PuRBOHF-PuPRX42-like complex activates lignin biosynthesis for stone cell formation in pear fruit

Lignin deposition in stone cells is critical for the quality of pear fruit. NADPH oxidase (RBOH), a membrane-bound respiratory burst oxidase homolog, enzymatically generates reactive oxygen species (ROS) to critically regulate diverse physiological processes in plants. Nevertheless, the genetic mechanisms that govern RBOH-regulated lignin biosynthesis in the context of stone cell formation remain inadequately elucidated. In this research, we observed a significant increasing of stone cell content associated with expression of PuPRX42-like (peroxidase 42-like). In addition, the stage-specific expression of PuRBOHF was higher in stone cells than in cells of other tissues, thereby the production of ROS and lignin biosynthesis increased. As a positive regulator of stone cell, PuRBOHF interact with PuPRX42-like form a complex (PuRBOHF-PuPRX42-like), which markedly promote lignin biosynthesis and stone cell formation in pear fruit. Collectively, our results elucidated the molecular mechanisms underlying lignin biosynthesis in stone cells formation of pear fruits.