过刊浏览

氮源对紫云英根瘤菌nod基因表达的作用

高丙利, 杨国平, 陈永萱, 沈思师, 游志鹏, 金润之

南京农业大学微生物系.江苏,南京 210095；中科院上海植物生理研究所.上海 200032

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#beta#-半乳糖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nodD2、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。

关键词： 氮源; 紫云英根瘤菌; nod基因; 抑制作用

Effect of nitrogen on the expression of nod genes in Rhizobium astragali (R. huakuii)

Gao Bingli, Yang Guoping, Chen Yongxuan, Shen Sishi, You Zhipeng, Jin Runzhi

Department of Microbiology,Nanjing Agricultural University.Nanjing 210095,Jiangsu；China

Abstract

Secretion of Nod factor which caused host 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. Nodulation of Rhizobium astragali could also be repressed by ammonium sulfate (2mmol/L) in Astragalus sinicus plants. By assaying for #beta#-galactosidase activity of nodA-lacZ, nodBC-lacZ, nodD1-lacZ and nodD2-lacZ fusion, we had found that high concentration of ammonium sulfate could repress the expression of nodD2, nodA and nodBC. The authors demonstrated that the expression of the common nodulation genes nodABC of R. astragali which determine early response functions to plant host signals and the regulatory gene nodD2 might be under the control of the level of combined nitrogen (NH~(+)_(4)).

Key words: Nitrogen;Rhizobium astragali;nod genes;Repressin

收稿日期：　　录用日期：

通讯作者：　　E-mail:

引用本文：

高丙利, 杨国平, 陈永萱, 沈思师, 游志鹏, 金润之. 氮源对紫云英根瘤菌nod基因表达的作用[J]. 生理学报 1997; 49 (4): .

Gao Bingli, Yang Guoping, Chen Yongxuan, Shen Sishi, You Zhipeng, Jin Runzhi. Effect of nitrogen on the expression of nod genes in Rhizobium astragali (R. huakuii). Acta Physiol Sin 1997; 49 (4): (in Chinese with English abstract).