Purine and pyrimidine dinucleoside polyphosphates differentially affect the phenylpropanoid pathway in Vitis vinifera L. cv. Monastrell suspension cultured cells.

It is known that the concentration of dinucleoside polyphosphates (NpN's) in cells increases under stress and that adverse environmental factors induce biosynthesis of phenylpropanoids, which protect the plant against stress. Previously, we showed that purine NpN's such as ApA and ApA induce both the activity of enzymes of the phenylpropanoid pathway and the expression of relevant genes in Arabidopsis seedlings. Moreover, we showed that ApA induced stilbene biosynthesis in Vitis vinifera cv. Monastrell suspension cultured cells. Data presented in this paper show that pyrimidine-containing NpN's also modify the biosynthesis of stilbenes, affecting the transcript level of genes encoding key enzymes of the phenylpropanoid pathway and of these, UpU caused the most effective accumulation of trans-resveratrol in the culture media. Similar effect was caused by ApA and GpG. Other pyrimidine NpN's, such as CpC, CpC, and ApC, strongly inhibited the biosynthesis of stilbenes, but markedly (6- to 8-fold) induced the expression of the cinnamoyl-CoA reductase gene that controls lignin biosynthesis. Purine counterparts also clearly induced biosynthesis of trans-resveratrol and trans-piceid, but only slightly induced the expression of genes involved in lignin biosynthesis. In cells, UpU caused a greater accumulation of trans-resveratrol and trans-piceid than did UpU. Each of the NpN's studied induced expression of the gene encoding the resveratrol transporter VvABCG44, which operates within the Vitis vinifera cell membrane. AMP, GMP, UMP, and CMP, potential products of NpN degradation, did not affect the accumulation of stilbenes. The results obtained strongly support that NpN's play a role as signaling molecules in plants.