Miller K. J., Hadley J. A., Gustine D. L.
Graduate Programs in Genetics (K.J.M.) and Plant Physiology (K.J.M., D.L.G.), Departments of Food Science (K.J.M., J.A.H.) and Agronomy (D.L.G.), The Pennsylvania State University, University Park, Pennsylvania 16802.
Plant Physiol. 1994 Mar;104(3):917-923. doi: 10.1104/pp.104.3.917.
High levels of cyclic [beta]-1,6-1,3-glucans (e.g. 0.1 mg mg-1 of total protein) are synthesized by free-living cells as well as by bacteroids of Bradyrhizobium japonicum USDA 110 (K.J. Miller, R.S. Gore, R. Johnson, A.J. Benesi, V.N. Reinhold [1990] J Bacteriol 172: 136-142; R.S. Gore and K.J. Miller [1993] Plant Physiol 102: 191-194). These molecules share structural features with glucan fragments isolated from the mycelial cell wall of the soybean (Glycine max) pathogen Phytophthora megasperma. These latter glucans have been shown to be potent elicitors (at nanogram levels) of the phytoalexin glyceollin in G. max. Using the well-characterized soybean cotyledon bioassay, we now show that the cyclic [beta]-1,6-1,3-glucans of B. japonicum USDA 110 are also biologically active elicitors of glyceollin production (but at microgram levels). We further show that both classes of [beta]-glucans elicit the production of the isoflavone daidzein within soybean cotyledon wound droplets.
高水平的环状β-1,6-1,3-葡聚糖(例如总蛋白含量为0.1毫克/毫克)可由自由生活的细胞以及日本慢生根瘤菌USDA 110的类菌体合成(K.J.米勒、R.S.戈尔、R.约翰逊、A.J.贝内西、V.N.莱因霍尔德[1990]《细菌学杂志》172: 136 - 142;R.S.戈尔和K.J.米勒[1993]《植物生理学》102: 191 - 194)。这些分子与从大豆(Glycine max)病原体大豆疫霉的菌丝细胞壁分离出的葡聚糖片段具有共同的结构特征。后一种葡聚糖已被证明是大豆中植保素大豆抗毒素(在纳克水平)的有效激发子。利用特征明确的大豆子叶生物测定法,我们现在表明日本慢生根瘤菌USDA 110的环状β-1,6-1,3-葡聚糖也是大豆抗毒素产生的生物活性激发子(但在微克水平)。我们进一步表明,这两类β-葡聚糖均可在大豆子叶伤口液滴中引发异黄酮大豆苷元的产生。