【作者】 安逸民； 宋丽莉； 刘英蕊； 郭长虹；

【Author】 Yi-Min An;Li-Li Song;Ying-Rui Liu;Chang-Hong Guo;Harbin Normal University;

【机构】 哈尔滨师范大学；

【摘要】 盐碱胁迫在世界范围内对农业生产造成了广泛的影响。紫花苜蓿是一种豆科多年生牧草,在世界范围内广泛种植,一些地方品种对盐和盐碱胁迫具有一定的抗性。为了探索植物对盐碱胁迫的耐受机制,本研究对紫花苜蓿幼苗进行了盐碱胁迫下0天,1天和7天的转录组测序分析。在测序结果中,共获得了53,853个unigene,其中在1天和7天处理下,分别存在2,286和2,233个显著差异表达基因,主要富集于14个GO标签中,初步揭示了植物在短期和长期胁迫应答中的响应通路,包括活性氧代谢,类黄酮代谢,光通路等。其中,109个和96个转录因子分别在1天和7天处理下显著改变了表达模式。相对于盐胁迫响应的数据,本研究筛选了18个在盐和盐碱胁迫下响应存在差异的基因,包括NAC基因,醛酮还原酶,GST等基因,同时通过对植物胁迫下ROS,MDA和叶绿素含量等的生理测定发现,相对盐胁迫,植物抗氧化通路和脱毒通路在盐碱胁迫下十分活跃,可能对植物耐盐碱机制具有重要作用。综上所述,本研究对紫花苜蓿耐盐碱机制的探索提供一个新的视角。更多还原

【Abstract】 Saline-alkaline stress, caused by high levels of harmful carbonate salts and high soil pH, is a major abiotic stress that affects crop productivity. Alfalfa is a widely cultivated perennial forage legume with some tolerance to biotic and abiotic stresses, especially to saline-alkaline stress. To elucidate the mechanism underlying plant saline-alkaline tolerance, we conducted transcriptome analysis of whole alfalfa seedlings treated with saline-alkaline solutions for 0 d(control), 1 d(short-term treatment), and 7 d(long-term treatment) using ion torrent sequencing technology. A transcriptome database dataset of 53,853 unigenes was generated, and 2,286 and 2,233 genes were differentially expressed in the short-term and long-term treatment, respectively. Gene ontology analysis revealed 14 highly enriched pathways and demonstrated the differential response of metabolic pathways between the short-term and long-term treatment. The expression levels of 109 and 96 transcription factors were significantly altered significantly after 1 d and 7 d of treatment, respectively. Specific responses of peroxidase, flavonoids, and the light pathway component indicated that the antioxidant capacity was one of the central mechanisms of saline-alkaline stress tolerance response in alfalfa. Among the 18 differentially expressed genes examined by real time PCR, the expression levels of eight genes, including inositol transporter, DNA binding protein, raffinose synthase, ferritin, aldo/keto reductase, glutathione S-transferase, xyloglucan endotrans glucosylase, and a NAC transcription factor, exhibited different patterns in response to saline and alkaline stress. The expression levels of the NAC transcription factor and glutathione S-transferase were altered significantly under saline stress and saline-alkaline stress; they were upregulated under saline-alkaline stress and downregulated under salt stress. Physiology assays showed an increased concentration of ROS and MDA and a decreased content of chlorophyll, indicating that anti-oxidation and detoxification play an important role in response to saline-alkaline stress. Overall, the transcriptome analysis provided novel insights into the saline-alkaline stress tolerance response mechanisms in alfalfa.更多还原