A lncRNA fine-tunes salicylic acid biosynthesis to balance plant immunity and growth

Constitutive activation of plant immunity is detrimental to plant growth and development. Here, we uncover the role of a long non-coding RNA (lncRNA) in fine-tuning the balance of plant immunity and growth. We find that a lncRNA termed salicylic acid biogenesis controller 1 (SABC1) suppresses immunity and promotes growth in healthy plants. SABC1 recruits the polycomb repressive complex 2 to its neighboring gene NAC3, which encodes a NAC transcription factor. to decrease NAC3 transcription via H3K27me3. NAC3 activates the transcription of isochorismate synthase 1 (ICS1), a key enzyme catalyzing salicylic acid (SA) biosynthesis. SABC1 thus represses SA production and plant immunity via decreasing NAC3 and ICS/transcriptions. Upon pathogen infection, SABC1 is downregulated to derepress plant resistance to bacteria and viruses. Together, our findings reveal lncRNA SABC1 as a molecular switch in balancing plant defense and growth by modulating SA biosynthesis.

Automated summary

A long non-coding RNA called SABC1 has been discovered to play a crucial role in balancing plant immunity and growth. SABC1 suppresses plant immunity and promotes growth by regulating the neighboring gene NAC3. This lncRNA acts as a molecular switch in modulating the production of salicylic acid, a key molecule in plant defense against pathogens.