Effector‐mediated partial and nonhost disease resistance in wheat

Plants are considered to have three major forms of resistance against pathogen infection. The first is ‘non host resistance’, which operates broadly at the species level, meaning all members of a plant species generally resist all members of the would-be pathogen species. The other two systems operate at the ‘host’ level. ‘Qualitative host resistance’ is seen when an individual plant cultivar (or genotype)completely resists attempted attack by an individual pathogen strain, whilst ‘partial resistance’ is when a plant cannot completely defend itself. Each of these systems have some underlying molecular principles which will be outlined later. In this issue of New Phytologist, Meile et al.(2023; pp. 1562–1577) describe a novel mechanism by which both partial and non host resistance can be achieved in wheat facing the fungal pathogen Zymoseptoria tritici and its closely related species.