目的 基于全長轉錄組測序挖掘掌葉大黃Rheum palmatum GRAS基因（RpGRASs）家族成員，并分析其在掌葉大黃葉、根和根莖中的表達及茉莉酸甲酯（methyl jasmonate，MeJA）處理下的表達模式。方法 利用生物信息學對掌葉大黃GRAS成員進行系統(tǒng)發(fā)育、保守結構域、蛋白理化性質和亞細胞定位分析；基于轉錄組數(shù)據(jù)對RpGRASs基因的組織表達模式進行轉錄組測序（RNA sequencing，RNA-seq）分析，使用實時定量逆轉錄聚合酶鏈式反應（real-time quantitative reverse transcription PCR，RT-qPCR）對篩選到的3個RpGRASs進行MeJA處理下的表達模式檢測。結果 在掌葉大黃全長轉錄組數(shù)據(jù)中共鑒定得到39個RpGRASs成員。RpGRASs蛋白主要為不穩(wěn)定親水蛋白，定位于細胞核、葉綠體和細胞質；各蛋白二級結構主要為無規(guī)則卷曲和α螺旋；系統(tǒng)發(fā)育將該家族分為PAT1、DELLA、HAM、SHR、SCR和SCL4/7 6個亞族；GRAS蛋白C端均含有典型的LHRI、VHIID、LHRII、PFYRE和SAW基序。RpGRASs基因表達具有組織特異性，在藥用部位根及根莖中高表達的RpGRAS17、RpGRAS18、RpGRAS20受MeJA顯著誘導。結論 掌葉大黃GRAS轉錄因子基因家族的系統(tǒng)鑒定及組織和MeJA誘導下的基因表達特征，為深入研究GRAS基因的功能奠定基礎。

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

陜西省教育廳專項科研計劃項目（23JK0401）;咸陽市科學技術研究發(fā)展計劃項目（L2021-QCY-ZYYJJQ-X133）;陜西中醫(yī)藥大學學科創(chuàng)新團隊項目（2019-QN01）