| Agriculture

Technology uses electric fields to protect crops against pathogens

Spores of "Phytophthora palmivora" exhibit electrotactic behavior, that is, they are naturally attracted to positive electrical charges

25.10.2024 | 15:51 (UTC -3)

Cultivar Magazine

Schematic of the 3D printed V-box setup for root infection assays with P. palmivora zoospores in the presence of external electric fields. The negative and positive electrodes are connected to an external power supply. (A) Global electric field setup. The roots are enveloped in a constant ionic current. (B) Local electric field setup. The electrodes are mounted on a simulated root located on one side of the V-box, so that the roots are not enveloped in the ionic current. (C) Simulated root used to generate the local electric field, with slots used to insert the positive and negative electrodes — Schematic of the 3D printed V-box setup for root infection assays with P. palmivora zoospores in the presence of external electric fields. The negative and positive electrodes are connected to an external power supply. **(A)** Configuration of the global electric field. The roots are enveloped in a constant ionic current. **(B)** Local electric field setup. The electrodes are mounted on a dummy root located on one side of the V-box, so that the roots are not involved in the ionic current. **(C)** Simulated root used to generate the local electric field, with slots used to insert the positive and negative electrodes

Scientists have developed an approach to protect plants against pathogen attacks using weak electric fields. The research reveals that applying electric fields close to plant roots can significantly reduce the adhesion of harmful spores, offering a sustainable alternative to traditional pest control methods.

The study demonstrated that spores of Phytophthora palmivora exhibit electrotactic behavior, that is, they are naturally attracted to positive electrical charges. By positioning electric field generating devices close to the roots of plants such as Arabidopsis thaliana e Medicago truncatula, the team managed to considerably reduce the number of spores attached to the roots, without compromising the health of the plants.

The research indicated that electric fields not only decreased spore adhesion but also inhibited mycelial growth of the pathogen on plant roots after 24 hours of exposure. This suggests that the application of ionic currents can interrupt multiple steps in the infection process of P. palmivora in hydroponic systems.

The methodology adopted involved two configurations of electric field application: a global one, which involves the plant roots with ionic currents, and a local one, where the currents are induced at a distance from the roots. Both configurations showed effectiveness in reducing spore adhesion, although the global configuration demonstrated greater efficiency in Arabidopsis. In Medicago truncatula, both configurations had a similar impact, possibly due to the stronger response of spores to chemical rather than electrical gradients.

The researchers suggest that this approach could be especially useful for large-scale crops such as cocoa, papaya and açaí, where the placement of "dummy roots" that generate electric fields could effectively protect the plants.

It is important to highlight that the applied electric fields did not negatively affect the growth or general health of the plants, with only a slight reduction in the growth of the primary roots of Arabidopsis, without compromising its gravitropy.

The researchers emphasized that "by studying the bioelectric component of host-pathogen interactions at fundamental levels, we have the opportunity to develop new approaches to crop protection." This strategy can be used in conjunction with other agricultural practices, minimizing pathogen load and contributing to agricultural sustainability and productivity.

More information can be found at doi.org/10.1038/s41598-024-68730-y