Transfer and modification of NLR proteins for virus resistance in plants

NLR proteins confer resistance to multiple types of biotrophic pathogens, including viruses. NLRs are highly variable in sequence, suggesting that they are under selection pressure, but also that they may be manipulated to generate proteins with new recognition specificities. However, transferring of effective NLRs and engineering new specificities is subject to a number of constraints. Recent insights into NLR function suggest a number of reasons for these difficulties and new techniques have increased our ability to identify effective NLRs. This review discusses how this new information may allow researchers to better take advantage of the potential of NLRs for creating virus-resistant plants, including the identification, modification and transfer of NLRs as well as re-engineering NLRs to recognize viruses based on viral protein function.