The Analysis Of Physiological Response And Transcriptome Of Auricularia Cornea Under Tannin Stress

In this study,by setting different concentrations of tannin on the plate and liquid shake flask of Auricularia cornea,we determined the mycelial growth rate,mycelial dry weight,clamp connection hyphae ratio and mycelial branching frequency.Additionally,we conducted the transcriptome analysis of A.cornea and determined the effects of thiobarbituric acid reactive substances,catalase?CAT?,superoxide dismutase?SOD?,peroxidase?POD?and Fe³⁺on the mycelial growth rate.We elucidated the effects of tannin on the mycelia of A.cornea and clarified its preliminary mechanism.At the same time,this study provides new ideas for the use of coniferous sawdust to cultivate other types of edible fungi.The specific results are provided below:?1?By setting different concentrations of tannin on the plate and liquid shake flask of A.cornea,we determined the mycelial growth rate,mycelial dry weight,clamp connection hyphae ratio and mycelial branching frequency.We found that at a lower concentration?<0.01 g/L?,tannin promoted mycelial growth,but at higher concentration,it inhibited mycelial growth.In the shaking experiment,we found that mycelial dry weight decreased with an increased concentration of tannin?P<0.05?.?2?In the experiment for measuring the enzymatic activity of hypha under tannin stress,we found that tannin stress induced increased levels of lipid peroxidation in the mycelium cells with significant concentration and time effects.However,the activities of CAT,SOD and POD enzymes had different curves,thereby indicating that different antioxidant enzymes have different responses towards tannin stress.?3?With different concentrations of tannin and Fe³⁺ion concentration to determine the growth rate of A.cornea,we obtained three main findings:under low concentration,both tannin and Fe³⁺can promote mycelial growth.Tannin does not react with a low concentration of Fe³⁺;however,it will only react when the concentration of Fe³⁺exceeds a certain level.The reaction between tannin and Fe³⁺ion shall be an incomplete reaction.While forming a five-membered ring chelate,a small amount of tannin and Fe³⁺ions remained to promote mycelial growth.Additionally,there may be a redox reaction between tannin and Fe³⁺ions,that is,the reaction will generate a small amount of Fe²⁺ions and continue to promote mycelial growth.?4?Analysis results of A.cornea RNA-seq data.A total of 2012 DEGs?1117up-regulated,895 down-regulated?were identified between different concentrations of tannin and CK.The most differentially expressed genes underwent 0.2 g/L treatment,the least differentially expressed genes underwent 0.1 g/L treatment.The GO functional enrichment analysis showed that DEGs were enriched in 224 GO items.In summary,56 items were enriched in biological process,72 in cellular component and170 in molecular function.Among them,the significantly influenced items in biological functions were enriched in oxidoreductase activity,membrane part and iron ion binding,which were all associated with plant stress responses.The results of KEGG analysisshowed that the DEGs were specially enriched in biosynthesis of secondary metabolites,biosynthesis of antibiotics,carbon metabolism,biosynthesis of amino acids and protein processing in endoplasmic reticulum.The genes involved in different metabolic pathways provide important data support for further in-depth studies of A.cornea under tannins stress regulatory network.