Aquilaria sinensis MYB‐Like Transcription Factor AsMYB1 Promotes 2‐(2‐Phenylethyl)Chromone Biosynthesis Through Interacting With 14‐3‐3 Family Protein AsGRF1

ABSTRACT 2‐(2‐Phenylethyl)chromones (PECs) are the primary constituents of agarwood, a valuable aromatic resin widely used in traditional oriental medicine and incense production, exhibiting diverse pharmacological activities. While we have previously reported a polyketide synthase (AsPECPS) playing a crucial role in the biosynthesis of PECs in agarwood, the intrinsic regulatory mechanisms underlying PEC biosynthesis remain largely elusive. Here, we successfully characterised a new 1R‐subtype myeloblastosis (MYB) transcription factor (AsMYB1) from Aquilaria sinensis whose expression is significantly induced under salt treatment. Further overexpression, RNA interference (RNAi) and gene‐editing experiments confirmed the positive regulatory role of AsMYB1 in PEC biosynthesis. AsMYB1 specifically bound to cis ‐elements in the promoter of AsPECPS to enhance its transcription, thereby promoting PEC accumulation under salt stress. A 14‐3‐3 family protein designated AsGRF1 was characterised to interact with AsMYB1 both in vivo and in vitro, and knockdown or knockout of AsGRF1 led to a dramatic reduction in AsPECPS expression and PECs’ accumulation. Furthermore, AsGRF1 may positively facilitate AsMYB1‐mediated activation of PEC production under salt stress by elevating AsPECPS expression through increasing the transcriptional activity, nuclear localisation and stability of AsMYB1. Our findings suggest that the AsGRF1‐AsMYB1‐AsPECPS module synergistically facilitates salt‐induced PEC metabolism, inspiring potential biotechnological strategies to improve agarwood quality through metabolic engineering.