Pretreatment with a Low Concentration of Methyl Viologen Decreases the Effects of Salt Stress on Chloroplast Ultrastructure in Rice Leaves (Oryza sativa L.)
Pretreatment with a Low Concentration of Methyl Viologen Decreases the Effects of Salt Stress on Chloroplast Ultrastructure in Rice Leaves (Oryza sativa L.)
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DOI：
10.1626/pps.7.435
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发表时间：
2004-01
影响因子：
2.5
通讯作者：
K. Yamane;Shahidur Rahman;M. Kawasaki;M. Taniguchi;H. Miyake
中科院分区：
文献类型：
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作者：
K. Yamane;Shahidur Rahman;M. Kawasaki;M. Taniguchi;H. Miyake
摘要研究了低浓度甲基紫精(MV)处理对盐胁迫诱导的水稻幼苗叶绿体退化的影响。在含有营养液的水培条件下生长3wk的幼苗，在水培条件下用100 nM MV处理3d，然后用不含MV的200 mMNaC l处理3d。在未经MV处理的植株中，在盐处理过程中，叶绿素含量急剧下降，伴随着类囊体膨胀和类囊体膜的破坏。MV预处理可减轻上述损伤。盐胁迫下，两种植物叶绿体中的铜锌超氧化物歧化酶和铁超氧化物歧化酶活性在盐胁迫下均增强。在未经MV处理的盐胁迫下，抗坏血酸过氧化物酶(APX)活性与对照差异不显著。然而，在MV处理的植株中，盐胁迫下的APX活性大约是对照的1.2-1.3倍。盐处理植株的过氧化氢酶(CAT)活性下降到对照的52%，MV处理抑制了CAT活性的下降。这些结果表明，MV通过提高APX活性和阻止CAT活性的下降来减轻盐胁迫对叶绿体的伤害。
Abstract We investigated the effects of pretreatment with a low concentration of methyl viologen (MV) on the salinity-induced chloroplast degeneration in rice seedlings. The seedlings grown in hydroponic culture containing nutrient solution for 3 wks were treated with 100 nM MV mixed in the hydroponic culture for 3 days, and then with 200 mM NaCl without MV for 3 days. In the plants without MV pretreatment, the chlorophyll content drastically decreased during the NaCl treatment accompanied by swelling of thylakoids and destruction of thylakoid membranes. These damages were alleviated by the pretreatment with MV. The activities of CuZn-SOD and Fe-SOD, which localize in chloroplasts, increased under salt stress in both plants with and without MV pretreatment. In the plants under salt stress without MV pretreatment, ascorbate peroxidase (APX) activity did not differ from that of control. However, in MV-pretreated plants, APX activity under salt stress was about 1.2- to 1.3-fold higher than that of the control. Catalase (CAT) activity in NaCl treated plants was decreased to 52% of the control and the reduction in CAT activity was suppressed by MV pretreatment. These results suggest that MV reduced the damages by salt stress in chloroplasts by increasing APX activity and preventing the decrease in CAT activity.