The StJAZ1-Like-StPIF02-StPIN3 Module Regulates Shoot and Tuber Apical Dominance in Potato.

Abstract

Apical dominance is a key determinant of plant architecture and yield formation in crops. Auxin and jasmonic acid are crucial endogenous regulators of this process, yet their functions in the above‐ground shoots and underground modified stems (tubers) of asexually propagated potato plants remain largely unclear. Here, we demonstrate that the jasmonate pathway component StJAZ1‐like promotes the release of apical dominance in potato. StJAZ1‐like overexpression enhanced axillary bud outgrowth, increased shoot branching and triggered multi‐bud sprouting from individual tuber eyes. Transcriptome profiling of dormant axillary buds revealed pronounced alterations in hormone‐related pathways, including marked upregulation of the auxin efflux carrier StPIN3 , accompanied by reduced indole‐3‐acetic acid (IAA) and abscisic acid (ABA) levels in axillary buds. Consistently, functional analyses demonstrated that StPIN3 positively regulates lateral branching and tuber sprouting, indicating that StPIN3 acts downstream of StJAZ1‐like. Mechanistically, StJAZ1‐like physically interacts with StPIF02, a bHLH transcription factor. StPIF02 directly binds the StPIN3 promoter and activates its transcription. Collectively, our results suggest a StJAZ1‐like–StPIF02–StPIN3 regulatory module that links jasmonate with auxin to modulate apical dominance in potato, providing candidate pathways for designing an ideal multi‐branched plant architecture in potato.