Tomato glycosyltransferase Twi1 plays a role in flavonoid glycosylation and defence against virus

Abstract

Background: Secondary metabolites play an important role in the plant defensive response. They are produced as a defence mechanism against biotic stress by providing plants with antimicrobial and antioxidant weapons. In higher plants, the majority of secondary metabolites accumulate as glycoconjugates. Glycosylation is one of the commonest modifications of secondary metabolites, and is carried out by enzymes called glycosyltransferases. Results: Here we provide evidence that the previously described tomato wound and pathogen-induced glycosyltransferase Twi1 displays in vitro activity toward the coumarins scopoletin, umbelliferone and esculetin, and the flavonoids quercetin and kaempferol, by uncovering a new role of this gene in plant glycosylation. To test its activity in vivo, Twi1-silenced transgenic tomato plants were generated and infected with Tomato spotted wilt virus. The Twi1-silenced plants showed a differential accumulation of Twi1 substrates and enhanced susceptibility to the virus. Conclusions: Biochemical in vitro assays and transgenic plants generation proved to be useful strategies to assign a role of tomato Twi1 in the plant defence response. Twi1 glycosyltransferase showed to regulate quercetin and kaempferol levels in tomato plants, affecting plant resistance to viral infection.

The phenylpropanoid pathway inhibitor piperonylic acid induces broad‐spectrum pest and disease resistance in plants

“…(c) Amount of lignin as determined through the acetyl bromide method (expressed as % of total dry cell wall mass). 'ns' (not significant) indicates no differences between treatments in a tissue; where significant differences between treatments exist, letters are used to indicate which treatments differ significantly (p < .05; N = 15) [Colour figure can be viewed at wileyonlinelibrary.com] flavonoids and coumarins (Campos et al, 2019). Twi1 silencing perturbs flavonoid metabolism and increases susceptibility to tomato spotted wilt virus (Campos et al, 2019).…”

“…'ns' (not significant) indicates no differences between treatments in a tissue; where significant differences between treatments exist, letters are used to indicate which treatments differ significantly (p < .05; N = 15) [Colour figure can be viewed at wileyonlinelibrary.com] flavonoids and coumarins (Campos et al, 2019). Twi1 silencing perturbs flavonoid metabolism and increases susceptibility to tomato spotted wilt virus (Campos et al, 2019). Although Twi1 is SA-inducible, the continued ability of elicitors to induce Twi1 in tomato plants expressing the NahG construct suggests the existence of SAindependent Twi1 regulation (O'Donnell et al, 1998).…”