芍药种子下胚轴休眠相关基因的cDNA-AFLP分析

cDNA-AFLP Analysis of Dormancy-related Genes in Seed Hypocotyl of Paeonia lactiflora

旨在探讨芍药种子下胚轴的休眠机理,采用cDNA-AFLP技术对层积0 d和根部露白两个时期的芍药种子进行基因差异表达分析。利用256对引物组合进行扩增,筛选获得3 600个差异表达转录衍生片段(TDFs),成功回收到1 200个TDFs,选取500个TDFs对其克隆测序,共得到42个有效序列。经BLAST比对发现,其中30个TDFs与已知功能基因同源,分别参与芍药种子下胚轴休眠过程中的基因表达调控、信号转导、逆境胁迫、物质与能量代谢等过程,9个TDFs与功能未知基因及假想蛋白同源,另有3个TDFs为无同源序列,可能是新的未知基因,这些基因有助于更好地阐明芍药种子下胚轴休眠机理。

To explore the dormancy mechanism of seed hypocotyl ofPaeonia lactiflora and isolate dormancy-related genes fromP. lactiflora, a cDNA-AFLP technology was used to identify differentially expressed genes between the stages of seeds with stratification for 0 d and germination. A total of 3 600 differentially expressed transcript-derived fragments（TDFs）were screened by selective PCR amplification using 256 primer combinations, and 1 200 TDFs were recovered successfully. Then selected 500 TDFs were cloned and sequenced, and 42 effective sequences were obtained. Bioinformatics analysis with BLAST showed that 30 TDFs were homologous to the known functional genes, which involved in gene expression regulation, signal transduction, stress responding, material and energy metabolism etc. during the dormancy of seed hypocotyl ofP. lactiflora. Nine TDFs were similar to genes of unknown functions and hypothetical proteins, and another 3 TDFs had no sequence homology to GenBank entries and might be new unknown genes, which could help us to clarify the mechanism of seed hypocotyl dormancy of P. lactiflora.