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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Pennycress
August 3, 2020

Palo Alto, CA— Carnegie’s Sue Rhee and Moises Exposito-Alonso are leading members of an initiative to identify genes related to stress tolerance in the mustard plant field pennycress. Theirs was one of seven biofuel research projects awarded a total of $68 million over five years by the Department of Energy. 

Climate change is one of the greatest challenges facing humankind and scientists from a wide variety of fields are applying their expertise to help understand and mitigate its effects. This includes plant scientists, whose work can help maintain food security in a warming climate, sequester carbon pollution from the atmosphere, and develop renewable energy

Moises Exposito-Alonso
July 14, 2020

Palo Alto, CA— Carnegie evolutionary geneticist Moises Exposito-Alonso was awarded a Max Planck Society’s Otto Hahn Medal for early career excellence. The prize is endowed with 7,500 euros.

Since 1978, the society has recognized outstanding scientific achievements among its recent Ph.D. recipients with the goal of motivating particularly talented individuals to pursue academic research careers. The 2020 award was given to six scientists in the biological and medical fields; 10 in human sciences; and 10 in the chemistry, physics, and technology sector. The recipients are nominated by the directors of the Max Planck Institutes at which they conducted their doctoral

Greenhouse in Germany where Exposito-Alonso did research.
April 10, 2020

Palo Alto, CA— Carnegie’s Moises Exposito-Alonso was selected for the Heidelberg Academy of Science’s Karl Freudenberg Prize in recognition of outstanding early career achievements in the natural sciences. The prize comes with a personal 10,000 Euro award.

Representing the German state of Baden-Württemberg, the academy honors several professors under the age of 40 with endowed prizes each year, including six in 2020. All of the recipients will give public presentations of their work, with dates to be announced. An evolutionary geneticist, Exposito-Alonso received his doctorate in 2018 from the Max Planck Institute for Developmental Biology in Tübigen.

Moises Exposito-Alonso
March 18, 2020

Washington, DC— Carnegie evolutionary geneticist Moises Exposito-Alonso was named a member of the 2020 class of Forbes’ 30 Under 30 Europe list in science and healthcare. 

He was recognized for his lab’s pioneering use of genomic techniques to understand how plant species will evolve and keep pace with a changing climate. 

Out of the thousands of nominees, the 30 finalists in each of the 10 categories comprise “the world’s most impactful community of young entrepreneurs and game-changers,” said the publication in announcing his selection.  

“Growing up in southern Spain, I saw how Mediterranean

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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

Brittany Belin joined the Department of Embryology staff in August 2020. Her Ph.D. research involved developing new tools for in vivo imaging of actin in cell nuclei. Actin is a major structural element in eukaryotic cells—cells with a nucleus and organelles —forming contractile polymers that drive muscle contraction, the migration of immune cells to  infection sites, and the movement of signals from one part of a cell to another. Using the tools developed in her Ph.D., Belin discovered a new role for actin in aiding the repair of DNA breaks in human cells caused by carcinogens, UV light, and other mutagens.

Belin changed course for her postdoctoral work, in

Evolutionary geneticist Moises Exposito-Alonso joined the Department of Plant Biology as a staff associate in September 2019. He investigates whether and how plants will evolve to keep pace with climate change by conducting large-scale ecological and genome sequencing experiments. He also develops computational methods to derive fundamental principles of evolution, such as how fast natural populations acquire new mutations and how past climates shaped continental-scale biodiversity patterns. His goal is to use these first principles and computational approaches to forecast evolutionary outcomes of populations under climate change to anticipate potential future

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