The plant kingdom is much more sensitive and interactive than might be suspected . Dozens of studies have shown that, although they lack sensory organs like those that animals enjoy, plants are also capable of seeing, smelling, hearing, communicating with their peers and reacting to threats, especially from pathogens. Some researchers, such as the Italian botanist Stefano Mancuso, professor at the University of Florence and author of the book The Future is Vegetable , come to attribute intelligence to them, although not all his colleagues agree.
However we define it, the ability to capture reality and changes in the environment is based on protein membranes that act as sensors and that until now had not been studied in depth. An international group of scientists has just filled in that gap by drawing up a detailed map of the biochemical relationships between 200 of these proteins, published in the journal Nature .
The importance of this work should not be underestimated, since, as explained by one of its authors, Shahid Muktar, from the University of Alabama in Birmingham (United States), it will be a tool that allows the development of new methods to ” increase the resistance of plants to stress situations such as heat, drought, frost, salinity or the attack of harmful microbes “.
Experts have focused on the most important family of these sensitive proteins: the leucine-rich repeat receptor tyrosine kinase (LRR). Spread outside cell membranes, these receptor enzymes are specialized in recognizing chemical signals – such as protein fragments belonging to pathogens – and then initiating defense mechanisms inside plant cells.
Army generals
The species investigated in the laboratories – Arabidopsis thaliana – contains 600 different types of this enzyme (that is, 50 times more than humans), and they are crucial for its growth, immunity and reaction to critical situations, although little was known of its coordinated operation. The experts analyzed 400 extracellular territories where these receptors act and carried out 40,000 interaction tests between them. Then, the map thus obtained was tested with algorithms that generated various hypotheses.
All this arsenal of crossed data has demonstrated the importance of the joint work of the LRR tyrosine kinase receptors for the survival of plants and, above all, in their protection against pathogens. In the detail of the investigation, the discovery of key tyrosine kinase receptors in the coordination of the protein alert network stands out, especially one baptized by the experts as APEX. When the latter was eliminated, the plant suffered serious dysfunctions both in its development and in the immune response to microbes, although these reactions were orchestrated by enzymes far outside the sphere of influence of APEX. In other words, they would be a kind of biochemical “generals” in the war against enemies from abroad .
Reference: Elwira Smakowska-Luzan et al, An extracellular network of Arabidopsis leucine-rich repeat receptor kinases, Nature (2018). DOI: 10.1038 / nature25184
