
August 23, 2019

Palo Alto, CA— Carnegie plant scientists Devaki Bhaya and Arthur Grossman received a nearly $2 million grant from the U.S. National Science Foundation and the U.K. Biotechnology and Biological Sciences Research Council to study photosynthetic microbes from Yellowstone National Park’s Octopus Spring.

Together with Seppe Kuehn of the University of Illinois at Urbana-Champaign and Alison Smith and Chris Howe from the University of Cambridge, Bhaya and Grossman plan to use samples from the field to reconstruct in the lab the highly organized communities of bacteria that carpet the hot springs in a mat-like structure.

They will deploy sophisticated techniques to

Public domain image of a field of sorghum.
August 22, 2019

Palo Alto, CA— Carnegie plant biologists Sue Rhee and David Ehrhardt will lead one of 25 teams awarded a total of $64 million this week by the U.S. Department of Energy to pursue genomic research of potential biofuel crops.

“This research will help us improve crops grown for bioenergy and bioproducts while at the same time deepening our knowledge of complex and interacting biological processes within specific environmental systems,” said the agency’s Under Secretary for Science Paul Dabbar. 

Rhee and Ehrhardt, together with Carnegie geochemist George Cody, UC Berkeley’s Markita del Carpio Landry, Lawrence Berkeley National Laboratory

Winslow Briggs by Robin Kempster, courtesy Carnegie Institution for Science.
August 6, 2019

Washington, DC—The American Society of Plant Biologists (ASPB) will name a mentorship award in honor of legendary Carnegie plant scientist Winslow Briggs, who died in February. 

The ASPB is a professional society dedicated to the advancement of plant sciences.  Briggs served as its president in 1975.  He also received the society’s Stephen Hales Prize for noteworthy contributions to the field in 1994 and its Adolph E. Gude, Jr. Award for his service to the plant science community in 2007.

Briggs joined Carnegie as the Director of the Department of Plant Biology in 1973 after teaching both at Harvard University—where he completed his bachelor

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Revolutionary progress in understanding plant biology is being driven through advances in DNA sequencing technology. Carnegie plant scientists have played a key role in the sequencing and genome annotation efforts of the model plant Arabidopsis thaliana and the soil alga Chlamydomonas reinhardtii. Now that many genomes from algae to mosses and trees are publicly available, this information can be mined using bioinformatics to build models to understand gene function and ultimately for designing plants for a wide spectrum of applications.

 Carnegie researchers have pioneered a genome-wide gene association network Aranet that can assign functions

Staff Associate Kamena Kostova joined the Department of Embryology in November 2018. She studies ribosomes, the factory-like structures inside cells that produce proteins. Scientists have known about ribosome structure, function, and biogenesis for some time. But, a major unanswered question is how cells monitor the integrity of the ribosome itself. Problems with ribosomes have been associated with diseases including neurodegeneration and cancer. The Kostova lab investigates the fundamental question of how cells respond when their ribosomes break down using mass spectrometry, functional genomics methods, and CRISPR genome editing.

Kostova received a B.S. in Biology from the

Sally June Tracy applies cutting-edge experimental and analytical techniques to understand the fundamental physical behavior of materials at extreme conditions. She uses dynamic compression techniques with high-flux X-ray sources to probe the structural changes and phase transitions in materials at conditions that mimic impacts and the interiors of terrestrial and exoplanets. She is also an expert in nuclear resonant scattering and synchrotron X-ray diffraction. She uses these techniques to understand novel behavior at the electronic level.  Tracy received her Ph.D. from the California Institute of

The Ludington lab investigates complex ecological dynamics from microbial community interactions using the fruit fly  Drosophila melanogaster. The fruit fly gut carries numerous microbial species, which can be cultured in the lab. The goal is to understand the gut ecology and how it relates to host health, among other questions, by taking advantage of the fast time-scale and ease of studying the fruit fly in controlled experiments. 

Nick Konidaris is a staff scientist at the Carnegie Observatories and Instrument Lead for the SDSS-V Local Volume Mapper (LVM). He works on a broad range of new optical instrumentation projects in astronomy and remote sensing. Nick's projects range from experimental to large workhorse facilities. On the experimental side, he recently began working on a new development platform for the 40-inch Swope telescope at Carnegie's Las Campanas Observatory that will be used to explore and understand the explosive universe.

 Nick and his colleagues at the Department of Global Ecology are leveraging the work on Swope to develop a new airborne spectrograph that will be