Stone cells in fruits of pear (Pyrus pyrifolia) negatively influence fruit quality because their lignified cell walls impart a coarse and granular texture to the fruit flesh. We generate RNA-seq data from the developing fruits of 206 pear cultivars with a wide range of stone cell contents and use a systems genetics approach to integrate co-expression networks and expression quantitative trait loci (eQTLs) to characterize the regulatory mechanisms controlling lignocellulose formation in the stone cells of pear fruits. Our data with a total of 35,897 expressed genes and 974,404 SNPs support the identification of seven stone cell formation modules and the detection of 139,515 eQTLs for 3229 genes in these modules. Focusing on regulatory factors and using a co-expression network comprising 39 structural genes, we identify PbrNSC as a candidate regulator of stone cell formation. We then verify the function of PbrNSC in regulating lignocellulose formation using both pear fruit and Arabidopsis plants and further show that PbrNSC can transcriptionally activate multiple target genes involved in secondary cell wall formation. This study generates a large resource for studying stone cell formation and provides insights into gene regulatory networks controlling the formation of stone cell and lignocellulose.

中文翻译：

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系统遗传学方法揭示 PbrNSC 作为梨果实石细胞中木质素和纤维素生物合成的调节剂

梨果实中的石细胞 (Pyrus pyrifolia) 会对果实质量产生负面影响，因为它们的木质细胞壁赋予果肉粗糙和颗粒状的质地。我们从具有广泛石细胞含量的 206 个梨品种的发育果实中生成 RNA-seq 数据，并使用系统遗传学方法整合共表达网络和表达数量性状基因座 (eQTL) 来表征控制木质纤维素形成的调控机制在梨果实的石细胞中。我们的数据共有 35,897 个表达基因和 974,404 个 SNP，支持对七个石细胞形成模块的识别和对这些模块中 3229 个基因的 139,515 个 eQTL 的检测。专注于调控因子，使用包含 39 个结构基因的共表达网络，我们将 PbrNSC 鉴定为石细胞形成的候选调节剂。然后，我们使用梨果实和拟南芥植物验证 PbrNSC 在调节木质纤维素形成中的功能，并进一步表明 PbrNSC 可以转录激活参与次生细胞壁形成的多个靶基因。这项研究为研究石细胞形成提供了大量资源，并提供了对控制石细胞和木质纤维素形成的基因调控网络的见解。