Internal Seminar. Rubén Rellán Álvarez, Dinneny Lab, The ground truth: understanding root physiology in soil using a novel imaging platform. Heather Cartwright, Briggs Lab, New and Upcoming Additions to the Imaging Facility

Event Dates: May 23, 2014 - 4:00pm - 5:00pm

Rubén Rellán Álvarez - Abstract

Rubén Rellán Álvarez, Pierre-Luc Pradier, Muh-Ching Yee, Emilie Winfield, Geng Yu and José R. Dinneny

Roots anchor plants to the soil, are the entry point for nutrients and water uptake, exude a diverse array of compounds that allow associations with microorganisms and other plants, they integrate the information that is gather from the heterogenous nature of the soil and ultimately modulate all the above process to ensure proper plant growth. The basic understanding of root physiology is key to develop agricultural strategies and plant varieties that enable us to grow plants in poor soils, using less external inputs and produce more nutritious crops with better yields.

Roots are buried deep in the soil and difficult to sample or image without altering their basic structure and physiology. In order to visualize and understand root biology, researchers often make compromises and study roots in growth environments that remove roots from their natural habitat. In an effort to understand root biological processes in conditions that match more closely the physiological conditions that occur in soil, we have developed a new growth and imaging system that enables the simultaneous observation of root growth, root system architecture (RSA) and gene expression patterns of roots of Arabidopsis plants growing in soil, in a transpiring environment and for extended periods of time. The system is based on the use of bioluminescent reporters emitting at different wavelengths of light. We use single color transgenic plants constitutively expressing a luciferase reporter to mark RSA and double transgenic plants co-expressing another -different- luciferase reporter to mark gene expression. We grow the luciferase expressing plants in plastic vessels (rhizotrons) filled with soil and then visualize them using a custom imaging system.

The system is allowing us to ask questions about root processes that were very difficult to tackle with current technology such as the root response to light and drought or the interaction between roots from different plants. I will present our latest data on the above subjects and also comment on our future plans and improvements of the system.

Heather Cartwright - Abstract

I will introduce two new systems (being) made right here at Carnegie:

Vertical imaging system
Built from scavenged parts and running in open-source Micro-Manager, the vertical imager can be used for timelapse imaging and/ or fluorescence screening of seedlings growing on plates.

Also called Light Sheet Microscopy, Selective Plane Illumination Microscopy (SPIM) uses a sheet of laser to illuminate a thin section of the specimen. Fluorescence from the excited section is collected through an objective positioned 90º to the light sheet, then detected by a fast and sensitive sCMOS camera. Each image is captured in just a few milliseconds, so we can collect a 3D image stack of an entire Arabidopsis root in a matter of seconds. There is no out-of-focus excitation, so SPIM causes less photodamage than point-scanning or spinning disk confocal microscopy.

I will show images from demos of the Zeiss LightSheet and discuss the Open SPIM-based system we are building here.