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101.
Helge Sierotzki Sandro Parisi Ute Steinfeld Isabel Tenzer Sylvie Poirey Ulrich Gisi 《Pest management science》2000,56(10):833-841
Field isolates of Mycosphaerella fijiensis, causing black Sigatoka of banana, were characterised for their sensitivity to different inhibitors of the cytochrome bc1 enzyme complex (Qo respiration inhibitors, strobilurin fungicides), using physiological, biochemical and molecular genetic methods. Strobilurin‐resistant isolates exhibited very high resistance factors both in mycelial growth inhibition and NADH consumption assays. Cross‐resistance was observed among all Qo inhibitors, including trifloxystrobin, azoxystrobin, famoxadone, strobilurin B and myxothiazol. However, the Qi and the cytochrome aa3 inhibitors, antimycin A and potassium cyanide, respectively, were not cross‐resistant to Qo inhibitors. In sensitive but not in resistant isolates, mixtures of Qo inhibitors and SHAM, an inhibitor of the alternative oxidase (AOX), were more active than the components alone, indicating that the alternative pathway is essential in metabolism, but not causal for resistance. In the cell‐free NADH‐consumption assay, the Qo inhibitors affected the sensitive but not the resistant isolates, suggesting that AOX was not active in sub‐mitochondrial particles. In whole cells, however, the AOX has a basic expression level and is probably not inducible by trifloxystrobin. Sequencing of the cytochrome b gene of sensitive and resistant M fijiensis isolates revealed a difference in the nucleotide sequence leading to a single amino acid change from glycine to alanine at position 143 in the resistant isolate. This change is known to occur also in the naturally tolerant basidiomycete Mycena galopoda. It is suggested that the field isolates of M fijiensis can acquire resistance to Qo inhibitors due to a target site alteration with a single base pair change. Resistant isolates do not seem to contain a mixture of mutated and non‐mutated DNA, indicating a complete selection of resistant mitochondria and a maternally donated mode of resistance. © 2000 Society of Chemical Industry 相似文献
102.
甘蔗基因表达定量PCR分析中内参基因的选择 总被引:8,自引:0,他引:8
以甘蔗接种黑穗病菌后0、6、12、24、48、60和72 h时间点的材料为研究对象,应用实时荧光定量PCR(real-time quantitative PCR Real-time qPCR)技术,探讨25S rRNA、GAPDH、β-actin和β-tubulin4个内参基因mRNA水平的表达情况.经geNorm程序统计学分析,4种内参基因的表达稳定性各异,25S rRNA>GAPDH>β-actin>-tubulin,其中以25S rRNA表达稳定性最好,且根据该基因设计的两对定量PCR引物都是可行的.同时,甘蔗PPO基因表达特性的定量PCR分析也显示,甘蔗PPO基因与植物的抗病性相关.结果显示,研究中所筛选的内参基因是合适的. 相似文献
103.
104.
105.
反义ACC氧化酶基因的导入对番茄乙烯生成的抑制作用 总被引:14,自引:0,他引:14
将反向克隆的ACC氧化酶基因通过Ti质粒导入到番茄基因组中,转基因番茄植株叶片和果实中ACC氧化酶活性和乙烯产生速率均受到显著抑制,显示出反义基因能抑制靶基因(ACC氧化酶)的表达。子代抗性标记基因的分离结果表明呈单基因遗传。 相似文献
106.
葡萄多酚含量和多酚氧化酶(PPO)活性与组培苗生根关系的初步研究 总被引:2,自引:0,他引:2
研究测定了葡萄属10个种(品种)组培苗的多酚含量和多酚氧化酶(PolyphenolOxidase,PPO)的活性,对其与组培苗的生根指数进行相关性分析,并建立生根指数与多酚含量、多酚氧化酶的多项式回归方程。结果表明:不同种(品种)间多酚含量和PPO活性有显著性差异;多酚含量和PPO活性相关性显著,PPO活性和生根指数不相关,而多酚含量与生根指数呈显著负相关;从回归方程可以看出,PPO活性对生根指数的作用是非线性的,多酚含量对生根指数的作用是线性的,这说明多酚含量对组培苗生根的直接作用很大,PPO活性通过多酚含量间接影响组培苗生根而且直接作用较小。 相似文献
107.
小麦细胞质雄性不育系、保持系花药三个不同发育时期的邻苯二酚氧化酶同工酶存在明显差异,不育系中的同工酶谱带数多于保持系.考虑到小麦细胞质雄性不育系的细胞核与保持系相同,但具有与保持系不相同的不育细胞质,故邻苯二酚氧化酶同工酶可能与植物的雄性不育特性有某种联系.雌蕊中的邻苯二酚氧化酶同工酶在不育系与保持系间基本相同,这可能与雌蕊中不育系、保持系间的核质组成相同有关,这一事实似乎从另一侧面说明了邻苯二酚氧化酶与不育特性存在着某种联系. 相似文献
108.
R. J. Bino L. C. J. M. Suurs S. J. de Hoop A. Van Der Neut J. L. Van Went G. A. M. Van Marrewijk 《Euphytica》1986,35(3):905-918
Summary Anthers of male fertile, cytoplasmic male sterile (cms), and restored male fertile Petunia hybrida, are analyzed for cytochrome c oxidase (cox) activity in subsequent stages of microsporogenesis, and compared with anthers of male fertile, cms-S and cms-C Zea mays. The cox activity is determined in anther extracts and cytochemically. In petunia anthers, the first differences in cox activity occur from meiosis onward. However, at these stages, the initial symptoms of degeneration are already apparent. It is suggested that the decline in enzyme activity of the cms petunia anthers is the result rather than the cause of the non-formation of functional pollen.In maize anthers, the cox activity of sterile-type anthers is reduced in comparison with fertile-type anthers from premeiosis onward. There are also consistent cytochemical differences in the mitochondrial organization of cox activity between pollen of cms-S and male ferile maize anthers. In fertile-type mitochondria, the DAB reaction product indicating cox activity is localized in the cristae and within the space between the outer and inner limiting membranes of the organelles. In mitochondria of pollen of cms-S maize, cox activity is only observed between the outer and inner membranes of the mitochondria. The biochemical and cytochemical differences are observed at stages of development at which no structural signs of degeneration are apparent. The results suggest that cms in maize correlates with deviations in cytochrome c oxidase activity.Abbreviations cox
cytochrome c oxidase
- DAB
3,3-diaminobenzidine 相似文献
109.
The effect of polyethylene glycol–induced osmotic stress on the activity of nitrate reductase, glutamine synthetase, and glycolate oxidase in leaves of young barley plants grown under two nutrient‐supply regimes was studied. The activity of nitrate reductase gradually decreased after polyethylene glycol (PEG) application, while glutamine synthetase and glycolate oxidase were increased. It is speculated that the enhanced glutamine synthetase and glycolate oxidase activities are due to increased flux of metabolites through the photorespiratory cycle. Prominent increase in concentrations of free proline, reducing sugars, and free amino acids was observed. The possible contribution of these cellular solutes to the process of osmotic adjustment and the role of mineral supply is discussed. It is suggested that low N supply in combination with stress conditions switched the preferred osmolyte type from amino acids (N‐containing) to sugars (C‐containing). 相似文献
110.