Juvenility of tobacco induced by cytokinin gene introduction decreases susceptibility to Tobacco necrosis virus and confers tolerance to oxidative stress
Juvenility of tobacco induced by cytokinin gene introduction decreases susceptibility to Tobacco necrosis virus and confers tolerance to oxidative stress
复制标题
DOI：
10.1016/j.pmpp.2004.10.006
复制
发表时间：
2004-07-01
影响因子：
2.7
通讯作者：
Barna, B
中科院分区：
文献类型：
--
作者：
Pogány, M;Koehl, J;Barna, B
研究了转CaMV 35S：ipt基因烟草系(CTKm)对烟草坏死病毒(TNV)的敏感性。逆转录-聚合酶链式反应证实了ipt基因的表达。由于转基因引起的细胞分裂素过量，CTKm植株的衰老被大大延缓。与对照相比，转基因烟草的病毒诱导的坏死灶数量和外壳蛋白含量均显著降低。CTKm烟草叶盘接种TNV后产生的乙烯和乙烷较少，表明其抗逆性较强，膜脂过氧化水平较低。与SR1对照相比，未接种和侵染TNV的CTKm烟草叶片中的H_2O_2积累均受到抑制。抗坏血酸过氧化物酶、谷胱甘肽S转移酶、过氧化氢酶三种抗氧化酶活性和非酶类抗氧化剂抗坏血酸的含量均显著高于对照烟叶，说明烟叶对除草剂百草枯诱导的氧化胁迫表现出较强的耐受性。因此，通过导入细胞分裂素基因来抑制衰老，可以更有效地清除活性氧(ROS)，从而减轻脂质过氧化，并可能有助于抵抗TNV诱导的坏死发展。(C)2004爱思唯尔有限公司。保留所有权利。
Tobacco necrosis virus (TNV) susceptibility of a cytokinin overproducing tobacco line (CTKm) transformed with a CaMV 35S:ipt gene construct was studied. Expression of the ipt gene was confirmed by RT-PCR. As a result of cytokinin excess caused by the transgene, senescence of CTKm plants was greatly delayed. The number of virus-induced necrotic lesions as well as the coat protein content were significantly lower in the transgenic tobacco, as compared with the control. Leaf discs of CTKm tobacco produced less ethylene and ethane upon inoculation with TNV, which indicated higher stress tolerance and lower level of lipid peroxidation. Diminished H2O2 accumulation was observed in both uninoculated and TNV-infected CTKm tobacco leaves as compared to the SR1 control line. The activity of three antioxidant enzymes (ascorbate peroxidase, glutathione S-transferase, catalase) and the amount of the non-enzymatic antioxidant ascorbic acid were markedly higher in healthy CTKm tobacco leaves and accordingly, CTKm tobacco leaves exhibited tolerance to oxidative stress induced by the herbicide paraquat as compared to control tobacco leaves. Therefore, inhibition of senescence resulting from cytokinin gene introduction confers more efficient reactive oxygen species (ROS) scavenging ability, which may attenuate lipid peroxidation and presumably contributes to the resistance against TNV-induced necrosis development. (c) 2004 Elsevier Ltd. All rights reserved.