Veratrole Biosynthesis in White Campion    

Abstract

White campion (Silene latifolia) is a dioecious plant that emits 1,2-dimethoxybenzene (veratrole), a potent pollinator attractant to the nocturnal moth Hadena bicruris. Little is known about veratrole biosynthesis, although methylation of 2-methoxyphenol (guaiacol), another volatile emitted from white campion flowers, has been proposed. Here, we explore the biosynthetic route to veratrole. Feeding white campion flowers with [ 13 C 9 ]L-phenylalanine increased guaiacol and veratrole emission, and a significant portion of these volatile molecules contained the stable isotope. When white campion flowers were treated with the phenylalanine ammonia lyase inhibitor 2-aminoindan-2-phosphonic acid, guaiacol and veratrole levels were reduced by 50% and 63%, respectively. Feeding with benzoic acid (BA) or salicylic acid (SA) increased veratrole emission 2-fold, while [ 2 H 5 ]BA and [ 2 H 6 ]SA feeding indicated that the benzene ring of both guaiacol and veratrole is derived from BA via SA. We further report guaiacol O-methyltransferase (GOMT) activity in the flowers of white campion. The enzyme was purified to apparent homogeneity, and the peptide sequence matched that encoded by a recently identified complementary DNA (SlGOMT1) from a white campion flower expressed sequence tag database. Screening of a small population of North American white campion plants for floral volatile emission revealed that not all plants emitted veratrole or possessed GOMT activity, and SlGOMT1 expression was only observed in veratrole emitters. Collectively these data suggest that veratrole is derived by the methylation of guaiacol, which itself originates from phenylalanine via BA and SA, and therefore implies a novel branch point of the general phenylpropanoid pathway.

Floral volatiles: from biosynthesis to function

“…O ‐methyltransferases were shown to be responsible for the synthesis of a diverse array of benzenoids/phenylpropanoids, including veratrole in Silene flowers (Gupta et al . ; Akhtar & Pichersky ), 3,5‐dimethoxytoluene and 1,3,5‐trimethoxybenzene in roses (Lavid et al . ; Scalliet et al .…”

Biosynthetic and Functional Color–Scent Associations in Flowers of Papaver nudicaule and Their Impact on Pollinators

“…These compounds are known to act as pollinator attractants in a number of species . Although their biosynthesis is not well studied, some reports suggest that they are products of the phenylpropanoid biosynthetic pathway . In P. nudicaule , this route is active during the production of pelargonidin, thus suggesting a second biochemical connection between floral volatiles and pigments in the flowers of this species.…”

Substituted Pyrazolo[3,4-B]Pyridin-3-Ones and Pyrazolo[3,4-B]Pyridine-5- Carbaldehyde, New One-Pot Synthesis Strategy Amelioration Using Vinamidinium Salts, Antibacterial and Antifungal Activities Promising Environmental Protection

“…A previous study showed that 1,2-dimethoxybenzene (veratrole) is a potent pollinator attractant to the nocturnal moth Hadena bicruris emited by white campion (Silene latifolia: a dioecious plant). Akhtar et al [44] explored firstly the biosynthetic route to veratrole. Then, suggested that it was derived by the methylation of guaiacol (2-methoxyphenol), which itself originates from phenylalanine via BA (benzoic acid) and SA (salicylic acid), and therefore implies a novel branch point of the general phenylpropanoid pathway.…”