Research Centre, Agriculture Canada, London, Ontario, N6G 2V4, Canada.
Plant Physiol. 1989 Sep;91(1):23-7. doi: 10.1104/pp.91.1.23.
Etiolated hypocotyls of the resistant soybean (Glycine max [L.] Merr.) cultivar Harosoy 63 became susceptible to Phytophthora megasperma (Drechs.) f.sp. glycinea (Hildeb.) Kuan and Erwin race 1 after treatment with abscisic acid. Susceptibility was expressed by increases in lesion size and a major decrease in accumulation of the isoflavonoid phytoalexin, glyceollin. In untreated hypocotyls, activity of phenylalanine ammonia-lyase and accumulation of mRNA for this enzyme increased rapidly after infection, but these increases were suppressed in abscisic acid-treated hypocotyls. The results suggest the possibility that biosynthesis of glyceollin in the resistance response of soybeans may be controlled at the transcriptional level by changes in abscisic acid concentrations caused by infection.
经脱落酸处理后，耐草甘膦大豆（Glycine max [L.] Merr.）品种 Harosoy 63 的黄化下胚轴对大豆疫霉（Phytophthora megasperma （Drechs.） f.sp. glycinea （Hildeb.） Kuan 和 Erwin 小种 1）变得敏感。易感性表现为病变大小增加，异黄酮类植物抗毒素glyceollin 的积累大量减少。在未处理的下胚轴中，苯丙氨酸解氨酶的活性和该酶的 mRNA 积累在感染后迅速增加，但在脱落酸处理的下胚轴中这些增加被抑制。结果表明，大豆抗性反应中 glyceollin 的生物合成可能在转录水平上受到感染引起的脱落酸浓度变化的控制。
