Rhizobium meliloti 102F51 Mutants Defective in Heme Synthesis

Heme 합성특성이 다른 Rhizobium meliloti 102F51 Mutant의 선별

  • 최영주 (경상대학교 농과대학 농화학과) ;
  • 정원화 (경상대학교 농과대학 농화학과) ;
  • 김경수 (경상대학교 농과대학 농화학과) ;
  • 신평균 (경상대학교 농과대학 농화학과) ;
  • 조무제 (경상대학교 농과대학 농화학과)
  • Published : 1986.06.01

Abstract

Rhizobium meliloti 102 F 51, the symbiotic partner of alfalfa, was mutagenized with N-methyl-N'-nitro-N-nitrosoguanidine (NTG) and UV-irradiation. Three group of mutants which form white, white-pink and red nodules were selected. The adetylene reduction activity, nodulation activity, amount of heme synthesis during the nodulation, and ${\delta}-aminolevulinic$ acid synthetase (ALAS) and ${\delta}-aminolevulinic$ acid dehydratase (ALAD) activities in free living rhizobia and bacteroid states of the each group of mutants were compared. The mutants forming white nodules showed lower acetylene reduction activity compared to those of red nodule forming mutants. The two key enzymes for the heme synthetic pathway, ALAS and ALAD activities of the mutants forming red nodules was much higher than those of the mutants forming white nodules in bacteroid state, however no significant difference was observed in free living state. In the nodules the ALAS was detected only in bacteroid fraction, while ALAD was detected both in bacteroid and plant fraction. ALAS was dramatically increased with the heme synthesis during the nodulation, while ALAD was decreased in plant fraction but slight increase was observed in bacteroid fraction.

Keywords

Rhizobium meliloti;heme synthesis