When plants paint their leaves purple

Acclimation enables plants to survive stress via mechanisms like anthocyanin production. A genetic screen identified ILP1, an upstream regulator of anthocyanin biosynthesis with poorly understood metabolic roles. Multi-omics and physiological analyses showed that ilp1 mutants under high light accumulate excess sugars and low amino acids, disrupting carbon–nitrogen balance. ILP1, particularly its GC-rich DNA-binding domain, represses sugar buildup. Spliceosomal mutants NTR1, PRL1, and PRP8 share similar phenotypes, revealing the spliceosome’s key role in metabolic regulation during acclimation.