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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Margaret McFall-Ngai
November 17, 2021

Washington, DC—Pioneering microbiome specialist Margaret McFall-Ngai has been named the inaugural director of Carnegie’s newly launched research division focused on life and environmental sciences, which will deploy an integrated, molecular-to-global approach to tackling the challenges of sustainability, resilience, and adaptation to a changing climate. McFall-Ngai will join the institution in January, 2022, from the University of Hawai‘i at Mānoa, where she is a professor at the Pacific Biosciences Research Center’s Kewalo Marine Laboratory and the center’s director emerita.

“Margaret’s exemplary research and groundbreaking vision are the

Rose rust on plant leaves. Image purchased from Shutterstock.
October 26, 2021

Palo Alto, CA—New work led by Carnegie’s Kangmei Zhao and Sue Rhee reveals a new mechanism by which plants are able to rapidly activate defenses against bacterial infections. This understanding could inspire efforts to improve crop yields and combat global hunger.

“Understanding how plants respond to stressful environments is critical for developing strategies to protect important food and biofuel crops from a changing climate,” Rhee explained. 

Published in eLife, new work from Zhao and Rhee, along with Carnegie’s Benjamin Jin and Stanford University’s Deze Kong and Christina Smolke, investigated how production of a plant defense

October 4, 2021

Palo Alto, CA—Carnegie’s Devaki Bhaya is part of a Rice University led team that was recently awarded $2.8 million from the National Science Foundation for a five-year project to define the social order of naturally occurring microbial communities.

Unlike the bacterial clones used in laboratory research, naturally occurring bacterial populations are havens of small-scale genetic diversity, making their relationships and evolutionary dynamics of great interest to the scientific community.

“From extremophiles living in deep sea vents to the beneficial bacteria living in the human gut or in association with plant roots, microbial communities are crucial to

September 24, 2021

Palo Alto, CA—Former Carnegie Staff Associate Martin Jonikas, now an Associate Professor of Molecular Biology at Princeton University, was named one of 33 new Howard Hughes Medical Institute (HHMI) Investigators. HHMI recognized Jonikas for his research on photosynthetic algae, which could revolutionize agriculture and biofuels by making crop plants better at converting carbon dioxide from the atmosphere into usable energy sources such as sugars.

Each member of the cohort will receive roughly $9 million over a seven-year term. They were selected for “diving deep into tough questions that span the landscape of biology and medicine.”

Photosynthesis is

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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