红麻细胞质雄性不育系与保持系花药活性氧代谢差异比较

Comparative research of reactive oxygen species metablisms of the CMS line and the maintainer lines in Kenaf(Hibiscus cannabinus)anther

关键词:  红麻  细胞质雄性不育  活性氧

Key words:  Kenaf  cytoplasmic male sterility  reactive oxygen species

摘要:

以红麻细胞质雄性不育系L23A及其保持系L23B为材料,比较其花药淀粉及可溶性糖含量变化并分析呼吸速率、活性氧产生速率、丙二醛(MDA)含量以及活性氧清除酶(POD、SOD)含量变化,来探讨活性氧伤害与红麻雄性不育的关系。结果表明:在小孢子发育的单核期,不育系呼吸速率与保持系差异不明显,但不育系花药O^-₂·含量高于保持系; 在双核期,不育系的呼吸速率明显低于其保持系,但不育系花药O^-₂·含量与保持系花药相近; 不育系在单核期和双核期的呼吸速率几乎没有变化,而保持系同一时期的呼吸速率呈明显增高趋势; 在不育系败育过程中,药隔维管组织中的大颗粒淀粉含量几乎不变,且不育系花药中的可溶性糖含量在单核期和双核期均低于保持系。推测是由于不育系花药中抗氰呼吸降低,一方面导致花药物质代谢和能量代谢的紊乱,不育系花药不能利用药隔组织中的淀粉粒,另一方面不能有效将细胞内过多电子通过抗氰呼吸传至O₂,引致不育花药中O^-₂·升高,从而导致MDA含量在单核期和双核期均高于保持系,同时POD的活性在单核期及双核期均低于保持系,而SOD活性在单核期高于保持系,在双核期则低于保持系。不育系花药在发育中,花药O^-₂·和MDA过量积累,以及SOD和POD酶活性降低,导致活性氧产生与清除失去平衡,花粉败育。

Abstract:

Kenaf(Hibiscus cannabinus)anther of the cytoplasmic male-sterile(CMS)line L23A and its maintainer line L23B were employeded as experimental materials to reveal the relationship between CMS and metabolisms of reactive oxygen species(ROS)by observing changes of starch and soluble sugar contents and comparing productions of superoxide anion radical(O^-₂·), respiratory rate as well as content of malonadehyde(MDA)and active oxygen exterminating enzymes(SOD and POD). The results showed that there was no evident difference between respiratory rate of CMS line and that of maintainer line at mononuclear stage, but anther of CMS line had higher content of O^-₂· than that of maintainer line at this stage. Respiratory rate in anther of the CMS was lower than that of maintainer line at binucleate pollen stage, while O^-₂· content in sterile anther approximated to that in fertile anther of maintainer line. There was no evident change in respiratory rate of CMS line at mononuclear stage and binucleate pollen stage, but respiratory rate in anther of maintainer line obviously increased from mononuclear stage to binucleate pollen stage. With the growth of anther, big starch grains content in L23A connective did not change during its microsporogenesis and soluble sugar content in L23A was lower than that of L23B at both of mononuclear stage and binucleate pollen stage. This possibility gave rise to the speculations that the decline of cyanide-resistant respiration in anther lead to disturbance of material metabolism and energy metabolism and starch grains presented in the connective tissue were not utilized by anther of the CMS line, meanwhile the intracellular surplus electrons were not effectively passed on to O₂ by cyanide-resistant respiration, which leads to increase O^-₂· content in anther of CMS line so that there is higher MDA content in anther of CMS line at mononuclear stage and binucleate pollen stage. Simultaneously, POD activity was lower than that of its maintainer line at mononuclear stage and binucleate pollen stage. While activitiy of SOD was higher than that of its maintainer line at mononuclear stage, but lower than that of its maintainer line at binucleate pollen stage. During the abortion of CMS anther, O^-₂·and MDA excessively accumulate in CMS anther and activity of SOD and POD would decline,which disrupted the balance between the production and elimination of ROS and made pollen mother cells apoptosis.