目的 发掘生长素信号转导途径中可能参与三岛柴胡Bupleurum. falcatum侧根发育的关键基因。方法 采用Illumina Hiseq2500高通量测序平台对三岛柴胡不同发育阶段的根组织进行转录组测序，筛选差异表达的生长素信号转导基因。通过使用外源生长素（indole-3-acetic acid，IAA）与生长素抑制剂（2,3,5-triiodobenzoic acid，TIBA）处理苗期柴胡，考察生长调节剂对三岛柴胡侧根发育及差异表达基因的影响。结果 在三岛柴胡的苗期根转录组中共鉴定到138个属于生长素信号转导通路中的差异表达基因，其中73个基因在15日龄的三岛柴胡主根（S3）中特异性高表达。相关性分析表明，BfIAA9/14/16、BfARF6/19、BfGH3.6、BfLAX3等31个差异基因表达模式高度相关，可能共同参与了三岛柴胡的侧根发育过程。外源激素诱导结果显示，低浓度的IAA和TIBA处理均可显著增加三岛柴胡侧根数目，并促进BfIAA9/14/16、BfARF19等基因的表达。进一步证实了转录组的筛选结果的准确性，其中BfIAA9/14/16、BfARF19可能是正向调控三岛柴胡侧根发育的关键基因。结论 揭示了三岛柴胡根系在不同发育阶段和组织中生长素信号转导通路基因的显著差异表达模式，其中在S3组织中高表达的基因可能与侧根发育密切相关。

Objective To identify key genes involved in the auxin signal transduction pathway that may participate in the lateral root development of Bupleurum falcatum. Methods Transcriptome sequencing of root tissues at different developmental stages of B. falcatum was performed using the Illumina HiSeq2500 high-throughput sequencing platform to screen for differentially expressed auxin signaling genes. The effects of exogenous IAA and TIBA on the lateral root development and expression of differentially expressed genes in B. falcatum seedlings were examined. Results A total of 138 DEGs related to the auxin signal transduction pathway were identified in the transcriptome data of seedling-stage B. falcatum, with 73 genes specifically highly expressed in 15-day-old the main root (S3). Correlation analysis revealed that 31 DEGs, including BfIAA9/14/16, BfARF6/19, BfGH3.6, and BfLAX3, showed highly correlated expression patterns, suggesting their potential involvement in the lateral root development of B. falcatum. Exogenous hormone induction results showed that low concentrations of IAA and TIBA treatments significantly increased the number of lateral roots in B. falcatum and promoted the expression of genes such as BfIAA9/14/16 and BfARF19. These results confirmed the accuracy of the transcriptome screening, indicating that BfIAA9/14/16 and BfARF19 may be key positive regulators of lateral root development in B. falcatum. Conclusion This study reveals significant differential expression patterns of auxin signaling pathway genes in the roots of B. falcatum at different developmental stages and tissues, with genes highly expressed in S3 tissue potentially being closely related to lateral root development.

R286.12

四川省国际合作项目(2023YFH0044,2023YFH0018);国家现代农业产业技术体系(CARS-21)