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以大豆‘中黄13’为材料,研究人工老化后大豆种子活力及线粒体抗坏血酸-谷胱甘肽(ASC-GSH)循环的变化。结果表明,随老化时间的延长,大豆种子的发芽率、发芽势、发芽指数和活力指数均显著下降;老化种子的相对电导率和丙二醛(MDA)含量随着老化时间的延长逐渐增大,超氧阴离子(O_2?~-)产生速率和过氧化氢(H_2O_2)含量呈现先升高后降低的趋势;与对照相比,老化种子中线粒体细胞色素c氧化酶(COX)和苹果酸脱氢酶(MDH)活性显著下降,呼吸速率和呼吸控制率(RCR)显著降低;老化种子中线粒体超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、单脱氢抗坏血酸还原酶(MDHAR)、脱氢抗坏血酸还原酶(DHAR)和谷胱甘肽还原酶(GR)的活性以及总ASC和GSH含量显著降低,说明老化导致活性氧(ROS)代谢异常,线粒体呼吸功能及ASC-GSH循环紊乱。ROS的过量积累可能是导致种子活力丧失的主要原因。
Soybean ’Zhonghuang 13’ was used to study the changes of soybean seed vitality and mitochondrial ascorbate-glutathione (ASC-GSH) circulation after artificial aging. The results showed that the germination rate, germination energy, germination index and vigor index decreased significantly with the aging time. The relative electrical conductivity and malondialdehyde (MDA) content of the aged seeds gradually increased with the aging time , The generation rate of O_2 ~ ~ - and the content of hydrogen peroxide (H_2O_2) increased at first and then decreased. Compared with the control, the contents of mitochondrial cytochrome c oxidase (COX) and malic acid While the respiratory rate and respiratory control rate (RCR) decreased significantly. The content of mitochondrial superoxide dismutase (SOD), ascorbate peroxidase (APX), monodehydroascorbate reductase MDHAR, DHAR and GR as well as the content of total ASC and GSH were significantly decreased, indicating that the aging resulted in abnormal ROS metabolism, mitochondrial respiratory function and ASC-GSH Circulatory disorders. Over-accumulation of ROS may be the main reason for the loss of seed vigor.