A team of scientists identifed how plants react to invading pathogens
using their own mobile disease detectors. The discovery can lead to the
selection of plants with more natural resistance and breeding of more
disease-resilient crop varieties.

The scientists from the Imperial College of London recently published
their paper where they described how they were able to investigate the
plant's reactions to an invading pathogen which provided them evidence
about how a plant's immune sensors work. Immune sensors are found in
plant cells and detect the presence of specific proteins called
effectors, which infectious microbes use to facilitate infection.

The scientists were able to identify the first-known mobile immune
sensor that is able to navigate to where a microbe is invading using
the/Phytophtora infestans/, a microbe that causes the potato blight
disease. They created a variant of the immune sensor that did not
immediately result in cell death, which is what normally happens to
invading microbes once detected by the plant immune sensor. By delaying
the cell death, the scientists observed the intact preceding parts of
the immune response by attaching fluorescent markers in the immune
sensors and observing them under a powerful microscope. They saw that
when the/P. infestans/began to invade, they form specialized infection
structures by creating extensions of themselves in the plant cell. They
described that around the extensions were extrahaustorial membrane
created by the plant cell, then a specific immune sensor gathered around
the membrane. What is interesting is that the scientists noted that this
specific immune sensor traveled to the location from a different part of
the cell, providing evidence that they are not static to one part of the
plant cell and can move to parts where infection occurs. Further
observation showed that the immune sensors changed their organization
and formed bright spots called resistosomes spread out to the cell
periphery. Resistomes gather on the plant cell's plasma and kills plant
cells in order to starve and eliminate the invading microbe.

By identifying this plant response, researchers can move their studies
forward to breed crops with the better disease-resilience and possibly
improved immune sensors in genetically modified plants.

Dynamic localization of a helper NLR at the plantā??pathogen interface
underpins pathogen recognition | PNAS
[www.pnas.org]