posted on 2021-03-08, 17:37authored byRu Wang, Sangram Keshari Lenka, Varun Kumar, Kelem Gashu, Noga Sikron-Persi, Irena Dynkin, David Weiss, Avichai Perl, Aaron Fait, Michal Oren-Shamir
Stilbenes are phytoalexins with health-promoting
benefits for humans.
Here, we boost stilbenes’ production, and in particular the
resveratrol dehydrodimer viniferin, with significant pharmacological
properties, by overexpressing stilbene synthase (STS) under unlimited phenylalanine (Phe) supply. Vitis vinifera cell cultures were co-transformed
with a feedback-insensitive E. coli DAHP synthase (AroG*) and STS genes,
under constitutive promoters. All transgenic lines had increased levels
of Phe and stilbenes (74-fold higher viniferin reaching 0.74 mg/g
DW). External Phe feeding of AroG* + STS lines caused a synergistic effect on resveratrol and viniferin accumulation,
achieving a 26-fold (1.33 mg/g DW) increase in resveratrol and a 620-fold
increase (6.2 mg/g DW) in viniferin, which to date is the highest
viniferin accumulation reported in plant cultures. We suggest that
this strategy of combining higher Phe availability and STS expression generates grape cell cultures as potential factories
for sustainable production of stilbenes with a minor effect on the
levels of flavonoids.