Understanding plant defences
When plants sense an attack by a pathogen, they typically kill off nearby tissues so as to isolate the attack and prevent spreading (localised cell death). In what has been called an arms race of sorts, pathogens have evolved 'effector proteins' to thwart this first line of defence. Plants, in retaliation, evolved an arsenal of 'resistance proteins'. The EU-funded 'Investigating how pathogen effector recognition by plant resistance proteins activates defence' (PLANT-DEF-MECH) project was set up to investigate how these resistance proteins initiate a defence response once they recognise pathogen effector proteins. Researchers studied the phenomenon using genetically engineered tobacco plants and other advanced molecular biology techniques. They found that two proteins, RRS1 and RPS4, work together to help activate plant defences. These proteins form part of a large group of resistance proteins that lure pathogen effector proteins as a result of their unique structures. As evidence for their cooperation, researchers determined that without the presence of RRS1, RPS4 cannot facilitate a controlled immune response. Furthermore, without the presence of RPS4, RRS1 remains inactive. These studies will lead a series of investigations into the structural interactions of proteins during defence responses. Future work will focus on how this information can be applied to plants and pathogens to confer sustainable immunity to important crops.
Keywords
Plant defences, effector proteins, resistance proteins, RRS1, RPS4
