Chickpeas have rabies, can they be vaccinated?

Like animals, plants are affected by diseases caused by microorganisms (viruses, bacteria, fungi, etc.). There are pathogens that specialize in “damaging” plant tissue, and at the same time they are harmless to humans.

An example, although it may seem difficult, is rabies affecting chickpea plants, which has nothing to do with the viral disease affecting animals.

Chickpeas with scientific name Citzer arietinumis the second most produced legume crop in the world (>18 million tons) after beans.

At a nutritional level, it is an important source of digestible protein (23-28% by weight) and fiber (18-22% by weight), as well as beneficial fatty acids (oleic and linoleic), minerals (calcium, magnesium, phosphorus and potassium) and vitamins (A and Bs). Thus, it represents a very important crop throughout the world, both economically and for the nutrition of many population groups.

Among the wide variety of chickpeas available on the market, protected geographical indication (PGI) chickpeas stand out for their exceptional quality. An example is Garbanzo de Fuentesauco PGI, produced in the southeast of the province of Zamora (Castile and Leon, Spain).

Although it is not a very productive legume, it has exceptional culinary qualities, recognized throughout the world for its large size, texture and taste.

Angry Beans

Now that the “victim” has been introduced, let’s talk about his “killer.” If we talk about rabies, then everyone will think that we are talking about this terrible viral disease that affects the brain of animals, causes aggressive behavior (for example, biting) and ends in the death of the sick person.

However, the animal virus does not infect plants, so we are talking about a completely different disease. Askohita rabiei (or Didimella rabiei) is the scientific name of the fungus that causes chickpea rabies, a very aggressive disease widespread throughout the world.

The spores of this fungus are carried by wind or rain until they settle on the surface of the plant. There they germinate and the fungus penetrates the host tissue, causing black, circular necrotic lesions (dead tissue), primarily on leaves and stems.

With a very aggressive attack, the plant defoliates (leaves fall off) and dies from suffocation. Moreover, if the plant produces seeds, the pathogenic fungus colonizes them, passing the disease to the next generation.

Currently, it is very difficult to control this infection due to the lack of resistance in chickpeas and the ineffectiveness of chemical fungicides. Therefore, biological control strategies may be a solution to the problem.

Mushrooms that will protect invaders

One of the biological control agents successfully used against various agricultural diseases is Trichodermaa genus of very useful filamentous mushrooms.

They colonize plant roots and help them fight pathogens, for example by “eating” them directly, producing antimicrobial compounds (antibiotics and antifungals), or competing for space and nutrients present in the soil.

In addition, by colonizing plant roots, Trichoderma It is recognizable by its “domesticity,” which activates the plant’s defenses in all its tissues. Thus, it acts as a “plant vaccine”.

Knowledge of the disease affecting this crop and the opportunities it presents. TrichodermaA research group from the University of Valladolid Agrobiotech, together with researchers from the Biological Mission of Galicia (CSIC), developed a work in which chickpea plants from Fuentesauco (IGP) were “vaccinated”.

In this study, which was just published in a scientific journal Biological controldifferent types Trichoderma determine which of them is capable of activating the defenses of chickpea plants and suppressing the growth of the pathogen.

After various experiments the species was identified. Trichoderma harcianum as the most effective. Subsequently, the chickpea seeds were enveloped in the spores of this beneficial fungus, covering them with gum arabic.

Seeds were sown in pots of soil collected from crop fields in Fuentesauco where the pathogen was known to be present. When the plants grew, they were artificially infected with the pathogen.

In this way it was possible to demonstrate how Trichoderma harcianum acts as a “vaccine” against rabies caused by chickpeas. Finally, thanks to the methods of hormonomics and metabolomics, it has been revealed how this new ally works when it comes to protecting plants from infection.

At the current stage, field trials are being carried out with PGI farmers of Fuentesauco-Garbanzo to determine the true effectiveness of this biotechnological tool in real crop growing conditions.

Effective disease control will mean significant improvements in this agricultural practice applicable to chickpea crops worldwide.