| Astragalus membranceus Bge.var.mongolicus(Bge.)Hsiao,a perennial herb of Astragalus leguminosae,is an important medicinal plant.In recent years,wild A.mongolicus is on the verge of extinction,mainly from artificial cultivation.However,because of hard seed coat and dormancy,there are problems such as difficulty in germination and irregular emergence.In this paper,the effects of negative corona electric field on the seed vigor of A.mongolicus in Dao-di of Inner Mongolia were studied.The number and duration of treatment were gradually increased to analyze the antioxidant enzyme activity and active oxygen content of seedlings;the molecular mechanism of A.mongolicus dose response to different negative corona electric field treatment was studied in combination with transcripts.The relevant results are as follows:1.A.mongolicus was treated with-3 kV—-7 kV for 30,60 and 90 min,respectively.The results of seed vigor determination showed that under the treatment of-7 kV for 90 min,the MDA content of seedlings was significantly lower than that of the control,the electrical conductivity and apparent contact angle of seeds were significantly lower than those of the control,and the water absorption rate was significantly higher than that of the control.There was no malignant damage in the epidermis observed by scanning electron microscopy.It indicated that appropriate negative corona electric field treatment could effectively reduce lipid membrane peroxidation,enhance the repair ability of membrane system,and improve seed vigor.2.A.mongolicus seeds were treated with-7 kV for 90 min for 1-6 times.The results showed that under single treatment,the changes of each index were not significantly different from those of the control group.After 6 treatments,the enzyme activities of superoxide dismutase and peroxidase were increased by 88% and 31%,respectively,and the catalase activity was 3.81 times that of the control group.The rest deals with the above indicators have an upward trend and a downward trend.Transcriptome sequencing was performed once and six times.3.1134 differentially expressed genes were identified by transcriptome in single treatments,including 368 up-regulated and 766 down-regulated genes.A total of 22791 genes were identified in accumulated treatments,including 15082 up-regulated and 7709 down-regulated genes.Venn and volcano Plot found that 694 genes were differentially expressed between the two groups,and the total number of differentially expressed genes in cumulative treatment was about 20 times that in single treatment and was more indigenous.4.According to the functional annotation and enrichment results of differentially expressed genes,many differentially expressed genes were enriched to regulate plant growth and development in both single and cumulative treatments.GO database annotation found that the two groups of differential genes were functionally similar,but the number of cumulative genes processed was several times or tens of times that of the single group;KEGG enrichment showed that 108 pathways were enriched in a single treatment,and 1 pathway was significantly enriched(Q < 0.05).The accumulated differential genes were enriched to 136 pathways,and 16 were significantly enriched.The expression levels of 9 genes were determined by RT-q PCR to verify the reliability of transcriptome data.In conclusion,this study selected a single treatment dose based on the effect of negative corona electric field on seed vigor.After accumulating many times,screening criteria based on physiological and biochemical indexes of seedlings,transcriptome sequencing was used to explore the effect of cumulative effect on plant growth and development characteristics and molecular mechanism,which confirmed that the cumulative effect was a better mutagenic dose. |
PDF Full Text Request