The impact of temperature on balancing immune responsiveness and growth in Arabidopsis.

Plants have evolved polymorphic immune receptors to recognize pathogens causing disease. However, triggering of resistance needs to be tuned to the local environment to maintain a balance between defense and growth. We consider here the impact of temperature as a key environmental factor influencing immune pathway activation in Arabidopsis. Genetic compensatory and molecular buffering mechanisms affecting the diversification, functionality and subcellular dynamics of immune receptors, reveal multiple points at which temperature intersects with host resistance signaling systems, including a role of at least one receptor in sensing temperature change. Analysis of temperature-dependent autoimmunity caused by allelic mismatches in hybrids of evolutionary diverged Arabidopsis accessions is illuminating processes by which plants maintain 'poise' between immune responsiveness and fitness in natural populations.