Editor's Choice: A new test to measure treatment of plant diseases

Posted on August 9, 2018   by Laura Cox

Each month, a manuscript published in our flagship journal Microbiology is chosen by a member of the Editorial Board. This month, the paper is Comprehensive screening of antimicrobials to control phytoplasma diseases using an in vitro plant–phytoplasma co-culture system, which was selected by Dr Jennifer Cavet.


Dr Jennifer Cavet: Phytoplasmas infect over a thousand different plant species and cause devastating crop losses worldwide. Strategies to control these non-culturable plant-pathogenic bacteria have been hampered by the lack of an efficient antimicrobial screening system. This article describes the development of an efficient in vitro plant-phytoplasma co-culture system which allows for the accurate screening of antimicrobial efficacy. The authors put this system to use and tested a range of antimicrobials and approaches to control phytoplasmas. As a result, they were able to successfully eliminate phytoplasma from infected plants. This article thus makes an important step forward in the development of phytoplasma disease control strategies, with the applicability of the system also likely to extend to the study and management of other important non-culturable bacterial crop diseases.

Comprehensive screening of antimicrobials to control phytoplasma diseases using an in vitro plant–phytoplasma co-culture system

Phytoplasmas are plant pathogens. These bacteria are transferred by insects which feed on phloem; the plant tissue which transports sugars from the leaves of the plant to the stem and roots.

Phytoplasmas cannot be grown in the lab on media, making them very difficult to study. The authors of this research article have developed a new, reproducible technique to assess which antimicrobials are most effective against phytoplasmas in vitro.

The new technique involves taking cuttings from a garland chrysanthemum which is infected with phytoplasma and growing them in antimicrobial medium for four weeks. After these cuttings have been growing with the antimicrobial-infused medium, they are tested for symptoms of phytoplasma infection and accumulation of phytoplasma.

After developing the test, they then used it to assess the effectiveness of a number of potential anti-phytoplasma antimicrobials. They found tetracycline and rifampicin to be the most effective, both of which eliminated phytoplasma completely in the cuttings.

The authors hope that this test will be useful in phytoplasma control, and contribute to the understanding of mechanisms of antimicrobial resistance in phytoplasma populations.

To access the full paper, click here. Papers published in Microbiology are available to journal subscribers, but the abstracts are free to read. Articles can also be purchased individually with the pay-per-view option.