Super-adaptable plants: the interaction between certain root proteins promotes growth in unfavorable conditions

The stress that drought generates in plants is one of the most unfavorable conditions for their growth, affecting also the geographical distribution of crops. For this reason, the study of certain root cells responsible for absorbing water and nutrients and interacting with microorganisms in the soil –called root hairs– is key to analyze the development of “super-adaptable” plants to adverse environmental conditions, especially when the effects of climate change are already strongly felt.

“We had identified that plants subjected to 10°C presented an exacerbated growth in the length of the root hairs similar to that produced by conditions with low levels of phosphate and nitrate, which drive them to find concentrations of these nutrients to allow plant development. So, we hypothesize that low temperature affects the availability and mobility of nutrients and water towards the root, which promotes hair growth,” says José Manuel Estévez, a CONICET researcher at the Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA, CONICET-Fundación Instituto Leloir).

Estévez’s team was able to determine the molecular mechanism by which the root hairs of plants become more extensive under conditions of low temperature and nutrient deficiency. “This lays the foundations for the development of super-adaptable plants, with longer hairs that allow greater absorption of nutrients in unfavorable conditions, thus promoting the development and growth of the root and of the plant in general,” says the researcher. And he explains that “one of the peculiar features of root hairs is that they can grow several hundred times their original size.”

The biologist Javier Martínez Pacheco, a CONICET fellow at the IIBBA, is the first author of the work published in New Phytologist. The study was carried out with specimens of Arabidopsis thaliana, a plant that shares biological mechanisms with the most agronomically important crops, such as corn, wheat and soybeans. Besides, laboratories from various countries, including China, Chile, Germany, France and the Czech Republic participated in the work as well as other colleagues from Argentina. This is the fourth study resulting from an international agreement signed in 2019 to strengthen scientific collaboration between the Estévez team at the Fundación Instituto Leloir and the Laboratorio Bases de Adaptación Celular led by Professor Feng Yu at the Faculty of Biological Sciences from the University of Hunan, in China.

Promising breakthrough

Different genetically modified specimens of Arabidopsis thaliana were subjected to various temperature treatments and low levels of nutrients. Through different studies (phenotyping, confocal microscopy, western blot, and immunofluorescence), the experts managed to identify three proteins with an active role in this mechanism that allows root hair growth: the FERONIA membrane receptor, the TOR kinase complex, and the protein GTPase ROP2.

“These proteins have various previously described functions, but our research provides novel information on their interrelationship in the context of root hair growth and development under cold conditions and nutrient depletion,” emphasizes Estévez.

Although in Estévez’s laboratory the team does basic research, they look for a practical application of their research that favors the development of commercial crops. “That a plant that is cultivated in the autumn or winter season has longer hairs can help a greater absorption of nutrients and water from the soil, favoring its development from early stages; and, by having a better anchorage, the root can reach a greater depth, allowing the extraction of nutrients from deeper layers of the soil”, concludes the researcher.