牡丹PsMYB43调控芳樟醇合成的功能解析OA

[Objective]The monoterpene substance linalool is an important component of the floral fragrance in tree peony(Paeonia suffruticosa'OuKan'),and MYB-type transcription factors play a crucial role in the synthesis of monoterpenes.Exploring the role of PsMYB43 in the synthesis of linalool in tree peony,aiming to provide genetic resources and theoretical basis for genetic improvement of floral fragrance.[Method]Using the P.suffruticosa'OuKan'as the experimental material,the CDS sequence of the PsMYB43 gene was first cloned,and its physicochemical properties,conserved structural domains,and phylogenetic relationships were analyzed using bioinformatics software.Secondly,RT-qPCR was used to analyze its expression patterns in different floral development stages and organ tissues.Subcellular localization was performed using tobacco,and finally the function of PsMYB43 was validated through transient overexpression and transient silencing to clarify its role in the synthesis of monoterpene compound linalool.[Result]The CDS sequence of PsMYB43 is 1 140 bp and encodes 379 amino acids.PsMYB43 is an unstable hydrophilic protein with two incomplete HTH domains,belonging to the R2R3-type MYB transcription factor family.Systematic evolutionary analysis revealed that the PsMYB43 protein in P.suffruticosa is most closely related to the PdMYB12L protein in P.delavayi.With flowering developing,the expressions first increased and then decreased,reaching its peak at the half-opening stage,consistent with the release pattern of linalool.PsMYB43 has the highest expressions in the outer petals during full blooming,while its expressions relatively low in carpels and stamens.Subcellular localization indicated that PsMYB43 is localized in the cell nuclear.Following transient overexpression of PsMYB43 in snapdragons,the levels of monoterpenes such as linalool,myrcene,and linalool significantly increases,rising by 2.0,1.67,and 3.4-fold,respectively.Following transient silencing of PsMYB43 in tree peony,linalool release decreases significantly by 38%.[Conclusion]PsMYB43 positively regulates the synthesis of monoterpenoid linalool in tree peony petals.