Key Laboratory of the Ministry of Education for Protection and Utilization of Special Biological Resources in the Western, School of Life Science, Ningxia University, Yinchuan 750021, Ningxia, China.
College of Life Sciences, Gannan Normal University, Ganzhou, Jiangxi 341000, China; Guangdong Provincial Key Laboratory of Applied Botany, State Key Laboratory of Plant Diversity and Specialty Crops, South China Botanical Garden, Chinese Academy of Sciences, South China National Botanical Garden, Guangzhou 510650, China.
Int J Biol Macromol. 2024 Jan;254(Pt 2):127970. doi: 10.1016/j.ijbiomac.2023.127970. Epub 2023 Nov 7.
Lycium barbarum polysaccharides (LBPs) are the primary bioactive components in fruits of L. barbarum, commonly known as goji berry. Despite significant progress in understanding the chemical structures and health benefits of LBPs, the biosynthesis and regulation of LBPs in goji berry remains largely unknown. In this study, physiological indicators, including LBPs, were monitored in goji berry during fruit development and ripening (FDR), suggesting that pectin might be the major component of LBPs with increased content reaching 235.8 mg/g DW. Proteomic and transcriptomic analysis show that 6410 differentially expressed genes (DEGs) and 2052 differentially expressed proteins (DEPs) were identified with overrepresentation of flavonoids and polysaccharides-related gene ontology (GO) terms and KEGG pathways. Weighted gene co-expression network analysis (WGCNA) showed that LBPs coexpress with genes involved in pectin biosynthesis (LbGALS3, LbGATL5, LbQUA1, LbGAUT1/4/7, LbRGGAT1, LbRRT1/7, and LbRHM2), modification (LbSBT1.7), and regulation (LbAP2, LbGL2 LbTLP2, LbERF4, and LbTTG2), as well as with novel transcription factors (LbSPL9 and LbRIN homologs) and glycosyltransferases. Transgenic hairy roots overexpressing LbRIN validated that LbRIN modulate the expression of WGCNA-predicted regulators, including LbERF4, LbTTG2, and LbSPL9. These findings suggest that the biosynthesis and regulation of LBPs is conserved partially to those in Arabidopsis pectin. Taken together, this study provides valuable insights into the biosynthesis and regulation of LBPs, which can facilitate future studies on synthetic biology applications and genetic improvement of LBPs.
枸杞多糖（LBPs）是枸杞果实中主要的生物活性成分，通常被称为枸杞。尽管人们在理解 LBPs 的化学结构和健康益处方面取得了重大进展，但枸杞中 LBPs 的生物合成和调控仍知之甚少。在这项研究中，监测了枸杞果实发育和成熟过程中的生理指标，包括 LBPs，提示果胶可能是 LBPs 的主要成分，其含量增加，达到 235.8mg/g DW。蛋白质组学和转录组学分析表明，鉴定出 6410 个差异表达基因（DEGs）和 2052 个差异表达蛋白（DEPs），其中黄酮类和多糖相关基因本体论（GO）术语和 KEGG 途径的基因显著富集。加权基因共表达网络分析（WGCNA）表明，LBPs 与参与果胶生物合成（LbGALS3、LbGATL5、LbQUA1、LbGAUT1/4/7、LbRGGAT1、LbRRT1/7 和 LbRHM2）、修饰（LbSBT1.7）和调控（LbAP2、LbGL2、LbTLP2、LbERF4 和 LbTTG2）的基因，以及与新型转录因子（LbSPL9 和 LbRIN 同源物）和糖基转移酶共同表达，过表达 LbRIN 的转基因毛状根验证了 LbRIN 调节 WGCNA 预测的调节剂的表达，包括 LbERF4、LbTTG2 和 LbSPL9。这些发现表明，LBPs 的生物合成和调控部分与拟南芥果胶的生物合成和调控保守。综上所述，本研究为 LBPs 的生物合成和调控提供了有价值的见解，这有助于未来对 LBPs 的合成生物学应用和遗传改良的研究。
