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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April 9, 2018

Palo Alto, CA—Senior scientist Arthur Grossman of Carnegie’s Department of Plant Biology was part of a team* awarded a three-year grant, with $100,000 for each year, from the International Human Frontier Science Program (HFSP) Organization. The team will use an integrated approach to investigate how light and metabolic signals control photosynthetic processes in algae.  

HFSP’s collaborative research grants are given for endeavors that address “complex mechanisms of living organisms.” The program only supports “cutting-edge, risky projects” conducted by globally distributed teams.

Grossman has been studying algae for years.  Algae dominate the oceans, produce half of the

February 16, 2018

Stanford, CA—Roots face many challenges in the soil in order to supply the plant with the necessary water and nutrients.  New work from Carnegie and Stanford University’s José Dinneny shows that one of these challenges, salinity, can cause root cells to explode if the risk is not properly sensed. The findings, published by Current Biology, could help scientists improve agricultural productivity in saline soils, which occur across the globe and reduce crop yields.

Salts build up in soils from natural causes, such as sea spray, or can be introduced as a consequence of irrigation and poor land management. Salinity has deleterious effects on plant health and limits crop yields,

Carnegie Science, Carnegie Institution, Carnegie Institution for Science, Stanford University
January 9, 2018

Washington, DC— Without eyes, ears, or a central nervous system, plants can perceive the direction of environmental cues and respond to ensure their survival.

For example, roots need to extend through the maze of nooks and crannies in the soil toward sources of water and nutrients. The various ways that plants guide this branching to take advantage of their environment is of great interest to scientists and of potential use by farmers in need of crops that produce more food with fewer resources.

Carnegie and Stanford University biologist José Dinneny has spent years studying how root growth responds to water, particularly through a phenomenon called hydropatterning, which

October 4, 2017

Science News magazine has selected José Dinneny, of Carnegie’s Department of Plant Biology, as one of ten young scientists to watch in 2017. The researchers were selected because they are likely to make big discoveries. The investigators are spotlighted in the October 14 edition of Science News available online today at www.sciencenews.org/SN10.

Dinneny looks at the mechanisms plants use to sense water availability and survive stressful conditions such as drought and high salinity. He investigates developmental pathways and molecular genetic mechanisms involved in shaping the plant to suit the environment. His work has included the processes of water-stress responses in plants at

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Carnegie will receive Phase II funding through Grand Challenges Explorations, an initiative created by the Bill & Melinda Gates Foundation that enables individuals worldwide to test bold ideas to address persistent health and development challenges. Department of Plant Biology Director Wolf Frommer,  with a team of researchers from the International Rice Research Institute, Kansas State University, and Iowa State University, will continue to pursue an innovative global health research project, titled “Transformative Strategy for Controlling Rice Blight.”

Rice bacterial blight is one of the major challenges to food security, and this project aims to achieve broad, durable

Carnegie researchers recently constructed genetically encoded FRET sensors for a variety of important molecules such as glucose and glutamate. The centerpiece of these sensors is a recognition element derived from the superfamily of bacterial binding protiens called periplasmic binding protein (PBPs), proteins that are primary receptors for moving chemicals  for hundreds of different small molecules. PBPs are ideally suited for sensor construction. The scientists fusie individual PBPs with a pair of variants and produced a large set of sensors, e.g. for sugars like maltose, ribose and glucose or for the neurotransmitter glutamate. These sensors have been adopted for measurement of sugar

Fresh water constitutes less than 1% of the surface water on earth, yet the importance of this simple molecule to all life forms is immeasurable. Water represents the most vital reagent for chemical reactions occurring in a cell. In plants, water provides the structural support necessary for plant growth. It acts as the carrier for nutrients absorbed from the soil and transported to the shoot. It also provides the chemical components necessary to generate sugar and biomass from light and carbon dioxide during photosynthesis. While the importance of water to plants is clear, an understanding as to how plants perceive water is limited. Most studies have focused on environmental conditions

Today, humanity is increasingly aware of the impact it has on the environment and the difficulties caused when the environment impacts our communities. Environmental change can be particularly harsh when the plants we use for food, fuel, feed and fiber are affected by this change. High salinity is an agricultural contaminant of increasing significance. Not only does this limit the land available for use in agriculture, but in land that has been used for generations, the combination of irrigation and evaporation gradually leads to increasing soil salinity.

The Dinneny lab focuses on understanding how developmental processes such as cell-type specification regulate responses to

Staff member Nick Konidaris joined Carnegie in October 2017. He works on a variety of new optical instrumentation projects in astronomy. He  recently began working on a new development platform for the 40-inch Swope telescope at Carnegie's Las Campanas Observatory. It is called the Rapid Response Swope Spectrograph and Imager (R2S2I). When operational, it will be a workhorse instrument and development platform.

Prior to Carnegie, he was director of product management at Kairos Aerospace in Mountain View, CA. Konidaris received a B.S. in physics from Carnegie Mellon University, and conducted coursework in electrical engineering before obtaining a Ph.D. in astrophysics from the

Experimental petrologist Michael Walter became director of the Geophysical Laboratory beginning April 1, 2018. His recent research has focused on the period early in Earth’s history, shortly after the planet accreted from the cloud of gas and dust surrounding our young Sun, when the mantle and the core first separated into distinct layers. Current topics of investigation also include the structure and properties of various compounds under the extreme pressures and temperatures found deep inside the planet, and information about the pressure, temperature, and chemical conditions of the mantle that can be gleaned from mineral impurities preserved inside diamonds.

Walter had been at

Guoyin Shen's research interests lie in the quest to establish and to examine models for explaining and controlling the behavior of materials under extreme conditions. His research activities include investigation of phase transformations and melting lines in molecular solids, oxides and metals; polyamorphism in liquids and amorphous materials; new states of matter and their emergent properties under extreme conditions; and the development of enabling high-pressure synchrotron techniques for advancing compression science. 

He obtained a Ph.D. in mineral physics from Uppsala University, Sweden in 1994 and a B.S. in geochemistry from Zhejiang University, China in 1982. For more

Leopoldo Infante became the director of the Las Campanas Observatory on July 31, 2017.

Since 2009, Infante has been the founder and director of the Centre for Astro-Engineering at the Chilean university. He joined PUC as an assistant professor in 1990 and has been a full professor since 2006. He was one of the creators of PUC’s Department of Astronomy and Astrophysics, and served as its director from 2000 to 2006. He also established the Chilean Astronomical Society (SOCHIAS) and served as its president from 2009 to 2010.

Infante received his B.Sc. in physics at PUC. He then acquired a MSc. and Ph.D. in physics and astronomy from the University of Victoria in Canada.