PubMed · 2026-03-24
Scientists discovered a molecular switch called IAA16 that controls both plant growth and disease resistance, and found that plant viruses hijack this switch to weaken crops. Understanding this mechanism could help breed crops that grow well AND fight off diseases simultaneously.
The protein IAA16 acts as a negative regulator of both plant growth (auxin signaling) and immune response (salicylic acid signaling), making it a rare dual-pathway master regulator.
Geminivirus-betasatellite complexes deploy a viral protein (βC1) that blocks the plant's normal process of breaking down IAA16, artificially elevating its levels to suppress both growth and immunity simultaneously.
This viral manipulation of IAA16 was confirmed to be conserved across both model and crop plants, including tomato, suggesting broad relevance for agricultural applications.
