Changes in activities of antioxidant enzymes and lipoxygenase during growth of sunflower seedlings from seeds of different vigour
Changes in activities of antioxidant enzymes and lipoxygenase during growth of sunflower seedlings from seeds of different vigour
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DOI：
10.1079/ssr200197
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发表时间：
2002-03-01
影响因子：
2.1
通讯作者：
Corbineau, F
中科院分区：
文献类型：
--
作者：
Bailly, C;Bogatek-Leszczynska, R;Corbineau, F
本研究旨在探讨向日葵幼苗在15℃黑暗条件下的生长与清除活性氧自由基(ROS)，特别是超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽还原酶(GR)的活性，以及与产生自由基，即脂氧合酶(LOX)的关系。将未经处理的对照种子与加速老化(45℃，相对湿度100%，5d)、渗透(15℃，聚乙二醇液-2 Mpa，渗透7d)和加速老化后引发的种子进行比较。加速老化降低了种子的发芽力，减缓了下胚轴的生长，而引发则提高了种子的发芽率，促进了幼苗的发育。老化种子的渗透处理几乎完全恢复了萌发和幼苗生长的初始速率。除超氧化物歧化酶外，其余酶活性在种子萌发和幼苗发育过程中均呈上升趋势。种子吸胀或胚根突起主要与CAT活性增加有关，其次与GR活性增加有关。LOX活性的增加与下胚轴伸长的开始明显相关。然而，在所有病例中，丙二醛测量并未显示强烈的脂质过氧化。与对照相比，在种子吸胀过程中或幼苗发育的非常早期，引发对CAT和GR的刺激作用显著，尤其是对老化种子产生的幼苗。种子和幼苗的过氧化氢(H2 0 2)含量与CAT和GR活性及幼苗发育动力学密切相关。研究结果表明，向日葵种子活力与ROS清除能力之间存在明显的相关性。
The aim of this study was to investigate whether there was a relationship between growth of sunflower seedlings at 15degreesC in the dark and activities of enzymes involved in scavenging of reactive oxygen species (ROS), especially superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR), or in production of free radicals, namely lipoxygenase (LOX). Untreated control seeds were compared with seeds exposed to accelerated ageing (5 d at 45degreesC and 100% relative humidity), osmopriming (7 d at 15degreesC with a polyethylene glycol (PEG) solution at -2 MPa) and accelerated ageing followed by priming. Accelerated ageing decreased seed germinability and slowed down hypocotyl growth, whereas priming resulted in an increase in germination rate and enhanced seedling development. Osmopriming of aged seeds almost completely restored the initial rate of germination and seedling growth. The activity of all the enzymes studied increased during seed germination and seedling development, except that of SOD. Seed imbibition or radicle protrusion were related mainly with an increase in CAT activity and, to a lesser extent, in GR activity. Increase of LOX activity was clearly associated with the onset of hypocotyl elongation. However, in all cases, malondialdehyde measurements did not reveal intense lipid peroxidation. Priming induced a marked stimulation of CAT and GR during seed imbibition or very early during seedling development, as compared to the control seedlings and particularly to the seedlings generated by aged seeds. Hydrogen peroxide (H 202) contents of seeds and seedlings were closely correlated to the activities of CAT and GR and to the kinetics of seedling development. The results obtained establish a clear relationship between sunflower seed vigour and ROS scavenging.