Ning Rongchun, Li Caixia, Fan Tingting, Ji Tingting, Xu Wenhua
Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China.
Qinghai Key Laboratory of Qinghai-Tibet Plateau Biological Resources, Xining 810008, China.
Plants (Basel). 2024 Sep 26;13(19):2693. doi: 10.3390/plants13192693.
(Royle) Ying, an endangered perennial medicinal herb, exhibits morpho-physiological dormancy in its seeds, requiring cold stratification for germination. However, the precise molecular mechanisms underlying this transition from dormancy to germination remain unclear. This study integrates transcriptome and plant hormone-targeted metabolomics techniques to unravel these intricate molecular regulatory mechanisms during cold stratification in seeds. Significant alterations in the physicochemical properties (starch, soluble sugars, soluble proteins) and enzyme activities (PK, SDH, G-6-PDH) within the seeds occur during stratification. To characterize and monitor the formation and transformation of plant hormones throughout this process, extracts from seeds at five stratification stages of 0 days (S0), 30 days (S1), 60 days (S2), 90 days (S3), and 120 days (S4) were analyzed using UPLC-MS/MS, revealing a total of 37 differential metabolites belonging to seven major classes of plant hormones. To investigate the biosynthetic and conversion processes of plant hormones related to seed dormancy and germination, the transcriptome of seeds was monitored via RNA-seq, revealing 65,372 differentially expressed genes associated with plant hormone synthesis and signaling. Notably, cytokinins (CKs) and gibberellins (GAs) exhibited synergistic effects, while abscisic acid (ABA) displayed antagonistic effects. Furthermore, key hub genes were identified through integrated network analysis. In this rigorous scientific study, we systematically elucidate the intricate dynamic molecular regulatory mechanisms that govern the transition from dormancy to germination in seeds during stratification. By meticulously examining these mechanisms, we establish a solid foundation of knowledge that serves as a scientific basis for facilitating large-scale breeding programs and advancing the artificial cultivation of this highly valued medicinal plant.
（罗伊尔）银不才是一种濒危的多年生药用草本植物，其种子表现出形态生理休眠特性，需要冷层积处理才能发芽。然而，从休眠到发芽这一转变背后的确切分子机制仍不清楚。本研究整合了转录组学和植物激素靶向代谢组学技术，以揭示种子冷层积过程中这些复杂的分子调控机制。层积处理期间，种子的理化性质（淀粉、可溶性糖、可溶性蛋白）和酶活性（PK、SDH、G-6-PDH）发生了显著变化。为了表征和监测整个过程中植物激素的形成和转化，使用超高效液相色谱-串联质谱法（UPLC-MS/MS）分析了种子在0天（S0）、30天（S1）、60天（S2）、90天（S3）和120天（S4）这五个层积阶段的提取物，共鉴定出属于七大类植物激素的37种差异代谢物。为了研究与种子休眠和发芽相关的植物激素的生物合成和转化过程，通过RNA测序监测种子的转录组，发现了65372个与植物激素合成和信号传导相关的差异表达基因。值得注意的是，细胞分裂素（CKs）和赤霉素（GAs）表现出协同作用，而脱落酸（ABA）则表现出拮抗作用。此外，通过整合网络分析确定了关键枢纽基因。在这项严谨的科学研究中，我们系统地阐明了种子在层积过程中从休眠到发芽转变所涉及的复杂动态分子调控机制。通过精心研究这些机制，我们奠定了坚实的知识基础，为促进大规模育种计划和推动这种高价值药用植物的人工栽培提供了科学依据。
