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<div>Light is a cue that influences the behavior of foliar bacterial pathogens. Whereas plants exploit light signals to enhance defense against pathogens, we have shown that <i>Pseudomonas syringae </i>exploits light signals to influence movement and colonization, and this may enable it to evade circadian-based plant defenses. Far-red light is enriched relative to blue and red light in plant tissues due to blue/red absorption, enabling far-red light to be abundant within tissues and conducted over long distances through stems and roots. We discovered a much stronger response of <i>P. syringae </i>to far-red than to red or blue light, and a significant role of a bacteriophytochrome, a far-red light-sensing photosensory protein, in global gene expression patterns. We have also found that <i>P. syringae </i>integrates responses to far-red light, blue light and and water limitation, which are environmental signals that co-occur on leaves. The impact of far-red light and a bacteriophytochrome on >25% of the genes in the <i>P. syringae </i>genome illustrates a major role for light-sensing in <i>P. syringae </i>biology, consistent with the possibility that this pathogen and others exploit far-red light gradients as spatial and temporal cues within plant tissues.</div>