Translocon Subunits of the COP9 Signalosome Complex Are a Central Hub for Regulating Multiple Photoresponsive Processes and Autophagic Flux in .

Photodependent processes, including circadian rhythm, autophagy, ubiquitination, neddylation/deneddylation, and metabolite biosynthesis, profoundly influence microbial pathogenesis. Although a photomorphogenesis signalosome (COP9/CSN) has been identified, the mechanism by which this large complex contributes to the pathophysiological processes in filamentous fungi remains unclear. Here, we identified eight CSN complex subunits in the rice blast fungus and functionally characterized the translocon subunits containing a nuclear export or localization signal (NES/NLS). Targeted gene replacement of these CSN subunits, including , , , , and , attenuated vegetative growth and conidiation and rendered the deletion strains nonpathogenic. deletion significantly suppressed arachidonic acid catabolism, and compromised cell wall integrity in . Surprisingly, we also discovered that MoCSN subunits, particularly MoCsn7, are required for the cAMP-dependent regulation of autophagic flux. Therefore, MoCSN significantly contributes to morphological, physiological, and pathogenic differentiation in by fostering cross-talk between multiple pathways.