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211.
Catello Pane Loredana Sigillo Michele Caputo Giovanna Serratore Massimo Zaccardelli 《Archives Of Phytopathology And Plant Protection》2017,50(3-4):167-177
In the present study, 26 accessions of rocket salad belonging to four species (Eruca sativa Mill., Diplotaxis tenuifolia (L.) DC., Diplotaxis muralis (L.) DC. and Erucastrum spp.) were tested for resistance to damping-off, wilting and leaf spot disease causal agents. High susceptibility to Rhizoctonia solani was detected in all accessions while variability in rocket seedling susceptibility for Sclerotinia assays was observed. Susceptibility to wilting caused by the fungus Fusarium oxysporum f. sp. raphani was tested. E. sativa varieties exhibited a lower severity degree associated to yellowing-related symptoms compared to D. tenuifolia. Resistance assay using the bacterium Xanthomonas campestris pv. campestris was also performed. Five E. sativa varieties showed a disease incidence lower than 60% while all the D. tenuifolia accessions, showed a susceptibility of 100%. The present study represents a step towards the identification of genetic resources useful in breeding for the selections of novel resistant varieties. 相似文献
212.
主要从DNA一级结构及抗氧化酶系变化两方面,研究了Hg2+胁迫下浮萍体细胞的损伤。结果表明:运用随机扩增多态性DNA法(Random amplified polymorphism DNA, RAPD)和DNA梯法(DNA Ladder),5~10 mg·L-1 Hg2+处理组可检测到基因组DNA的明显损伤,20 mg·-1 Hg2+已导致细胞坏死;RAPD法较DNA Ladder法更灵敏。本文还发现,活性氧和抗氧化酶系很可能参与了浮萍体细胞凋亡过程。低浓度的Hg2+胁迫可刺激抗氧化酶活性升高,以清除体内活性氧,而一旦活性氧水平超出一定域值,抗氧化酶活性急速下降,导致细胞凋亡。 相似文献
213.
Bibhas Guha Anisur Rahman Khuda-Bukhsh 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》2003,542(1-2):1-13
Genotoxic effects have been assessed in the fish Oreochromis mossambicus treated separately and conjointly with 0.2% ethylmethane sulphonate (EMS) and 0.05% β-carotene (BC) during five different time periods (6, 24, 48, 72 and 96 h) by analysis of endpoints such as chromosome aberrations, abnormal red blood cell nuclei, abnormal sperm morphology and protein contents (both qualitative and quantitative) of selected tissues, viz. muscle, heart, eye, brain, gill, liver, spleen and kidney. In addition, the relative efficacy of three doses of BC 0.02, 0.05 and 0.1%, in ameliorating genotoxic effects of 0.2% EMS was also tested after a treatment period of 48 h. EMS caused chromosomal aberrations, nuclear anomalies in red blood cells, abnormal sperm morphology and an apparent alteration of protein synthesis in various tissues. Some of these genotoxic effects of EMS appeared to be ameliorated by all three doses of BC, of which the 0.02% dose showed a marginally better efficacy. 相似文献
214.
Fujita S Ito T Mizutani T Minoguchi S Yamamichi N Sakurai K Iba H 《Journal of molecular biology》2008,379(3):492-504
Methylation of cytosine residues in CpG dinucleotides plays an important role in epigenetic regulation of gene expression and chromatin structure/stability in higher eukaryotes. DNA methylation patterns are established and maintained at CpG dinucleotides by DNA methyltransferases (Dnmt1, Dnmt3a, and Dnmt3b). In mammals and many other eukaryotes, the CpG dinucleotide is underrepresented in the genome. This loss is postulated to be the result of unrepaired deamination of cytosine and 5-methylcytosine to uracil and thymine, respectively. Two thymine glycosylases are believed to reduce the impact of 5-methylcytosine deamination. G/T mismatch-specific thymine-DNA glycosylase (Tdg) and methyl-CpG binding domain protein 4 can both excise uracil or thymine at U·G and T·G mismatches to initiate base excision repair. Here, we report the characterization of interactions between Dnmt3b and both Tdg and methyl-CpG binding domain protein 4. Our results demonstrate (1) that both Tdg and Dnmt3b are colocalized to heterochromatin and (2) reduction of T·G mismatch repair efficiency upon loss of DNA methyltransferase expression, as well as a requirement for an RNA component for correct T·G mismatch repair. 相似文献
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萱草属有毒植物的研究 总被引:1,自引:0,他引:1
萱草属中某些种的根含神经性毒物,家畜采食或饲喂实验动物能引起中毒病的发生。在鉴于此对北萱草,黄花菜,北黄花菜,小黄花菜进行了植物调查鉴定及有毒成分—萱草根素的提取分离与毒性和结构再鉴定的研究,确认除黄花菜根外其它3种均含有萱草根素。讨论了黄花菜种鉴定中存在的问题。 相似文献
220.
Ana López-Ballesteros Emilio Rodríguez-Caballero Gerardo Moreno Paula Escribano Ana-Maria Hereş Jorge Curiel Yuste 《Global Change Biology》2023,29(22):6336-6349
Forest decline events have increased worldwide over the last decades being holm oak (Quercus ilex L.) one of the tree species with the most worrying trends across Europe. Since this is one of the tree species with the southernmost distribution within the European continent, its vulnerability to climate change is a phenomenon of enormous ecological importance. Previous research identified drought and soil pathogens as the main causes behind holm oak decline. However, despite tree health loss is a multifactorial phenomenon where abiotic and biotic factors interact in time and space, there are some abiotic factors whose influence has been commonly overlooked. Here, we evaluate how land use (forests versus savannas), topography, and climate extremes jointly determine the spatiotemporal patterns of holm oak defoliation trends over almost three decades (1987–2014) in Spain, where holm oak represents the 25% of the national forested area. We found an increasing defoliation trend in 119 out of the total 134 holm oak plots evaluated, being this defoliation trend significantly higher in forests compared with savannas. Moreover, we have detected that the interaction between topography (which covariates with the land use) and summer precipitation anomalies explains trends of holm oak decline across the Mediterranean region. While a higher occurrence of dry summers increases defoliation trends in steeper terrains where forests dominate, an inverse relationship was found in flatter terrains where savannas are mainly located. These opposite relationships suggest different causal mechanisms behind decline. Whereas hydric stress is likely to occur in steeper terrains where soil water holding capacity is limited, soil waterlogging usually occurs in flatter terrains what increases tree vulnerability to soil pathogens. Our results contribute to the growing evidence of the influence of local topography on forest resilience and could assist in the identification of potential tree decline hotspots and its main causes over the Mediterranean region. 相似文献