PDF(Pubmed)
Abstract：
Sand pear is the main cultivated pear species in China, and brown peel is a unique feature of sand pear. The formation of brown peel is related to the activity of the cork layer, of which lignin is an important component. The formation of brown peel is intimately associated with the biosynthesis and accumulation of lignin; however, the regulatory mechanism of lignin biosynthesis in pear peel remains unclear. In this study, we used a newly bred sand pear cultivar \'Xinyu\' as the material to investigate the biosynthesis and accumulation of lignin at nine developmental stages using metabolomic and transcriptomic methods. Our results showed that the 30 days after flowering (DAF) to 50DAF were the key periods of lignin accumulation according to data analysis from the assays of lignin measurement, scanning electron microscope (SEM) observation, metabolomics, and transcriptomics. Through weighted gene co-expression network analysis (WGCNA), positively correlated modules with lignin were identified. A total of nine difference lignin components were identified and 148 differentially expressed genes (DEGs), including 10 structural genes (PAL1, C4H, two 4CL genes, HCT, CSE, two COMT genes, and two CCR genes) and MYB, NAC, ERF, and TCP transcription factor genes were involved in lignin metabolism. An analysis of RT-qPCR confirmed that these DEGs were involved in the biosynthesis and regulation of lignin. These findings further help us understand the mechanisms of lignin biosynthesis and provide a theoretical basis for peel color control and quality improvement in pear breeding and cultivation.
摘要：
沙梨是我国主要的栽培梨品种,棕色果皮是沙梨的独特特征。棕色果皮的形成与软木层的活性有关，木质素是其中的重要成分。棕色果皮的形成与木质素的生物合成和积累密切相关；然而，梨皮木质素生物合成的调控机制尚不清楚。在这项研究中,我们使用新培育的沙梨品种“新余”作为材料，使用代谢组学和转录组学方法研究了九个发育阶段木质素的生物合成和积累。我们的结果表明，根据木质素测量的数据分析，开花后30天至50DAF是木质素积累的关键时期，扫描电镜(SEM)观察,代谢组学，和转录组学。通过加权基因共表达网络分析(WGCNA)，确定了与木质素呈正相关的模块。共鉴定出9个差异木质素组分和148个差异表达基因(DEGs),包括10个结构基因(PAL1，C4H，两个4CL基因，HCT,CSE,两个COMT基因，和两个CCR基因）和MYB，NAC,ERF,和TCP转录因子基因参与木质素代谢。RT-qPCR分析证实这些DEGs参与木质素的生物合成和调节。这些发现有助于我们进一步了解木质素生物合成的机理，并为梨育种和栽培中的果皮颜色控制和品质改良提供理论依据。
