Nicotiana benthamiana leaf showing hypersensitive response
Marina Pais (TSL) & Andrew Davis (JIC)
Scientists in The Sainsbury Laboratory on the Norwich Research Park are studying the interaction between plants and pathogens. The hypersensitive response (HR) is one of the defence mechanisms plants use against pathogens. It involves the death of plant cells in the infected area, which in turn impairs pathogen growth. This mechanism is particularly effective against biotrophic plant pathogens (pathogens that require the plants to stay alive). In this example, the HR was triggered by the transient expression of a plant resistance protein and its cognate pathogen effector in 6 areas of the leaf. Phenolic compounds are produced during the HR, which can be imaged as yellow/green spots under UV light. The red colour in the rest of the leaf is due to the emission of chlorophyll in this lighting condition.