Zhang He, Gao Siyang, Yin Mingxin, Xu Mingyang, Wang Tianye, Li Xinyue, Du Guodong
College of Horticulture, Shenyang Agricultural University, Shenyang 110866, China.
General Station of Agricultural Technology Extension, Xinjiang Production and Construction Corps, Urumqi 830011, China.
Hortic Res. 2025 Apr 9;12(7):uhaf102. doi: 10.1093/hr/uhaf102. eCollection 2025 Jul.
Lignin deposition in stone cells is a critical factor that limits pear fruit quality, affecting their market value. Calcium ions (Ca ) play an essential role in lignin biosynthesis during fruit stone cell production. However, the genetic mechanisms underlying the Ca regulated lignin synthesis in stone cell formation are not fully understood. In this study, we identified an NAC transcription factor (TF) PuNAC21, which is repressed by CaCl treatment. PuNAC21 bound directly to the lignin biosynthesis gene peroxidase 42-like (-like) promoter, Ca reduced pear fruit stone cell production dependent on PuNAC21 positively regulating -like expression. Furthermore, PuNAC21 directly regulated the expression of , a TF involved in lignin biosynthesis by binding to -like and caffeoyl-CoA-O-methyltransferase 1() promoters. Moreover, PuNAC21 interacted with PuDof2.5 to form a transcriptional regulatory module, lowering the transcription of -like and after Ca treatment, which contributed to decrease pear stone cells production. Our results revealed Ca-induced PuNAC21-PuDof2.5-PuPRX42-like/PuCCoAOMT1 regulatory module inhibited lignin biosynthesis, giving important insights into reducing the stone cell content in pears via molecular breeding.
木质素在石细胞中的沉积是限制梨果实品质的关键因素，影响其市场价值。钙离子（Ca）在果实石细胞形成过程中的木质素生物合成中起着至关重要的作用。然而，Ca调控石细胞形成过程中木质素合成的遗传机制尚未完全明确。在本研究中，我们鉴定出一个NAC转录因子（TF）PuNAC21，其受氯化钙处理抑制。PuNAC21直接结合到木质素生物合成基因过氧化物酶42样（-样）启动子上，Ca通过正向调控-样表达降低梨果实石细胞的产生。此外，PuNAC21通过结合-样和咖啡酰辅酶A-O-甲基转移酶1（）启动子直接调控参与木质素生物合成的转录因子的表达。此外，PuNAC21与PuDof2.5相互作用形成转录调控模块，在Ca处理后降低-样和的转录，这有助于减少梨石细胞的产生。我们的结果揭示了Ca诱导的PuNAC21-PuDof2.5-PuPRX42样/PuCCoAOMT1调控模块抑制木质素生物合成，为通过分子育种降低梨中石细胞含量提供了重要见解。
