Plant immunity

Issue #32; Winter 2019-2020

Just like us, plants must survive against pathogen threats, while recognising beneficial microbes.

Unlike us, plants lack a centralised immune system with special cells to fight disease. In plants, every cell must defend itself. Here are some of the microorganisms which plants must recognise alongside a simplified model of the current understanding of plant immunity.


Bacteria are microscopic, single-celled organisms. Similar bacteria can have both good and bad interactions with plants.

Dr Jacob Malone and his group investigates pathogenic and beneficial soil-dwelling bacterial Pseudomonas strains.


A virus is another type of microscopic organism, which replicates only inside living cells. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea.

Professor George Lomonossoff’s group revealed structural details of the Luteoviridae plant viruses that infect a wide range of food crops.


Despite being responsible for one of the most well-known plant diseases, potato late blight, oomycetes are the least well-known of the organisms that cause plant disease. These organisms look like, and are commonly mistaken for, fungi.

The Kamoun lab, based at The Sainsbury Laboratory, has a long history of genomics-led research on oomycetes.


Like bacteria fungi can be a pathogen or symbiont for a plant. Pathogenic fungi are responsible for a variety of devastating plant diseases.

Dr Diane Saunders studies wheat rust pathogens. Recently her team with international collaborators (CIMMYT and Ethiopian Institute of Agricultural Research) developed a portable platform for diagnosing individual strains of yellow rust as they evolve in the field. This new technology is known as Mobile And Real-time PLant disEase (MARPLE) diagnostics.


Insects have a large impact on plant health. Last year, many brassica crops such as oilseed rape were devastated by the cabbage stem flea beetle.

Professor Steven Penfield’s group are looking to identify innate resistance to this pest. Insects can act as a carrier, called a vector, for pathogens. The BRIGIT program, led by Professor Saskia Hogenhout, which is investigating the spread of plant disease, and how insects act as vectors.

More Articles

  • Xylella: a bacterial threat

    Issue #32; Winter 2019-2020

    New and emerging pathogens threaten crop production, forestry, commercial horticulture, as well as woodlands and broader biodiversity. Both environmental change, increased movement and trade of plants and plant materials around the globe further increase the risks of a plant pathogen spreading

    Read the article
  • Awards & achievements

    Issue #32; Winter 2019-2020

    Scientists at the John Innes Centre are recognised for their contributions to the research community, both nationally and internationally

    Read the article
  • Rising from the ashes

    Issue #32; Winter 2019-2020

    For the past decade, the future has looked bleak for European ash trees. However the evidence emerging in Norfolk’s woodlands, combined with the latest scientific research suggests a brighter outlook

    Read the article