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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Artwork is courtesy of Mark Belan | artscistudios.com.
September 22, 2022

Palo Alto, CA—Climate change and habitat destruction may have already caused the loss of more than one-tenth of the world’s terrestrial genetic diversity, according to new research led by Carnegie’s Moises Exposito-Alonso and published in Science. This means that it may already be too late to meet the United Nations’ proposed target, announced last year, of protecting 90 percent of genetic diversity for every species by 2030, and that we have to act fast to prevent further losses.

Several hundred species of animals and plants have gone extinct in the industrialized age and human activity has impacted or shrunk half of Earth’s ecosystems, affecting

Tidestromia oblongifolia in winter, Death Valley National Park, CA, USA, Photo b
August 23, 2022

Palo Alto, CA— Water is inextricably linked to our understanding of life—it makes up most of our planet’s surface and organisms across the tree of life depend on it to function. Yet the ability to survive extremely dry conditions for long periods is crucial to the life cycles of many species—including in plants, which can reproduce from desiccated pollen grains and grow from dried-out seeds.

“There are some desert plants and micro-animals, like tardigrades, which can lose up to 90 percent of their water and resume normal biological function within hours of being rehydrated. We want to know how they do it,” said Carnegie’s Sue Rhee, who was

Stephanie Hampton
August 12, 2022

Washington, DC— Aquatic ecologist Stephanie Hampton joined Carnegie as Deputy Director of Carnegie’s newly launched Division of Biosphere Sciences and Engineering at the end of July. She arrived from the National Science Foundation, where she was the director of the Division of Environmental Biology. She was also a professor and the former director of an interdisciplinary environmental research center at Washington State University.

“Stephanie’s experience leading the primary funder of basic ecological and evolutionary research in the U.S. has given her a 10-thousand-foot view of the field, which will help us as we implement a new, cross-disciplinary vision

Illustration of a plant growing on a computer chip purchased from Shutterstock.
June 13, 2022

Palo Alto, CA— New work led by Carnegie’s Zhiyong Wang untangles a complex cellular signaling process that’s underpins plants’ ability to balance expending energy on growth and defending themselves from pathogens. These findings, published in Nature Plants, show how plants use complex cellular circuits to process information and respond to threats and environmental conditions.  

“Plants don’t have brains like us, and they may be fixed in place and unable to flee from predators or pathogens, but don’t feel sorry for them, because they’ve evolved an incredible network of information-processing circuits that enable them to ‘

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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

Ana Bonaca is Staff Member at Carnegie Observatories. Her specialty is stellar dynamics and her research aims to uncover the structure and evolution of our galaxy, the Milky Way, especially the dark matter halo that surrounds it. In her research, she uses space- and ground-based telescopes to measure the motions of stars, and constructs numerical experiments to discover how dark matter affected them.

She arrived in September 2021 from Harvard University where she held a prestigious Institute for Theory and Computation Fellowship. 

Bonaca studies how the uneven pull of our galaxy’s gravity affects objects called globular clusters—spheres made up of a million

Peter Gao's research interests include planetary atmospheres; exoplanet characterization; planet formation and evolution; atmosphere-surface-interior interactions; astrobiology; habitability; biosignatures; numerical modeling.

His arrival in September 2021 continued Carnegie's longstanding tradition excellence in exoplanet discovery and research, which is crucial as the field prepares for an onslaught of new data about exoplanetary atmospheres when the next generation of telescopes come online.

Gao has been a part of several exploratory teams that investigated sulfuric acid clouds on Venus, methane on Mars, and the atmospheric hazes of Pluto. He also

Anne Pommier's research is dedicated to understanding how terrestrial planets work, especially the role of silicate and metallic melts in planetary interiors, from the scale of volcanic magma reservoirs to core-scale and planetary-scale processes.

She joined Carnegie in July 2021 from U.C. San Diego’s Scripps Institution of Oceanography, where she investigated the evolution and structure of planetary interiors, including our own Earth and its Moon, as well as Mars, Mercury, and the moon Ganymede.

Pommier’s experimental petrology and mineral physics work are an excellent addition to Carnegie’s longstanding leadership in lab-based mimicry of the

Johanna Teske became the first new staff member to join Carnegie’s newly named Earth and Planets Laboratory (EPL) in Washington, D.C., on September 1, 2020. She has been a NASA Hubble Fellow at the Carnegie Observatories in Pasadena, CA, since 2018. From 2014 to 2017 she was the Carnegie Origins Postdoctoral Fellow—a joint position between Carnegie’s Department of Terrestrial Magnetism (now part of EPL) and the Carnegie Observatories.

Teske is interested in the diversity in exoplanet compositions and the origins of that diversity. She uses observations to estimate exoplanet interior and atmospheric compositions, and the chemical environments of their formation