Transcriptional programs controlling sporulation in Phytophthora respond to nutrition, humidity, and cryptochrome-mediated light signals.

Over 4000 genes are up-regulated during sporulation in P. infestans, with nitrogen limitation and cryptochrome-mediated light signals influencing the process.

• Why it matters: Understanding how environmental factors regulate sporulation in Phytophthora is crucial for managing plant diseases caused by these pathogens, yet little is known about their transcriptional responses to such cues.
• What they did: Researchers studied time courses of P. infestans on media and tomato leaves, identifying genes associated with sporulation, and used metabolomic, gene silencing, and comparative analyses to explore environmental influences.
• The result: Sporulation is triggered mainly by nitrogen limitation and involves a cryptochrome-dependent light response, with humidity regulating a late developmental checkpoint, revealing species-specific transcriptional rewiring.