花生抗青枯病相关基因的差异表达

Differential expression of genes related to bacterial wilt resistance in peanut (Arachis hypogaea L.)

以抗青枯病花生品种‘远杂9102’和感病品种‘中花12’为材料,用高致病性青枯菌株对其进行接种处理,利用cDNA-AFLP技术,分析了侵染后48 h内5个时间点的基因表达情况。从256对引物组合中筛选到119对引物,扩增出709条差异表达的转录衍生片段(Transcript-derived fragment,TDF),包括抗病品种与感病材料的差异以及接种与未接种间的差异等6种差异表达模式。对其中98个TDF进行了克隆测序,结果显示,40个TDF与GenBank nr数据库中已有序列同源,功能涉及能量、代谢、信号转导、转录调控、逆境应答等等;15个TDF在数据库中找到同源序列,但蛋白功能未知;43个TDF在数据库中未找到同源序列,可能为一些新基因。对选取的差异表达TDF进行qRT-PCR分析,结果与cDNA-AFLP表达谱一致,其中TDF 32-54-1在前期构建的抗青枯病SSH文库中出现频次达到47次。文章推测,花生青枯病抗性可能受抗病抗逆、转录调控、信号转导、蛋白质储存代谢以及非生物胁迫等多方面相关基因的协同调控,TDF 32-54-1可能与花生青枯病抗性相关。

Peanut bacterial wilt （BW） caused by Ralstonia solanacearum is one of the most devastating diseases for pea- nut production in the world. It is believed that breeding and subsequent planting BW-resistant cultivars of peanut （Arachis hypogaea L.） should represent the most effective and economic means of controlling the disease. To illustrate the molecular mechanism of peanut resistant to BW, a BW-resistant cultivar, ＇Yuartza 9102＇, and a BW-sensitive one, ＇Zhonghua 12＇, were infected with Ralstonia solanacearum and differential expression of the genes related to BW-resistance was analyzed using complementary DNA amplified length polymorphism （cDNA-AFLP） technique. The infected 3-leaflet seedlings were followed for 48 h and root samples were taken at 0, 2, 10, 24 and 48 h after inoculation, respectively. A total of 12596 tran- script-derived fragments （TDFs） were amplified with 256 primer combinations, including 709 differential expressed TDFs, which were generated from 119 primer combinations. Ninety-eight TDFs were randomly chosen for DNA sequence analysis BLASTx analysis of the obtained sequences revealed that 40 TDFs encoded gene products associated with energy, tran-scription, signal transduction, defense, metabolism, cell growth, cell structure or/and protein synthesis. Analysis of the ex- pression of four genes by qRT-PCR verified the results from cDNA-AFLP. Strikingly, one of the identified TDFs, 32-54-1, occurred for 47 times in a known BW-resistant SSH library. These results suggest that resistance to BW in peanut involves multifaceted biochemical and physiological reactions, including regulation of the genes involved in different pathways, such as defense, singal transduction, metabolism, transcription and abiotic stresses. The TDF 32-54-1 was predicted to be closely related to BW resistance in peanut.