CRAG Postcards: messages from the microscopic world

Welcome to Postcards CRAG! If you've made it here, you've probably received one of our postcards, congratulations, we hope you like it. If you've enjoyed it so much that you want to share it with the world, you can do so using the hashtag #PostalsCRAG

A little further down, we provide you with more information about this project and about the science and authors behind the images. Find yours and enjoy the rest of the collection!

This outreach project developed by CRAG and funded by the Spanish Foundation for Science and Technology (FECYT) aims to showcase some of the research lines of our scientists through their own spectacular images. The process of taking images is fundamental in the world of science, to better understand processes, structures, reactions, etc. Some of these images, generated during the research process, are true art pieces. That's why we created this Postcards CRAG initiative, because we believe it's a good way to disseminate the knowledge and projects generated within our center, while showcasing the beauty of these investigations. Additionally, we wanted to use a more informal tone than we're used to in the scientific world because, between you and me, scientists also make omelettes, read tales, and enjoy going to the movies.

A reminder that science and art are not separate disciplines, but they nourish, inspire, and complement each other perfectly.

Potato stress 

Pedro Garcia Gagliardi and Salomé Prat

Fluorescence microscope view of a potato stem showing different components of the plant cell wall. Primary cell walls are composed of cellulose (blue). Nevertheless, other specialized cells, such as xylem cells have walls enriched with are enriched in compounds like lignin (red) and suberin (green). These specialized cells are involved in water transport and plant support.

The objective of this research was to understand how plant morphology, including vasculature, the system of specialized tissues responsible for transporting water, nutrients, and other substances throughout the plant, is affected by different stress conditions such as heat. This particular research group also focuses on the developmental changes experienced by a stolon, a specialized stem, when it becomes a tuber. 

Potato stems were sectioned into sections using an instrument to cut thin slices of material. Sections were cleaned and stained using fluorescent dyes, before observing using a fluorescent microscope. 

Inhale, exhale 

Juan B. Fontanet-Manzaneque and Ana I. Caño-Delgado

Microscopic image of plant structures, called stomata, in a leaf of an Arabidopsis thaliana plant. The stomata (blue dots spreaded all around the leaf) are pore-like structures that allow carbon dioxide to enter the plant and oxygen and water vapour to leave. Basically, it is the way how plants “breathe”. These pores are formed by two kidney-shaped cells, called the guard cells, that can open or close depending on conditions such as light, temperature, humidity, or water availability. The study of these structures is essential for understanding plant adaptation to several stresses.

The objective of this experiment was to study if stomata were closed or open and how many stomata the plant had in the case of adaptation to drought conditions. The main aim of this project is to understand how specific plant hormones influence the plant response to a certain stress like drought.

In this case, stomata cells were stained with a blue dye, to observe them using a microscope.

Cellular Galaxies 

Nerea Ruiz Solaní and Núria Sánchez Coll

In this image, we can see cells from the root of a young Arabidopsis plant, a widely used plant in scientific research. Cells usually contain a multitude of organelles and other molecules. In this case, the green structures correspond to complex of proteins, formed by proteins that were modified to emit green fluorescence for better visualization. These specific proteins are known to form condensates of various sizes. Protein condensates are structures of assembled proteins localized in a particular area of the cell and can have several functions. 

The objective of this experiment was to visualize the localization of these protein condensates within the root cells.

For the visualization of this root under the microscope, two dyes were used. The blue in the image is caused by a stain that colors the nucleus by binding to specific regions of the DNA, while the red spots constitute the portion of aggregated proteins inside a cell.

The pollen's nest

Luca Piccinini and Robertas Ursache

This image shows a microscopic view of pollen grains (big green structures) inside an anther, the masculine part of a flower from an Arabidopsis thaliana plant, which is widely used as a model in scientific research. Pollen grains have a unique cell wall composition with two distinct layers: exine and intine. Usually, the plant cell wall is not only involved in cell communication processes and shaping, but it also provides structural support and protection to the cell. In the case of pollen grain cell walls, the exine and intine layers play crucial roles in protecting the pollen grain and facilitating its function in the process of plant reproduction.

The aim of this experiment was to visualize the structure of polen in the anther and the distribution of the two distinct layers of the pollen cell walls. In particular, this project aims to study the role of certain proteins that are thought to be involved in the production of essential plant biopolymers that define cell wall architecture. 

The sample was fixed, cleared and stained to visualize biopolymers present in the cell wall.

The bodyguard 

Núria Real and Montserrat Martín

Image of a Nicotiana benthamiana (tobaco plant) cell expressing defense proteins from melon. The light purple structures are defense proteins, originally from a melon, that were expressed in tobacco for a short amount of time. These proteins mainly produced in the nucleus of the cell (big ball on the left), and also all around the plant cell. Tobacco plants are widely used to express proteins and other molecules from other plants, like melon, because it makes it easier for scientists to study them. Plants have developed defense mechanisms against pathogens, like viruses, to identify and combat the infection. In the case of viruses, identifying if a plant is infected in the fields is complicated, and it usually occurs when the infection is systemic and it is too late to save the plant.

The objective of this experiment was to study the localization of this defense protein against a virus, that is, in which areas of the cell the protein is produced. The whole project aims to understand how this protein is able to stop viral transport to the phloem, to avoid a systemic infection in the plant. 

Defense proteins were stained with a fluorescent dye before observing them using a microscope.

Thank you for your time and may science and art be with you!

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