Scientists uncover an elusive plant pathogen in Mexico

For years, scientists and online databases suspected the occurrence of clubroot — one of the major diseases affecting cruciferous vegetables (like broccoli, cabbage, and kale) — in Mexico. However, there was no evidence to support this suspicion until a team of researchers led by Mauricio Luna and Legnara Padrón-Rodríguez of the University of Veracruz donned their detective hats to locate the clubroot pathogen.

Because Mexico is the fifth-largest producer of broccoli in the world and a primary supplier to the eastern United States and Canada, determining the presence of the pathogen is important to prepare for possible outbreaks. Legnara Padrón developed the detection method during COVID-19, prompting the authors to consider what might happen if a future pandemic affects plants. The method involved working with cruciferous growers in Mexico and collecting soil samples from three categories of fields: fields in production, fields without cruciferous vegetables for up to one year, and fields that had stopped growing cruciferous vegetables. They were able to extract the clubroot pathogen after growing a number of cruciferous vegetables in the collected soil. Typical clubroot symptoms appeared on the roots of infected plants, the results of which were confirmed using molecular methods.

Now researchers can examine whether the clubroot pathogen has been suspected to have stunted the growth of cruciferous vegetables in certain Mexican fields. New fields affected by the disease have been added to ClubrootTracker, an online tool developed by Dr. Pérez-López was developed to detect the Clubroot pathogen. In addition, their findings will greatly improve future Clubroot management and secure the cruciferous vegetable economy in Mexico and the world’s supply of this important vegetable.

Corresponding author Edel Pérez-López comments that their “findings open the door to more exciting research, such as studying the genome of Mexican isolates of P. brassicae, their geographic distribution and their evolution compared to other North American isolates.” The strategy we are pursuing could help discover the clubroot pathogen in other geographic areas, or possibly other soil-borne pathogens.”

This study embodies the importance of listening to growers. Their knowledge, combined with science, can provide answers that improve crop disease management and increase farm revenues.

The study was published in plant disease.

Provided by the American Phytopathological Society