盐度胁迫下盐生隐杆藻抗氧化防御系统的变化

盐生隐杆藻(Aphanothece halophytica)是在饱和NaCl条件下可以生存的少数几种耐盐蓝藻之一,作者研究了盐胁迫对盐生隐杆藻细胞内丙二醛含量、2种非酶抗氧化剂含量以及4种抗氧化酶活性的影响。与对照组相比,低盐胁迫和高盐胁迫都抑制盐生隐杆藻的生长。随着盐度胁迫程度的增加,丙二醛含量、非酶抗氧化剂含量和抗氧化酶(除了过氧化氢酶)活性不断增强。上述结果表明:盐胁迫下,盐生隐杆藻细胞内非酶抗氧化剂和抗氧化物酶水平的增加可以应对细胞内升高的氧化伤害,抗氧化防御系统可能在盐生隐杆藻对盐胁迫的耐受机制中发挥了重要作用。

Changes in antioxidative defense systems of Aphanothece halophytica in response to salt stresses

Aphanothece halophytica is a unique halotolerant cyanobacterium, which can grow even in saturated NaCl. In this study, we investigated the effect of salt stress on the levels of malondialdehyde, two non-enzymatic antioxidants and four antioxidant enzymes in A. halophytica. As compared to control salinity condition, an exposure to hyposaline or hypersaline conditions inhibited the growth of A. halophytica. With the increase of salt stresses, malondialdehyde content, levels of non-enzymatic antioxidants, and antioxidant enzymes increased continuously with the exception of catalase. These results suggest that the levels of non-enzymatic antioxidants and antioxidant enzymes in A. halophytica are increased to counteract the enhanced oxidative stress under salt stresses, and the antioxidant defense system may play an important role in the tolerance mechanism of salt stress.