Metabolism of reactive oxygen species in the cytoplasmic male-sterile cotton anther

chinois. 阐述棉花细胞质雄性不育花药的活性氧产生与清除的代谢规律。以棉花细胞质雄性不育系、保持系和杂种F1的不同发育时期花药为材料，分析3个活性氧指标（超氧阴离子、过氧化氢和丙二醛）和活性氧清除酶（超氧化物歧化酶、过氧化氢酶和过氧化物酶）的含量变化，比较3种材料的活性氧产生与清除的代谢状况差异。比较分析发现，在不育系败育初期的花药中，超氧阴离子（O2and#8226;C）、过氧化氢（H2O2）和丙二醛（MDA）3个对细胞有毒性的活性氧指标均高于保持系或杂种F1的花药，同时对活性氧具有清除作用的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）3个抗氧化酶活性也随着提高，表明败育初期花药的活性氧增加对抗氧化酶有诱导作用。但在败育盛期的不育花药中，一方面O2and#8226;C、H2O2和MDA含量极显著高，另一方面SOD、CAT、POD酶活性却极显著低，导致活性氧产生与清除失去平衡，这时花粉母细胞大量凋亡。在败育后的花药中，O2and#8226;C和H2O2含量与可育花药相近，但MDA含量仍持续提高，以及SOD、CAT、POD酶活性持续降低，表明雄性细胞凋亡后活性氧对花药仍有不利影响。花药O2and#8226;C、H2O2和MDA的过量积累，以及其清除酶活性的显著降低，这一过程在棉花不育花药中是与雄性细胞凋亡同步发生的，但在恢复基因引入后的杂种F1花药中，过量产生的活性氧可被清除。

anglais. The study was conducted in order to elucidate the metabolic mechanism of reactive oxygen species (ROS) production and scavenging in the CMS cotton anthers. Cotton anthers of the cytoplasmic male-sterile (CMS) line, maintainer and hybrid F1 at different developmental stages, were employed for studying the relationship between CMS and metabolism of reactive oxygen species (ROS) by comparing the metabolism changes in the production and scavenging of ROS. The results showed that during the abortion preliminary stage (sporogenous cell division stage), anthers of CMS line had higher contents of O2and#8226;C, H2O2 and MDA than those of maintainer or hybrid F1. Simultaneously, the higher activities of SOD, CAT and POD were measured in anthers of CMS line, indicating that an increase of ROS in anthers of abortion preliminary stage had inducible effects on the antioxidant enzymes. But during the abortion peak of CMS anther (pollen mother cell meiosis stage), contents of O2and#8226;C, H2O2 and MDA were extraordinarily high in CMS anthers. The activities of SOD, CAT and POD were excessively low, which disrupted the balance between the production and elimination of ROS and made pollen mother cells apoptosis at this stage. At the following two stages (uninucleate microspore stage and mature pollen stage), contents of O2and#8226;C and H2O2 in aborted anthers approximated to contents in fertile anthers of maintainer and hybrid F1. However, MDA contents were continuously rising and enzymic activities of SOD, CAT and POD were decreased in sterile anthers, which indicated that ROS had harmful effects on the anthers after the apoptosis of male cells. Excessive accumulation of O2and#8226;C, H2O2 and MDA and significant reduction of ROS scavenging-enzyme activities were coinstantaneous with male cells apoptosis in the anthers of cotton CMS line. But when the restorer gene was transferred into CMS line, excessive production of ROS could be eliminated in the anthers of hybrid F1.