椰枣幼苗地上部和根部显微结构观察和植物激素相关差异基因分析

Microstructure Observation and Hormone-related Differential Genes Analysis of the Date palm Seedlings about Shoots and Roots

椰枣是干旱和半干旱地区重要的木本粮食作物之一,其地上部和根部形态显微结构差异明显,然而内在的差异转录机制不清楚。为探明椰枣幼苗地上部和根部差异机制,本研究对椰枣幼苗的地上部和根部进行转录组测序,重点分析植物激素信号转导通路的生长素、细胞分裂素、脱落酸、赤霉素、水杨酸和茉莉素相关基因。结果表明,地上部和根部形态与显微结构差异明显,叶片具有圆球形的叶肉细胞,茎中有较为密集的细胞核,根的中间为中柱。转录组分析发现,共有7101个差异表达基因,上调3042个,下调4059个。差异表达基因的KEGG通路分析结果显示,前5条通路中的第2条途径为植物激素信号转导合成途径。地上部生长素TIR1,赤霉素GID1、DELLA、TF,水杨酸NPR1、PR-1基因高表达;而根部生长素AUX1、PIN,细胞分裂素AHP、B-ARR、A-ARR、BIN3,水杨酸TGA,茉莉素JAZ,脱落酸PP2C、ABF、SnRK2基因高表达。椰枣幼苗的地上部和根部的植物激素相关基因具有组织表达特异性,参与调控椰枣幼苗的发育机制不同,为后续外源激素调控椰枣幼苗地上部和根的生长发育提供基础。

Date palm is one of the most important woody food crops in arid and semi-arid regions.The morphological and microscopic structure of the shoot and root are different,while the transcription mechanism is unclear.In order to provide theoretical reference for understanding the mechanism of difference between shoot and root of date palm seedlings,transcriptome sequencing was conducted on the shoot and root of date palm seedlings,the plant hormone signal transduction pathways of auxin,cytokinin,abscisic acid,gibberellin,salicylic acid and jasmonic acid-related genes were analyzed.The results indicated that the morphological and microscopic structure of the shoot and root are different,the leaves have spherical mesophyll cells,the stems have relatively dense nuclei,and the middle of the root is the stele.Transcriptome analysis revealed there are 7101 differentially expressed genes,3042 upregulated and 4059 downregulated.KEGG pathway analysis of differentially expressed genes showed that the second pathway was a plant hormone signal transduction.Genes of auxin TIR1,gibbecellins GID1, DELLA, TF, and salicylic acid NPR1 and PR-1 were highly expressed in shoot. However, thegenes of auxin AUX1 and PIN, cytokinin AHP, B-ARR, A-ARR and BIN3 genes, salicylic acid TGA, jasmonic acidJAZ, abscisic acid PP2C, ABF and SnRK2 genes were highly expressed in root. The plant hormone-related genesin shoot and root of date palm seedlings have tissue-specific expression, and the mechanisms involved in theregulation of the development of date palm seedlings are different, which lays a foundation for the subsequentregulation of the growth and development of shoot and root of date palm seedlings by exogenous hormones.