Wang Qi, Wu Xinyi, Ren Mei, Zhang Fanghang, Zhang Yang, Wang Yueyang, Li Wen, Xie Zhihua, Qi Kaijie, Zhang Shaoling, Shiratake Katsuhiro, Niu Yingying, Tao Shutian
Sanya Institute, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
College of Horticulture, Anhui Agricultural University, Hefei, 230036, China.
Mol Hortic. 2025 May 7;5(1):27. doi: 10.1186/s43897-025-00149-z.
The presence of stone cells in pear fruit, caused by lignified secondary cell walls (SCWs), leads to a grainy texture in the fruit flesh, thereby compromising its overall quality. Lignification is influenced by various environmental signals, including light, however the underlying mechanism are poorly understood. This study reveals that SCW thickening and lignin accumulation in stone cells were regulated by a blue light signal, mediated through the activation of PbNSC by PbbHLH195. The results revealed that the stone cell formation was prompted by supplementary with blue light, with lignin accumulation linked to the upregulation of the NAC STONE CELL PROMOTING FACTOR (PbNSC). PbbHLH195 was identified as a novel molecular hub connecting lignification to blue light signal through its physical interaction with PbCRY1a. The biochemical and functional analysis indicates that PbbHLH195 contributes to stone cell lignification by activating the promoter of PbNSC. Our findings offer novel insights into the mechanisms of lignin biosynthesis in response to blue light, identifying valuable genetic targets for enhancing the fruit quality of pear.
梨果实中石细胞的存在是由木质化的次生细胞壁（SCWs）引起的，这会导致果肉质地粗糙，从而影响其整体品质。木质化受包括光在内的各种环境信号影响，但其潜在机制尚不清楚。本研究表明，石细胞中SCW增厚和木质素积累受蓝光信号调控，该信号通过PbbHLH195激活PbNSC介导。结果显示，补充蓝光可促进石细胞形成，木质素积累与NAC石细胞促进因子（PbNSC）的上调有关。PbbHLH195通过与PbCRY1a的物理相互作用被鉴定为连接木质化与蓝光信号的新型分子枢纽。生化和功能分析表明，PbbHLH195通过激活PbNSC启动子促进石细胞木质化。我们的研究结果为响应蓝光的木质素生物合成机制提供了新见解，为提高梨果实品质确定了有价值的基因靶点。
