目的 基于全长转录组测序挖掘掌叶大黄Rheum palmatum GRAS基因（RpGRASs）家族成员，并分析其在掌叶大黄叶、根和根茎中的表达及茉莉酸甲酯（methyl jasmonate，MeJA）处理下的表达模式。方法 利用生物信息学对掌叶大黄GRAS成员进行系统发育、保守结构域、蛋白理化性质和亚细胞定位分析；基于转录组数据对RpGRASs基因的组织表达模式进行转录组测序（RNA sequencing，RNA-seq）分析，使用实时定量逆转录聚合酶链式反应（real-time quantitative reverse transcription PCR，RT-qPCR）对筛选到的3个RpGRASs进行MeJA处理下的表达模式检测。结果 在掌叶大黄全长转录组数据中共鉴定得到39个RpGRASs成员。RpGRASs蛋白主要为不稳定亲水蛋白，定位于细胞核、叶绿体和细胞质；各蛋白二级结构主要为无规则卷曲和α螺旋；系统发育将该家族分为PAT1、DELLA、HAM、SHR、SCR和SCL4/7 6个亚族；GRAS蛋白C端均含有典型的LHRI、VHIID、LHRII、PFYRE和SAW基序。RpGRASs基因表达具有组织特异性，在药用部位根及根茎中高表达的RpGRAS17、RpGRAS18、RpGRAS20受MeJA显著诱导。结论 掌叶大黄GRAS转录因子基因家族的系统鉴定及组织和MeJA诱导下的基因表达特征，为深入研究GRAS基因的功能奠定基础。

Objective The members of GRAS gene family in Rheum palmatum were extracted based on full-length transcriptome sequencing, and their expression in leaves, roots and rhizomas and under methyl jasmonate (MeJA) treatment were analyzed. Methods The phylogeny, conserved domain, protein physicochemical properties and subcellular localization of GRAS members of R. palmatum were analyzed by bioinformatics. RNA sequencing (RNA-seq) analysis was performed on the tissue expression patterns of RpGRASs genes based on transcriptome data, and real-time quantitative reverse transcription PCR (RT-qPCR) was used to detect the expression patterns of the three selected RpGRASs genes under MeJA treatment. Results A total of 39 RpGRASs members were identified from the full-length transcriptome data of R. palmatum. RpGRASs proteins were mainly unstable hydrophilic proteins located in the nucleus, chloroplast and cytoplasm. The secondary structure of each protein was mainly random coil and α helix. The family was divided into six subfamilies, namely PAT1, DELLA, HAM, SHR, SCR and SCL4/7. The C-terminal of GRAS protein contained typical LHRI, VHIID, LHRII, PFYRE and SAW motifs. The expression of RpGRASs gene was tissue-specific, and RpGRAS17, RpGRAS18 and RpGRAS20 which were highly expressed in the roots and rhizomes of medicinal parts were significantly induced by MeJA. Conclusion The systematic identification and gene expression analyses of GRAS transcription factor family lay a foundation for further gene function analyses of GRASs in R. palmatum.

R286.2

陕西省教育厅专项科研计划项目（23JK0401）;咸阳市科学技术研究发展计划项目（L2021-QCY-ZYYJJQ-X133）;陕西中医药大学学科创新团队项目（2019-QN01）