How plants close the door to pathogens
The closure of stomata – pores in plant leaves – to prevent infection by pathogens is a bit like the fire doors of a building closing automatically when a smoke detector is activated.
However, not all of the links between the detector and the closure mechanism are known.
Working with colleagues from different international laboratories, we have now identified one of the key missing links in the chain.
Stomata are composed of two guard cells that form two sides of a ring-like shape. These cells can expand or contract, leading to closure or opening, respectively. One of the early events in the signalling mechanism is the rapid influx of calcium ions into the guard cells. However, the identity of the channel through which the ions move in response to the presence of a pathogen was unknown.
The international team has shown that OSCA1.3 is the long sought-after channel.
The identification of this channel has implications for the development of crops that are more resistant to disease. It is important to ensure that closure occurs when there is a real and significant threat, and also important to prevent false alarms.
Achieving an optimum balance would achieve significant agricultural benefits.
Professor Cyril Zipfel, The Sainsbury Laboratory
