几种水稻联合固氮菌吸氢酶(hup)基因的鉴定及分析

IDENTIFICATION AND ANALYSIS OF HYDROGEN UPTAKE (HUP) GENES OF SEVERAL ASSOCIATIVE NITROGEN FIXING BACTERIA WITH RICE PLANT

供试菌株Alcaligenes faecalis A15,Enterobacter cloacae EnSs.E·cl-oacae E26,Klebsiella planticola DWUL2.K·oxytoca NG13和Pseudomonassacharophila均能还原2,3,5-氯化三苯基四氮唑(TTC),说明它们含有吸氢酶。以Rhizobium japonicum的hup基因为探针进行杂交的结果表明。除E·oloacae E26和K·oxytoca NG13外,其它菌株的DNA与hup探针具有同源性。A·faecalis A15 hup基因位于染色体上‘E·cloacae EnSs则位于较大的一个质粒上。A·faecalis A15和E·Cloacae EnSs的nif基因与hup基因位于同一复制子上。hup基因不具必然的保守性,因此异源hup基因探针不一定都适宜于探测hup基因。

All of the tested species ( strains ) in this work can reduce TTC, suggesting that they contain hydrogen uptake hydrogenase. Hybridization with Rhizobium japonicum hup gene indicated that there was homology between restricted DNA and the probe for Alcaligenes faecalis Al5, Enterobac-ter cloacae EnSs, Klebsiella planticola DWUL2 and Pseudomonas saccharo-phila.Negative results were obtained for E. cloacae E26 and K. oxytoca NG13.Hup genes of A.faecalis Al5 were located on chromosomal DNA,however, it was located on the larger plasmid for E .cloacae EnSs.Nif gene and hup gene arc located on the same replicon. Hup gene from different hup+ microorganisms was not homology inevitably.