| Fusarium head blight(FHB)is one of the major wheat diseases caused by Fusarium species complex in the world,which leads to shriveled grain,grain weight reduction and yield loss.Deoxynivalenol(DON)is accumulated in grains after being infected with FHB.With the global warming and the change of cultivation and farming system,the occurrence area of the disease spread to the northwest,and the epidemic became more and more frequent,which seriously threatened the food security and food safety of our country.Developing and cultivating disease-resistant varieties,and combined with chemical prevention is one of the effective measures to control FHB at present.Selenium is not only an essential trace element for human beings,animals and other organisms,but also a beneficial element for plants.Selenium contributes to human immunity and plays an important role in protecting cardio-cerebrovascular and liver,anti-cancer and anti-aging.For plants,appropriate amount of selenium can not only promote plant development and increase yield,but also enhance plant resistance to stresses.In this paper,the inhibitory effects of different selenium forms on the FHB and the growth and toxin production of Fusarium graminearum were studied,and the in vitro and in vivo experiments were designed to analyze its regulation mechanism,so as to provide reference for the chemical control of FHB.The main results are as follows:(1)In vitro experiments showed that different forms of selenium inhibited the mycelial growth of Fusarium graminearum,and the effects varied with selenium forms,and all forms significantly inhibited the accumulation of DON toxin.(2)In planta experiments indicated that spraying organic selenium solution immediately after inoculation with FHB inhibited the spread of Fusarium graminearum within wheat ear and reduced the rate of diseased spikelets.Spraying SeMet and Se-YD1 significantly reduced the content of DON toxin when compared with the control,and the effect of Se-YD1 was the best,and the effect of SeMet was the second.(3)Fusarium graminearum was placed onto the media with pre-added Se-YDl at levels of 0,4 and 8 mg/L,respectively.After 3 days of culture,samples were collected for transcriptome analysis.Transcriptome sequencing indicated that 669 genes were differentially expressed over the three groups.GO analysis indicated that redox process,catalytic activity and inherent composition of the membrane were significantly enriched.A total of 246 pathways were significantly enriched by KEGG enrichment analysis.These differentially expressed genes were involved in microbial metabolism,biosynthesis of secondary metabolites and ABC transporters in different environments.(4)A total of 4599 proteins were identified by Label free quantitative proteomics,of which 25 were differentially accumulated over the three comparison groups.The functions of differentially accumulated proteins among the three groups were mainly catalytic activity,binding and transport activity.These differentially expressed proteins are mainly involved in important biological processes such as metabolic processes,cellular processes,biological regulation and cellular components,tissue or biogenesis.(5)The number of significantly differentially accumualted proteins and expressed genes associated with the three groups were 146,253 and 330 respectively.There are five different types of association between the transcripts and the abundance of protein.GO items significantly enriched in both groups are mainly oxidation-reduction process and catalytic activity.The KEGG pathways that were significantly enriched in both groups were mainly glyoxylic acid and dicarboxylic acid metabolism,starch and sucrose metabolism. |
