| The outbreak of algal blooms not only lead to the asphyxiation of the fish and affect the tourist industries,but also release highly toxic compounds–microcystins,threatening the health of human beings and other organisms.Compared to the physical and chemical methods for control algal blooms,biological methods are simpler and less pollution,and become hot spot.Although algicidal bacteria,viruses,fungi can inhibite the growth of algae,they also affect the clarity of water and the aquatic ecosystem.In recent years,a new removal of cyanobacteria fungus-Trichaptum abietinum 1302 BG was discovered.Mycelia of the fungus can wrap algal cells and completely degrade the co-cultivated algal cells,resulting the clarification of the algae solutions.This novel method of control algae via fungal mecylia which can overcome the disadvantages of the previous biological methods and provide a new method for inhibiting algal blooms.However,the molecular mechanism of removal algae is not clear.In this study,Bjerkandera adusta T1 was used as tested strain to investigate the mechanism of this new fungus-algae interaction by transcriptome analyses.Differently expressed genes(DEG)of the fungus during co-culture with algae were further used in GO analysis,KEGG enrichment analysis,and principal component analysis.Several decomposition enzyme genes were verified by Real-time PCR.The major decomposition enzyme genes of Trametes versicolor F21 a and B.adusta T1 in the process of degradation algal cells were compared in the end.The main results are as follows:1.The fungal mycelia during co-cultivated with algal cell for 0 h,6 h,12 h,24 h,and 48 h were sampled for transcriptome sequence,and each sample had two biological repeats.77%-80% of clean reads can be mapped to B.adusta T1 reference genome.753,862,1058,1243 genes were up-regulated during the co-cultural processes compared to 0 h,while 753,862,1058,1243 genes were down-regulated.2.GO term enrichment analyses show that the DEG was mainly related to lyase activity,transporter activity,etc.at molecular function level.At cellular component level,the DEG was mainly associated with microbody,peroxisome,etc.At molecular function level,the DEG was primarily related to cellular process,metabolic process,etc.KEGG pathway enrichment analyses indicate that the DEG was mainly related to Metabolism and Genetic information processing.The DEG was involved in Proteasome,Carbon metabolism,Mino sugar and nucleotide sugar metabolism and Biosynthesis of amino acids.GO and KEGG enrichment analysis suggested that the fungus B.adusta T1 probably first decompose the algal cells,and then transport the metabolites into its own cell as raw materials for fungal growth and development.Decomposition enzymes of B.adusta T1 might play a major role in removal algal cells.Correlation and principal component analysis implying that decomposition enzymes of B.adusta T1,such as jgi.p | Bjead | 306404(AA2),jgi.p | Bjead | 43095(AA2),jgi.p | Bjead | 34945(GH18),jgi.p | Bjead | 34577(GH17),etc.might play a major role in removal algal cells.3.Several up-regulated decomposition enzymes genes were further verified by Real-time PCR.Results of Real-time PCR were similar to that of transcriptome analyses,indicated that the RNA-seq results were reliable.4.Compared with the decomposition enzymes which played a major role during degradation algea between T.versicolor F21 a and that of B.adusta T1,we could infer that GH17,GH18 gene families both in T.versicolor F21 a and B.adusta T1 play important role in algicidal processes.In this paper,different techniques were used to study molecular mechanism of B.adusta T1 in efficiently eliminating algal cells.Major decomposition enzyme genes of B.adusta T1 was preliminarily identified and elucidate the biochemical basis during the algicidal processes.The results of this study not only enrich the understanding of mechanism in eliminating living algal cells,but also provide theoretical guidance for generate more efficient algicidal fungus. |
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