Functional Analysis of PsMYB43 Regulating Linalool Synthesis in Tree Peony

doi:10.13560/j.cnki.biotech.bull.1985.2025-0832

Abstract

Abstract:

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.

Key words: Paeoniasuffruticosa, floral fragrance, MYB transcription factor, linalool, functional validation

WANG Zhen-quan, ZHONG Yi, MA Bo, WU Jing, HU Zeng-hui. Functional Analysis of PsMYB43 Regulating Linalool Synthesis in Tree Peony[J]. Biotechnology Bulletin, 2026, 42(4): 263-271.

Figures/Tables 8

Fig. 1 Seven different flower developmental stages and different organ tissues at full blooming in P. suffruticosa 'QuKan'

Table 1 Sequences of primers used in this study

引物名称 Primer name	引物序列 Primer sequence （5′‒3′）	作用 Function
PsMYB43-F	ATGGACTCTGTTCCGTCCAAG	基因克隆 Gene clone
PsMYB43-R	TCAAGAAAGAAGCCAAGCAAC	基因克隆 Gene clone
qPsMYB43-F	TTGACGGTGACTGGTAATG	实时荧光定量 RT-qPCR
qPsMYB43-R	CCAATCAATCCTTCCATCATC	实时荧光定量 RT-qPCR
yPsMYB43-F	ACCTCGACTCTAGAAATGGACTCTGTTCCGTCCAAGA	亚细胞定位 Subcellular localization
yPsMYB43-R	TTTTTCTACCGGTACAGAAAGAAGCCAAGCAACCATAG	亚细胞定位 Subcellular localization
gPsMYB43-F	ATGCCCGTCGACCCCATGGACTCTGTTCCGTCCAAGA	瞬时过表达 Transient overexpression
gPsMYB43-R	CCATGGATCCGGTACAGAAAGAAGCCAAGCAACCATAG	瞬时过表达 Transient overexpression
vPsMYB43-F	TGAGTAAGGTTACCGGAAGAGCTGGAAAATGGGATGTTAT	瞬时沉默 Transient silencing
vPsMYB43-R	GTGAGCTCGGTACCGCTTCCAAATCCCAATCAATCCTTC	瞬时沉默 Transient silencing
PsACTIN-F	GCGTTGACGACTTTCTCATCCT	牡丹荧光定量内参 Internal reference gene of tree peony
PsACTIN-R	CGCACATCCTTGACAAACCCTA	牡丹荧光定量内参 Internal reference gene of tree peony
AmUBI-F	GACCTATACCAAGCCGAAG	金鱼草荧光定量内参 Internal reference gene of snapdragon
AmUBI-R	CGTTCCAGCACCACAATC	金鱼草荧光定量内参 Internal reference gene of snapdragon

Fig. 2 Sequence alignment analysis of PsMYB43 with homologous proteinsDark blue: Homology 100%. Red: Homology≥75%. Blue: Homology≥50%

Fig. 3 Phylogenetic analysis of PsMYB43The number on the branch are the bootstrap value (%)

Fig. 4 Expression patterns of PsMYB43 geneA: Relative expressions of PsMYB43 during seven flower development stages. B: Relative expressions of PsMYB43 in eight different organs and tissues during full blooming stage. Different lowercase letters indicate significant differences at P<0.05 level

Fig. 5 Subcellular localization of PsMYB43 in P. suffruticosa

Fig. 6 Detection of the expression of overexpressed PsMYB43, its effect on different monoterpene substances, and GC-MS analysisA: PsMYB43 gene expression. B: Release of monoterpenoid substances. C: GC-MS analysis of VOCS. ns P>0.5, ** P<0.01, *** P<0.001, and **** P<0.000 1, the same below

Fig. 7 Detection of silencing PsMYB43 expression (A) and its effect on linalool (B)

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