Afifi Maha, El-Kereamy Ashraf, Legrand Valérie, Chervin Christian, Monje Marie-Carmen, Nepveu Françoise, Roustan Jean-Paul
Institut National Polytechnique, Ecole Nationale Supérieure Agronomique de Toulouse, UMR INRA/INP-ENSAT 990, BP 107, F-31326 Castanet Tolosan cedex, France.
J Plant Physiol. 2003 Aug;160(8):971-5. doi: 10.1078/0176-1617-00921.
Eutypine, 4-hydroxy-3-(3-methyl-3-butene-1-ynyl) benzaldehyde, is a toxin produced by Eutypa lata, the causal agent of Eutypa dieback in grapevine. The effect of the toxin on anthocyanin synthesis has been investigated in Vitis vinifera cv. Gamay cell cultures. At concentrations higher than 200 micromol/L, eutypine reduced anthocyanin accumulation in cells. The reduction in anthocyanin accumulation was proportional to the eutypine concentrations and HPLC analysis showed that eutypine affected the levels of all anthocyanins. The effect of eutypine application on the expression of five genes of the anthocyanin biosynthesis pathway, including chalcone synthase (CHS), flavonone-3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), leucoanthocyanidin dioxygenase (LDOX), and UDP glucose-flavonoid 3-O-glucosyl transferase (UFGT) was determined. Expression of CHS, F3H, DFR and LDOXwas not affected by the addition of eutypine to grapevine cell cultures. In contrast, expression of the UFGT gene was dramatically inhibited by the toxin. These results suggest that in grapevine cell cultures, eutypine strongly affects anthocyanin accumulation by inhibiting UFGT gene expression. The mechanism of action of eutypine is discussed.
刺盘孢菌素，即4-羟基-3-(3-甲基-3-丁烯-1-炔基)苯甲醛，是由葡萄藤上引起葡萄藤溃疡病的病原菌——葡萄座腔菌产生的一种毒素。已在酿酒葡萄品种佳美细胞培养物中研究了该毒素对花青素合成的影响。在浓度高于200微摩尔/升时，刺盘孢菌素会降低细胞中花青素的积累。花青素积累的减少与刺盘孢菌素浓度成正比，高效液相色谱分析表明，刺盘孢菌素影响所有花青素的水平。测定了施用刺盘孢菌素对花青素生物合成途径中五个基因表达的影响，这五个基因包括查尔酮合酶（CHS）、黄酮醇-3-羟化酶（F3H）、二氢黄酮醇4-还原酶（DFR）、无色花青素双加氧酶（LDOX）和UDP-葡萄糖-类黄酮3-O-葡萄糖基转移酶（UFGT）。向葡萄细胞培养物中添加刺盘孢菌素不会影响CHS、F3H、DFR和LDOX的表达。相反，毒素会显著抑制UFGT基因的表达。这些结果表明，在葡萄细胞培养物中，刺盘孢菌素通过抑制UFGT基因表达强烈影响花青素的积累。本文还讨论了刺盘孢菌素的作用机制。
