枸杞(Lycium barbarum)是重要经济林树种, 其扦插繁殖效率与不定根形成密切相关, 但枸杞不定根形成相关分子机制尚不明确, 制约了枸杞的规模化繁育及高效利用。为探究枸杞不定根发生的转录组差异, 本研究以3种生根能力差异的枸杞种质为材料, 通过水培试验分析其不定根发生过程中的转录水平差异。结果显示, 转录组测序分析鉴定出6448个差异表达基因(DEGs), 其中L-vs-H组DEGs数量最多, 达4413个, 包括上调2583个和下调1830个。转录因子分析鉴定出281个转录因子, 以MYB、AP2/ERF和bHLH家族为主, 且表达模式存在差异。GO富集分析发现1714个DEGs被富集到32个GO条目中, KEGG富集分析表明DEGs主要富集于苯丙烷生物合成和植物激素信号转导通路。其中, MYB19 (Lba07g01820)是苯丙烷通路中的核心基因, TIR1 (Lba08g00069)是植物激素信号转导通路中的核心基因, 它们在枸杞不定根发生过程中发挥重要作用。qRT-PCR验证了转录组数据的可靠性。本研究首次在枸杞中解析了不定根形成的转录调控网络, 为木本植物根系发育机制提供了新见解, 初步揭示了枸杞不定根形成的分子机理, 为枸杞及其他木本植物的遗传改良奠定了重要的理论基础。

INTRODUCTION: This study investigates the transcriptional levels of adventitious root formation in different Lycium barbarum genotypes with varying root-forming abilities and aims to identify key genes involved in this process. The findings will provide a theoretical basis for in-depth research on the molecular mechanisms underlying adventitious root formation in wolfberry. 

RATIONALE: Three wolfberry genotypes with different root-forming abilities were used as experimental materials. A hydroponic experiment was conducted to analyze the transcriptional differences during adventitious root formation.

RESULTS: Transcriptome sequencing identified 6448 differentially expressed genes (DEGs), with the L-vs-H group having the highest number of DEGs at 4413, including 2583 upregulated and 1830 downregulated genes. A total of 281 transcription factors were identified, mainly from the MYB, AP2/ERF, and bHLH families, with distinct expression patterns. GO enrichment analysis revealed that 1714 DEGs were enriched in 32 GO terms. KEGG enrichment analysis indicated that DEGs were mainly enriched in the phenylpropanoid biosynthesis and plant hormone signal transduction pathways. Among these, MYB19 (Lba07g01820) is a core gene in the phenylpropanoid pathway, and TIR1 (Lba08g00069) is a core gene in the plant hormone signal transduction pathway. Both genes play crucial roles in adventitious root formation in wolfberry. qRT-PCR validated the reliability of the transcriptome data. 

CONCLUSION: This study elucidates the molecular mechanisms of adventitious root formation in wolfberry and lays a theoretical foundation for the genetic improvement and efficient propagation of wolfberry and other woody plants.

Schematic diagram of transcriptomic analysis of adventitic root generation under hydroponics of Lycium barbarum