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排序方式: 共有1008条查询结果,搜索用时 31 毫秒
51.
52.
《Fungal Ecology》2016
Fungi play a key role in decomposition of submerged wood in streams, breaking down lignocelluloses and releasing nutrients, and are important in ecosystem functioning. These wood decay fungi are known as freshwater lignicolous fungi and are usually studied by collecting submerged woody litter, followed by incubation in a moist chamber. This review explains what are freshwater lignicolous fungi, their decay mechanisms, roles and physiological attributes. Asian/Australasian lignicolous freshwater fungi have been relatively well-surveyed and enable an account of their distribution along a latitudinal transect. Unlike freshwater leaf-dwelling fungi their diversity in water bodies is greater towards the Equator which suggests they are important for decaying submerged wood in the tropics. Riparian vegetation, disturbances such as pollution, streams drying and study methods, may all affect the diversity of freshwater lignicolous fungi, however, the overall trend is a higher diversity in the tropics and subtropics. Climate changes together with increasing deposition of woody debris from human activities, and alteration of environmental factors (such as water pollution, and dam building) will impact freshwater lignicolous fungi. Changing diversity, structure and activities of freshwater fungal communities can be expected, which will significantly impact on aquatic ecosystems, particularly on nutrient and carbon cycles. There is a great opportunity to monitor changes in freshwater fungi communities along latitudinal (north to south) and habitat gradients (from human disturbed to natural habitats), and study ecological thresholds and consequences of such changes, particularly its feedback on nutrient and carbon cycles in freshwater systems. 相似文献
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54.
Global patterns in fine root decomposition: climate,chemistry, mycorrhizal association and woodiness
Craig R. See Michael Luke McCormack Sarah E. Hobbie Habacuc Flores‐Moreno Whendee L. Silver Peter G. Kennedy 《Ecology letters》2019,22(6):946-953
Fine root decomposition constitutes a critical yet poorly understood flux of carbon and nutrients in terrestrial ecosystems. Here, we present the first large‐scale synthesis of species trait effects on the early stages of fine root decomposition at both global and local scales. Based on decomposition rates for 279 plant species across 105 studies and 176 sites, we found that mycorrhizal association and woodiness are the best categorical traits for predicting rates of fine root decomposition. Consistent positive effects of nitrogen and phosphorus concentrations and negative effects of lignin concentration emerged on decomposition rates within sites. Similar relationships were present across sites, along with positive effects of temperature and moisture. Calcium was not consistently related to decomposition rate at either scale. While the chemical drivers of fine root decomposition parallel those of leaf decomposition, our results indicate that the best plant functional groups for predicting fine root decomposition differ from those predicting leaf decomposition. 相似文献
55.
无义介导的mRNA降解途径(nonsense-mediated mRNA decay,NMD)作为细胞内的一种重要的mRNA质量监控机制,可以降解含有提前终止密码子(premature termination codon,PTC)的异常转录本,从而避免截短蛋白质对细胞的毒害,但其详细的分子机制有待进一步阐释。蓝氏贾第虫(Giardia lamblia)作为一种寄生性单细胞原生动物,进化地位特殊,对其NMD途径的研究有利于阐明基因表达调控的分子和进化机制。本研究通过酵母双杂交及体外pull-down实验分析了贾第虫NMD途径因子上游移码蛋白1(Giardia lamblia up-frameshift 1,GlUPF1)、贾第虫RNA结合蛋白(Giardia lamblia HRP1, GlHRP1)、贾第虫核糖核酸外切酶(Giardia lamblia Ski7p,GlSki7p、Giardia lamblia XRN1,GlXRN1)之间的相互作用关系。结果表明,GlUPF1全长与GlHRP1、GlXRN1(1~500 aa)、GlSki7p间均可发生相互作用。而且GlUPF1的CH结构域和C端结构域分别与GlHRP1、GlXRN1(1~500 aa)、GlSki7p相互作用。说明GlUPF1在贾第虫NMD途径中作为招募平台,在无义mRNA识别和降解过程中发挥重要作用。为此,结合本实验室之前的研究结果,我们提出原生动物贾第虫的NMD途径:在提前终止密码子处SURF(SMG1-UPF1-eRF1-eRF3)复合物形成后,GlUPF1被磷脂酰肌醇3-激酶(suppressor with morphogenetic effect on genitalia 1,SMG1)磷酸化修饰, NMD途径激活,随后GlUPF1与HRP1相互作用,将转录本标记为NMD底物;GlUPF1进而招募下游贾第虫5′-3′核糖核酸降解酶GlXRN1、贾第虫3′-5′ 核糖核酸降解因子GlSki7p,最终降解靶标mRNA。 相似文献
56.
57.
《Fungal biology》2022,126(8):480-487
Eutypa dieback and Esca are serious fungal grapevine trunk diseases (GTDs). Eutypa dieback is caused by Eutypa lata (Elata), and is often associated Phaeoacremonium minimum (Pmin), and Phaeomoniella chlamydospora (Pch) which are also important contributors to Esca disease.Understanding the complex pathogenesis mechanisms used by these causative fungi may potentially lead targeted treatments for GTDs in the future. Elata has been reported as a wood decay “soft rot” fungus and understanding of Elata’s pathogenesis chemistries can aid in controlling GTDs. Recent work that suggests that Pmin and Pch may contribute to pathogenesis by stimulating hydroxyl radical generation via secretion of low molecular weight phenolic metabolites. Building on these findings, we tested a hypothesis that antioxidants and chelators, and biocontrol agents that have been reported to secrete antioxidants and low molecular weight chelators, may inhibit the growth and activity of these fungi. Butylated hydroxy anisole (BHA) and butylated hydroxytoluene (BHT) were tested as antioxidant/chelators. BHA was found to be a highly effective control measure for the three pathogenic fungi tested at concentrations >0.5 mM. The biocontrol species Bacillus subtilis and Hypocrea (Trichoderma) atroviride were also tested, with both H. atroviride and B. subtilis effectively inhibiting growth of the three GTD fungi. 相似文献
58.
《Fungal Ecology》2022
Most Boletaceae form ectomycorrhizas but species in two sister groups (subfamily Chalciporoideae and the genus Pseudoboletus) have unclear trophic modes and are putatively mycoparasitic. Chalciporoideae is the earliest diverging lineage in Boletaceae and includes Chalciporus and Buchwaldoboletus. Buchwaldoboletus species fruit on wood and were thought to be saprobes, but the type species Buchwaldoboletus lignicola is mycoparasitic on the wood decay fungus Phaeolus schweinitzii. However, the nutritional mode and host range of B. lignicola and other Buchwaldoboletus remain unclear. We obtained fresh collections and axenic cultures of B. lignicola, B. hemichrysus and B. sphaerocephalus from the southeastern USA. We use cultures to examine the phylogenetic relationships among taxa in Chalciporoideae, elucidate the trophic mode of Buchwaldoboletus species and test the effect that Buchwaldoboletus species have on wood decay. Our analysis supports the hypothesis that the Chalciporus lineage is sister to all other Boletaceae but suggests that Buchwaldoboletus is not monophyletic. Confrontation experiments on agar suggest that Buchwaldoboletus species might parasitize a wide range of decay fungi. Buchwaldoboletus hemichrysus and B. sphaerocephalus produce abundant conidia in culture whereas the more distantly related B. lignicola produces sclerotia. Wood decay assays show that Buchwaldoboletus species did not have a significant effect on the decay caused by wood decay fungi. Interestingly, when B. lignicola or B. hemichrysus were inoculated alone on wood both species decayed wood, producing a brown rot that can cause 35–65% mass loss over 6 months. Our results suggest that Buchwaldoboletus species have a dual trophic mode as saprobes and mycoparasites. 相似文献
59.
Usherwood PN Davies TG Mellor IR O'Reilly AO Peng F Vais H Khambay BP Field LM Williamson MS 《FEBS letters》2007,581(28):5485-5492
Mutations in the DIIS4-S5 linker and DIIS5 have identified hotspots of pyrethroid and DDT interaction with the Drosophila para sodium channel. Wild-type and mutant channels were expressed in Xenopus oocytes and subjected to voltage-clamp analysis. Substitutions L914I, M918T, L925I, T929I and C933A decreased deltamethrin potency, M918T, L925I and T929I decreased permethrin potency and T929I, L925I and I936V decreased fenfluthrin potency. DDT potency was unaffected by M918T, but abolished by T929I and reduced by L925I, L932F and I936V, suggesting that DIIS5 contains at least part of the DDT binding domain. The data support a computer model of pyrethroid and DDT binding. 相似文献
60.
Wood decay under the microscope 总被引:3,自引:0,他引:3
Many aspects of the interactions between host wood structure and fungal activity can be revealed by high resolution light microscopy, and this technique has provided much of the information discussed here. A wide range of different types of decay can result from permutations of host species, fungal species and conditions within wood. Within this spectrum, three main types are commonly recognised: brown rot, white rot and soft rot. The present review explores parts of the range of variation that each of these encompasses and emphasizes that degradation modes appear to reflect a co-evolutionary adaptation of decay fungi to different wood species or the lignin composition within more primitive and advanced wood cell types. One objective of this review is to provide evidence that the terms brown rot, white rot and soft rot may not be obsolete, but rigid definitions for fungi that are placed into these categories may be less appropriate than thought previously. Detailed knowledge of decomposition processes does not only aid prognosis of decay development in living trees for hazard assessment but also allows the identification of wood decay fungi that can be used for biotechnology processes in the wood industry. In contrast to bacteria or commercial enzymes, hyphae can completely ramify through solid wood. In this review evidence is provided that wood decay fungi can effectively induce permeability changes in gymnospermous heartwood or can be applied to facilitate the identification of tree rings in diffuse porous wood of angiosperms. The specificity of their enzymes and the mild conditions under which degradation proceeds is partly detrimental for trees, but also make wood decay fungi potentially efficient biotechnological tools. 相似文献