Protection against diseases caused by surface-staining fungi: a compound consisting of active peptides and soluble silicon

Phytopathogenic fungi rank among the most common causes of diseases in economically important plant crops worldwide. They not only damage the crops-fungal diseases also weaken the plant’s ability to resist biotic or abiotic stress factors. The new approaches to plant protection against fungal disease have aroused interest because of environmental concerns and norms restricting use of pesticides.

The fungi that belong to the Ascomycota group are among the most common surface-staining fungi, the most dangerous being the powdery mildew fungi (Erysiphe, Microsphaera, Podosphaera, Uncinula, among other genera). Moreover, other well known diseases such as peach leaf curl (Taphrina), rice blast (Magnaporthe), Black sigatoka in banana (Mycosphaerella) or a number of Basidiomycota fungi such as rust (Puccinia, Uromyces, etc.) are also caused by these types of fungi that attack the plant tissue through the foliar surfaces.
Due to the infection mechanism used by these fungi (through the cuticle) the thickness and resistance of the cuticle is the most important physical barrier that fungi spores must overcome to infect the subjacent tissue. In this regard, it has been noticed that the absorption and subsequent deposition of silicon (Si) under the cuticle is crucial to confer greater resistance to tissues against fungal attack, and that these species and varieties with predisposition to accumulate silicon are usually more resilient to these diseases. Moreover, although silicon is the second most common element on the Earth’ surface, it has limited solubility and cannot be easily assimilated by plants. Therefore, most of it is not found in a bioavailable form. Providing plants with soluble, easy to assimilate silicon could greatly enhance crop survivability and productivity.
On the other hand, there are certain peptides that strengthen the plant’s natural defenses against fungal infection. These peptides activate and reinforce the metabolic signal paths associated to cell signaling and synthetisation of antimicrobial compounds (increase in the activity of the PAL enzyme, accumulation of callose and lignin polymers). These biological mechanisms help to reduce the chances of fungal infection when weather conditions might favor it.
Therefore, for crops susceptible to fungal diseases, a treatment using soluble silicon and peptidic compounds that favor its absorption and stimulate the plant’s natural defenses is an integrated, environmentally friendly strategy that guarantees better security and protection for our crops.
Keeping that strategy in mind, Bioiberica’s R&D Department developed Armurox®, a foliar or root product composed of a soluble silicon peptide active compound. Its ability to improve resilience and control fungal disease has been demonstrated in field trials in a number of Mediterranean and Subtropical crops. The results of some of these field trials can be found in our website.