Induction of antioxygenic enzymes as defense systems in plant cells against low temperature stress : (II) $Mn^{+2}-induced$ SOD activation and enhancement of cold tolerance in rice seedlings

식물의 냉해에 대한 생체방어기구로서 항산소성 효소의 유도 : (II) $Mn^{+2}$이온에 의한 세포내 SOD의 활성화와 벼 유묘의 내냉성 향상

  • Hahn, Chang-Kyun (Department of Agricultural Chemistry, Seoul National University) ;
  • Kim, Jong-Pyung (Department of Agricultural Chemistry, Seoul National University) ;
  • Jung, Jin (Department of Agricultural Chemistry, Seoul National University)
  • 한창균 (서울대학교 농과대학 농화학과) ;
  • 김종평 (서울대학교 농과대학 농화학과) ;
  • 정진 (서울대학교 농과대학 농화학과)
  • Published : 1991.06.30

Abstract

The uptake of $Mn^{+2}$, a metal cofactor Mn-SOD, by rice seedings resulted in not only a substantial increase in SOD activity in leaf tissues of the plants, but also a significant enhancement of their cold tolerance : the relative extent of the cold tolerance appeared to accord with relative level of the SOD activity. In contrast, $Fe^{+3},\;Cu^{+2}$ and $Zn^{+2}$, which are the cofactors of Fe-SOD and Cu/Zn-SOD, were found to be ineffective for increasing the SOD activity as well as for improving the chilling-resistant capacity of the plants. The results suggest that Mn-SOD, which is most likely induced by its substrate(superoxide) and activated by the presence of $Mn^{+2}$a at high level, is the enzyme acting as an active component of the defense system against low temperature stress in rice plants. In addition, the application of abscisic acid which has been know to protect to some extent certain plants from chilling injury brought about an increase in SOD activity in rice tissues, providing another affirmative information for the crucial role of SOD under the circumstance of cold stress in plants.