摘要
高浓度的硫酸铵阻碍了紫云英根瘤菌诱导紫云英根毛发生典型的根毛变形并明显抑制了紫云英结瘤能力。通过对融合子的β-半乳精苷酶活性的测定进一步表明高浓度的硫酸铵对紫云英的结瘤调节基因nodDZ、共同结瘤基因nodA及nodBC的表达有抑制作用而对结瘤调节基因nodD1的表达无抑制作用。
Secretion of Nod factor which caused hst root hair deformation (Had phenotype) could be inhibited by ammonium sulfate at high concentration in Rhizobium astragali (R. huakuii). Other combined forms of nitrogen such as potassium nitrate, urea and Asp had a small effect on the expression of nod genes (Figs. 1, 2).Nodulation of Rhizobium astragali could also be repressed by ammonium sulfate (2 mml/L) in Astragalus sinicus plants (Figs. 3, 4 ).By assaying for β-galactosidase activity of nodA-lacZ, nodBC-lacZ,nodD 1-lacZ and nodD2-lacZ fusion, we had fund that high concentration of ammonium sulfate could repress the expressin of nodD2, nodA and nodBC (Fig. 5 ). We demnstrated that the expressin of the cmmn ndulation genes ndABC of R. astragali which determine early respnse functions to plant host signals and the regulatory gene nodD2 might be under the control of the level of combined nitrogen (NH4).
基金
植物分子遗传国家重点实验室资助
