Identification of white campion ( Silene latifolia ) guaiacol O -methyltransferase involved in the biosynthesis of veratrole, a key volatile for pollinator attraction

摘要: Silene latifolia and its pollinator, the noctuid moth Hadena bicruris, represent an open nursery pollination system wherein floral volatiles, especially veratrole (1, 2-dimethoxybenzene), lilac aldehydes, phenylacetaldehyde are of key importance for signaling. Despite important role scent in ensuring reproductive success S. latifolia, molecular basis biosynthesis this species has not yet been investigated. We isolated two full-length cDNAs from that show similarity to rose orcinol O-methyltransferase. Biochemical analysis showed both guaiacol O-methyltransferase1 (SlGOMT1) & O-methyltransferase2 (SlGOMT2) encode proteins catalyze methylation form veratrole. A large Km value difference between SlGOMT1 (~10 μM) SlGOMT2 (~501 resulted is 31-fold more catalytically efficient than SlGOMT2. qRT-PCR expression SlGOMT genes specifically expressed flowers male had 3- 4-folds higher level GOMT gene transcripts female flower tissues. Two related cDNAs, dioica (SdOMT1) (SdOMT2), were also obtained sister dioica, but they did methylate guaiacol, consistent with lack emission species. Our evolutionary uncovered evolved under positive selection, whereas SdOMT1 SdOMT2 no evidence selection. Altogether, we report identification functional characterization gene, efficiently catalyzes formation, another copy only one amino acid difference, was found be less synthesis latifolia.