| Dendrobium nobile is a perennial herbaceous epiphytic orchid Dendrobium,which has many pharmacological effects including immune reg?lation,anti-tum or,anti-oxidation,hypoglycemia and bacteriostasis.Dendrobium nobile is a rare traditional Chinese medicine,which is known as the first nine magic herb.M odern pharmacological studies indicated that the alkaloid of Dendrobium nobile stem has certain curative effect on cataract,cardiovasc?lar and gastrointestinal diseases.The production of Dendrobium nobile Lind1.in Chishui account 70% of the total.In practice,the content of Dendrobine are different greatly in diff erent ecological environment,different growth,different year and different harv est time.The content of Dendrobine of different growth stage are significant di fference,too.In order to ensure orderly in development of Dendrobium nobile Lind1.and obtain the stable and controllable content of Dendrobine,how to pro duce,operate,accum?late and c?lture,these urgent to solve the Dendrobine m etabolism mechanisms.The metabolic pathways of is not known,so the researc h on metabolic reg?lation are little.Consequently,the growth period of Dendrobium nobile Lind1.as experimen tal material,dry matter accum?lation and distribution of Dendrobium nobile,ac cum?lation and distribution characteristics of Dendrobium will be studied.The study found that there was a relationship between Dendrobium conten t and the different developmental stages.Stem of the 4 period of Dendrobium nobile was taken as a sample,which were significant differences in the content of Dendrobium.Four Differential Gene Expression profiles were analyzed with comparison of Transcriptional Library.The number,function and expression p attern of differentially-expressed genes(DEGs)will be analyzed and compare d,systematically screened Dendrobine-related genes.The transcriptome and digi tal gene expression profiling analyses of Dendrobium nobile will be conducted during the Dendrobine using the RNA-Seq technology.The pathway of Dendrobium biosynthesis was discussed,which was Terpenoid biosynthesis.All of the transcript information of will be revealed.(1)There was a relationship between Dendrobium content and the differe nt developmental stages.The increases of Dendrobium content in annual stems and leaves were in March-June,October-December and March-June,SeptemberDecember.Biennial were in April-June,October-December and February-June,September-December.The increases of Dendrobium content and germination-gro wth of new bud were identical in time.(2)Dendrobium content was high in young tender tissue.Dendrobium co ntent in annual stems kept growing faster from 0.22% in March to 0.97% in J une.Dendrobium growth in unit dry matter was 10.47mg/g in April-May.Den drobium content in biennial stems kept growing from 0.33% in April to 0.43%in June.Dendrobium content in annual stems was more than 2 times as muc h as biennial in June.(3)Dendrobium had a movable property.Dendrobium accum?lation in bi ennial stems was “reducing—rising—reducing—rising” und?latory property.The reductions of Dendrobium content in biennial stems were formation and germin ation of new buds.The increases of Dendrobium content were moved from yo ung tender tissue and before defoliation.Dendrobium was transferred to young tissue.Dendrobium were moved from young tender tissue(growing points)or storage organs.(4)The annual dry matter and Dendrobium accum?lation were very diffe rent from the biennial.The dry weight of plant showed "S" curve change.Log istic equation was fitted successf?lly by the dry matter accum?lation of annual plant.The dry matter distribution rate of the leaves of annuals was higher than that of stem before August,but opposite after August.The amount of biennia l dry matter accum?lation decreased in general.The accum?lation of dry matte r in stem changed a little.The annual undertake vegetative growth,and the bi ennial assumed vegetative propagation.The change range of Dendrobium conte nt in annual stems was wide from 0.22% to 0.97%.Dendrobium accum?lation of stems showed " fast-slow-fast " growth trend.The distribution of dendr obine of stems was always larger than that of leaves.In January and Decembe r,there was little difference in the content and accum?lation of dendrobine.De ndrobine distribution rate of stems was higher than that of leaves.The relation ship of dry matter accum?lation and dendrobine accum?lation was extremely si gnificant positive correlation of the annual plants,stems and leaves.(5)The transcriptional Library of Dendrobium nobile was constructed.79,436 Unigenes were obtained,which mean length was 780 nt.A total of 55,393(69.73%)Unigenes were annotated using public six protein databases of Nr,Nt,Swiss Port,KEGG,COG and GO.30,061 Unigenes were enriched to 128 Kyoto Encyclopedia of Genes and Genomes pathways.426 Unigenes were ann otated to Terpenoid backbone biosynthesis(KO00900).28 Unigenes were ann otated to Sesquiterpenoid and Triterpenoid biosynthesis(KO00909).(6)The Gene Expression Profiling Library of Dendrobium nobile was co nstructed,which was 4 periods of differences in the content of Dendrobium.D GE was analyzed comparing with transcriptome.DGEs were 2482?2332 and 1487 between Jun-10 and Oct-10,Sep-10,Aug-10,respectively,which All dow n-reg?lated genes were larger than up-reg?lated genes.The number of DEG in Aug.10-VS-Sep.10,Aug.10-VS-Oct.10,Sep.10-VS-Oct.10 was 1,361,1,614 a nd 1,619,respectively,which All up-reg?lated genes were larger than down-reg?lated genes.Expression pattern clustering,GO and KEGG were analyzed.17 Unigenes were annotated to Terpenoid backbone biosynthesis.2 Unigenes were annotated to Sesquiterpenoid and Triterpenoid biosynthesis.(7)5 genes involved in the metabolism of Dendrobium were screened,w hich were Mevalolate kinase gene(Unigene1219),Lysine methylation gene(C L429),isopentenyl diphosphate isomerase gene(CL3435),Farnesyl transferas e gene(CL11407)and Cysteine methyl esterase gene(CL8067),respectively.The expression level of RNA-Seq differentially expressed genes was verified b y quantitative real-time PCR expression.It was found that the changes in the DEGs expression measured by the two methods were similar.The square R2 of correlation coefficient was 0.4666,and the correlation reached a very signific ant level,which indicated great reproducibility between transcript abundance ass ayed by RNA-Seq and the expression profile revealed by q-PCR data.The pathway of Dendrobium biosynthesis was the common pathway of ter pene formation to monoterpene(MVA and MEP),then sesquiterpene biosynth esis.Basic physiological processes of growth were studied,which were Dendrob ium content,Dendrobium accum?lation and dry matter accum?lation.The time and location of the difference in the content of Dendrobium were found.Dend robium metabolism was studied by transcriptional and digital gene expression p rofiles.The pathway of Dendrobium biosynthesis was terpenoid pathway.All o f the transcript information of will be revealed.The direction of Dendrobium b iosynthesis was pointed out.The study platform was provided to other Terpeno id alkaloids and other secondary metabolites. |
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