| Aroma is an important breeding objective trait of Anthurium andreanum,however,there are few studies on the genetic of aroma character.Therefore,it is of great importance to investigate floral fragrance compouds and genetics in order to create aroma Anthurium andreanum cultivar.In this paper,hybrid Offsprings of different combination in A.andreanum were used to study the main type of aroma and their separation regularities;AaDXS and AaDXR genes related to terpenoids synthesis were cloned from A.‘Mystral'and A.‘Alabama'and the bioinformatics were analyzed;The expression of genes involved in aroma was analyzed by using of qRT-PCR.The main results are as follow:1.12 germplasm resources of A.andreanum with aroma was employed to identify the type of aroma by the use of artificial sensory identification method.The result indicated that the fragrance of A.andreanum was divided into five categories including minty,pine,lemon,fruity and odor type,and the main type was pine type.2.Main fragrance compounds of lemon type,fruity type?,fruity type?and pine type?diploid and tetraploid?were D-limonene,benzyl acetate,isoamyl acetate and linalool,respectively,and the relative contents were 5.48?g·gFW-1·h-1,9.40?g·gFW-1·h-1,2.21?g·gFW-1·h-1,37.80?g·gFW-1·h-1?diploid?and 19.40?g·gFW-1·h-1?tetraploid?,respectively.In addition,there were benzyl acetate and euphyllol in pine type and fruit type of A.andreanum.3.AaDXS and AaDXR genes related to terpenoids synthesis were cloned from A.‘Mystral'with fragrance and A.‘Alabama'without fragrance.There were two transcript in AaDXR,the lengths of which were 2115bp and 1569bp,respectively,and encoded 704 and 522 amino acids.AaDXS ORF sequences of the two materials were basically the same,there was only one base difference at the first exon 1917 bp.C base in Mystral-AaDXS was replaced by T base in Alabama-AaDXS,however,the amino acid sequences were the same,therefore,the significant differential expression of the AaDXS gene in the scented and unscented parents was not caused by gene encoded sequences itself,but related to the transcriptional regulation.The encoded sequences length of AaDXR was 1413 bp,encoding 470 amino acids.AaDXR ORF sequences of the two materials were the same,except that there are one base difference at the second exon 27 bp.A base at the 27 bp in Mystral-AaDXR was substituded for T in Alabama-AaDXR,respectively,which resulted in lysine?K?at No.37 amino acid in Mystral-AaDXR replaced by methionine?M?in Alabama-AaDXR,and then causing one more Thr phosphorylation site in M-AaDXR.4.Compared with A.‘Alabama',DXS,DXR and PAL1 gene related to phenylaprapanoid metabolic pathway and DAHPS2 related to shikimic acid metabolic pathway,especial DXS?110-210 times?and PAL1 significantly highly expressed in spadix of A.‘Mystral',while DXS relative expression is the most highly in middle spadix of A.‘Mystral'.5.The expression of DXS,DXR,MCT,MDS and SES,especial DXS,in the stamen of scented hybrids was significantly higher than that in unscented ones.6.The expression PAL1,PAL2,MYBR2R3,MYB305 and DAHPS2,expecial PAL1and PAL2,were highly expressed in stamen of fruit type A.andreanum;The expression of DXS and SES were highly expressed in stamen of pine type A.andreanum.Through the above research,the compound,synthesis organ and pathway of amora were clarified,AaDXS and AaDXR genes related to terpenoids synthesis were cloned,and molecular genetic basis underlying aroma in Anthurium andreanum was preliminarily elucidated.These lay a foundation for further study molecular mechanism and molecular breeding of amora trait in Anthurium andreanum. |
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