Kurkdjian A. C.
Institut des Sciences Vegetales, Centre National de la Recherche Scientifique, Bat. 22, Avenue de la Terrasse, F 91198 Gif-sur-Yvette Cedex, France.
Plant Physiol. 1995 Mar;107(3):783-790. doi: 10.1104/pp.107.3.783.
The stage of differentiation of epidermal cells and the development of root hairs was found to be important for the induction of depolarization in root hairs of Medicago sativa by Nod factor [NodRm-IV(S)] isolated from the bacterium Rhizobium meliloti. The electrical membrane response was concentration dependent, having its major effect (amplitude of the depolarization and number of root hairs that responded) at 10-8 and 10-7 M Nod factor. This response was correlated with a morphological effect of Nod factor in the root-hair-deformation bioassay at similar concentrations. The effect of Nod factor on depolarization and root-hair deformation showed specificity with respect to the structure, since unsulfated Nod molecules were inactive, as was the synthetic N,N',N",N"'- tetraacetylchitotetraose. The Nod factor that is O-acetylated at the nonreducing sugar was as efficient in root-hair deformation and membrane depolarization as the sulfated Nod factor.
研究发现,表皮细胞的分化阶段和根毛的发育对于从苜蓿根瘤菌中分离出的结瘤因子[NodRm-IV(S)]诱导紫花苜蓿根毛去极化至关重要。电膜反应具有浓度依赖性,在10^-8和10^-7 M的结瘤因子浓度下具有主要作用(去极化幅度和有反应的根毛数量)。这种反应与结瘤因子在类似浓度下的根毛变形生物测定中的形态学效应相关。结瘤因子对去极化和根毛变形的影响在结构方面表现出特异性,因为未硫酸化的结瘤分子无活性,合成的N,N',N",N"'-四乙酰壳四糖也是如此。在非还原糖处进行O-乙酰化的结瘤因子在根毛变形和膜去极化方面与硫酸化的结瘤因子一样有效。