Comparison Of Selenium Enrichment Capacity And Preliminary Exploration Of Mechanism Of Six Legume Sprouts

Selenium is an essential trace element that functions in the body in the form of selenoproteins and has important physiological functions.At the same time,selenium is also a beneficial element for plant growth,which can promote plant growth,improve the level of photosynthesis in plants,and enhance the content of biologically active substances.Legumes are important food crops and oil crops in China,rich in resources,and rich in protein,fiber,carbohydrates,vitamins,minerals,etc.,with great nutritional value.Legumes have strong selenium-rich ability,and the seeds of legumes are cultivated into selenium-rich sprouts by hydroponics,which can be developed into highly efficient selenium supplement products for improving the health of selenium-deficient populations.In order to screen out the optimal source of plant selenoprotein and selenium-rich conditions,the seeds of six legumes of pea,soybean,mung bean,kidney bean,broad bean and black bean were selected,and the exorganic inorganic selenium(sodium selenite)was absorbed by soaking the seeds,and the germination was made by hydroponics.By determining the selenium content and protein content in the sprouts,combined with germination rate and organic selenium ratio,the best selenium-rich varieties among the six legumes were screened,as well as the best selenium-rich concentration and the best selenium-rich growth stage of the cultivars.Subsequently,according to the best results of the above screening,selenium-rich sprouts treated with three sodium selenite concentrations of0,20 mg/kg and 80 mg/kg were taken,the leaves and roots were separated,the selenium morphology and content were determined and the transcriptomic sequencing(RNA-Seq)was analyzed,and the selenium polyselene mechanism of the sprouts was elucidated in combination with physiological indicators and gene expression.The main findings are as follows:1.Different varieties have different tolerance to selenium.The germination rate of kidney bean and broad bean is the lowest in selenium solution.The selenium enrichment ability of soybean and black bean was significantly lower than that of mung bean and pea.According to the comparison of organic selenium ratio and protein content,it was found that mung bean had a slight advantage over pea.Finally,mung bean was selected as the best selenium-enriched variety for subsequent experiments.At 10 concentrations,the germination rate of mung bean reached the highest 86% at 80 mg/kg.The content of total selenium and organic selenium increased with the increase of sodium selenite concentration,and there were significant differences between every two adjacent concentration gradients except 20 and 30 mg/kg,50 and 60 mg/kg,80 mg /kg,the proportion of organic selenium reached the highest,and combined with the comparison of protein content,80 mg/kg was selected as the optimal selenium-enriched concentration and subsequent experiments were carried out.In the selection of the best growth stage,the indicators within 1-8 days were compared.The germination rate increased within 1-4 days and became stable on the 4th day.Both total selenium and organic selenium reached the highest on the 3rd day,while the proportion of organic selenium reached the highest on the 5th day.5 days is the best selenium-rich growth stage.To sum up,among the six leguminous plants,the best selenium-enriched variety was mung bean,the optimum selenium-enriched concentration was 80 mg/kg,and the optimum selenium-enriched growth stage was 5 days.2.In the leaves and roots of the control group,only two forms of selenium,Se(Ⅳ)and Se(VI),were detected,while five forms of selenium were detected in the leaves and roots of the Na2 Se O3 treatment group.At the three concentrations,the selenium content in the leaves of mung bean sprouts was higher than that in the roots,indicating that the mung bean sprouts cultivated by soaking and hydroponics were mainly enriched in selenium in the leaves.Practicable.3.The differentially expressed genes and metabolic pathways of 18 samples under three concentrations of leaves and roots were analyzed by transcriptome sequencing.9401(5001 up-regulated,4400 down-regulated)and 7554(3820up-regulated,3734 down-regulated)differentially expressed genes were identified in leaves and roots,respectively.The enrichment analysis of the differential genes showed that the differential genes were mainly enriched in carbohydrate metabolism,lipid metabolism,amino acid metabolism,secondary metabolism and genetic information processing.4.WGCNA analysis was performed on the selenium speciation and transcriptomic data,the co-expressed gene clusters were dynamically cut,and 24 modules were generated after merging similar clusters,and darkgreen,yellow and black were screened out.The related modules were analyzed by GO and KEGG enrichment.The top 30 connected genes in the three modules were constructed as gene expression networks,and network visualization analysis was performed,and 12 keys related to selenium metabolism were screened out.gene,and verified it by q PCR,which finally proved the reliability of the transcriptome data.