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991.
The parasitic plant Cuscuta campestris is dependent on its host for water, assimilates and amino acids. It can be controlled by the herbicide glyphosate, which inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), resulting in shikimate accumulation. In this study, C. campestris was parasitic on transgenic tobacco plants expressing green fluorescent protein (GFP) in the phloem. Changes in [14C]sucrose and GFP accumulation in the parasite were used as indicators of the herbicides effect on translocation between the host and parasite. Host plants were treated with glyphosate 22 days after sowing. Shikimate accumulation in the parasite 1 day after glyphosate treatment (DAGT) confirmed EPSPS inhibition in C. campestris. No damage was visible in the host plants for the first 3 DAGT, while during that same time, a significant reduction in [14C]sucrose and GFP accumulation was observed in the parasite. Thus, we propose that the parallel reduction in GFP and sucrose accumulation in C. campestris is a result of a glyphosate effect on the parasites ability to withdraw assimilates from the host.Abbreviations CLSM Confocal laser-scanning microscope - DAGT Days after glyphosate treatment - DAS Days after sowing - EPSPS 5-Enolpyruvylshikimate-3-phosphate synthase - GFP Green fluorescent protein 相似文献
992.
Potassium uptake and release in roots and translocation to the shoots were studied in 14-day-old winter wheat ( Tritictum aestivum L. cv. Martonvásári 8) of different K status. Transport processes were measured in the growth solutions for 5 h ensuring near-equilibrium conditions. The uptake showed three phases: (1) at low external K+ concentrations it increased with increasing concentrations and culminated at 0.1 m M : (2) between 0.1 and 1 m M it decreased, and (3) it increased again above 1 m M : The release of K+ showed a constant low level below 1 m M while paralleling the uptake above that. The uncoupler 2,4-dinitrophenol inhibited uptake phases (1) and (2), whereas it did not affect either phase (3) or K+ release. Translocation showed similar patterns. It is concluded that phases (1) and (2) depend on metabolic energy while phase (3) is mostly passive. It is emphasized that different types of regulation seem to operate in the transport mechanism: i.e. limitation by transport sites, control by negative feedback and by K+ /K+ exchange, respectively. 相似文献
993.
根据R基因保守区分离小麦R基因类似序列 总被引:3,自引:0,他引:3
用根据核苷酸结合位点(nucleotide binding site,NBS)和丝氨酸/苏氨酸蛋白质激酶域设计的2对简并性引物,以小麦-簇毛麦6VS/6AL易位系的cDNA为模板进行PCR扩增,扩增产物克隆到pGEM-T载体中,经测序,共获得具有NBS结构域特征的片段克隆9个和具有丝氨酸/苏氨酸蛋白质激酶域特征的片段的克隆1个。将克隆之间核苷酸序列同源性高于90%的克隆归为一类,把9个NBS片段分为6类。这6类抗病基因类似序列(resistance gene analogs,PGA)均具有阅读框,并与已克隆的小麦抗条锈病基因γr、大麦抗白粉病基因Mla1和Mla6、拟南芥的抗病基因RPS2以及其他一些抗病基因在NBS保守区内具有高度的同源性。用小麦中国春缺体-四体初步将它们分别定位于小麦第一、第二和第五部分同源群上,进一步用5′-RACE技术获得RGA N5的5′端,发现期编码产物的N端还具有6个亮氨酸拉链(leucine zipper,LZ),与RPS2的N-端有较高同源性。 相似文献
994.
Brianna Coulter Rebecca S. West Richard T. Kingsford Katherine E. Moseby 《Austral ecology》2023,48(7):1252-1273
The density and abundance of arid-dwelling taxa often change significantly in response to precipitation fluctuations and the abundance of their predators. The survival and density of burrowing arthropods and their burrows in arid environments following prolonged dry periods and subsequent rains is poorly understood, as is the potential influence of reintroductions of their predators, such as fossorial mammals. The persistence of these arthropods and their burrows may be important for other species that rely on them for food or use their burrows for shelter. In this study, we examined the density of burrowing and ground-nesting arthropods and their burrows in Australia's Strzelecki Desert over two years between 2019 and 2021. This period spanned the tail-end of the worst drought on record and subsequent drought-breaking rains. We employed a Before-After Control-Impact (BACI) study design to examine the short-term effects of a fossorial mammal reintroduction of the greater bilby (Macrotis lagotis) into predator-free fenced exclosures and used an inspection camera to detect the presence of spiders and other taxa within individually marked burrows. We observed the largest changes in arthropod abundance and burrow density between a period that encompassed a third consecutive summer in drought and the commencement of drought-breaking rains, with some taxa declining by as much as 77% (p < 0.001). While the density of harvester ant middens erupted over this time, the density of tarantulas, trapdoor spiders and scorpions declined significantly. The greater bilby reintroduction had no short-term effect on the densities of the arthropods or their burrows, but their arrival may have implications on their post-drought recovery. Further studies are needed to determine if the significant declines in arthropod populations and burrows are reflective of normal boom-bust population dynamics due to the poor natural history knowledge of the arthropods we examined. 相似文献
995.
Understanding adaptations to extreme weather events by endangered species is critical to inform conservation decisions, particularly when their adaptations relate to artificial habitat supplementation at translocation sites. Apnoea, temporary suspension of breathing, has been observed as an anti-predator adaptation by semi-aquatic reptiles that dive underwater for periods of time to avoid detection. This study reports on the observations of an endangered grassland skink, the pygmy bluetongue (Tiliqua adelaidensis), remaining submerged in rain-induced flooded artificial burrows at an experimental translocation site. 相似文献
996.
Kade D. Lazenby Peter S. Coates Shawn T. ONeil Michel T. Kohl David K. Dahlgren 《Ecology and evolution》2021,11(6):2741
Human enterprise has led to large‐scale changes in landscapes and altered wildlife population distribution and abundance, necessitating efficient and effective conservation strategies for impacted species. Greater sage‐grouse (Centrocercus urophasianus; hereafter sage‐grouse) are a widespread sagebrush (Artemisia spp.) obligate species that has experienced population declines since the mid‐1900s resulting from habitat loss and expansion of anthropogenic features into sagebrush ecosystems. Habitat loss is especially evident in North Dakota, USA, on the northeastern fringe of sage‐grouse’ distribution, where a remnant population remains despite recent development of energy‐related infrastructure. Resource managers in this region have determined a need to augment sage‐grouse populations using translocation techniques that can be important management tools for countering species decline from range contraction. Although translocations are a common tool for wildlife management, very little research has evaluated habitat following translocation, to track individual behaviors such as habitat selection and fidelity to the release site, which can help inform habitat requirements to guide selection of future release sites. We provide an example where locations from previously released radio‐marked sage‐grouse are used in a resource selection function framework to evaluate habitat selection following translocation and identify areas of seasonal habitat to inform habitat management and potential restoration needs. We also evaluated possible changes in seasonal habitat since the late 1980s using spatial data provided by the Rangeland Analysis Platform coupled with resource selection modeling results. Our results serve as critical baseline information for habitat used by translocated individuals across life stages in this study area, and will inform future evaluations of population performance and potential for long‐term recovery. 相似文献
997.
Ayesha I. T. Tulloch Valerie Hagger Aaron C. Greenville 《Global Change Biology》2020,26(10):5816-5828
Ecosystems are being altered by rapid and interacting changes in natural processes and anthropogenic threats to biodiversity. Uncertainty in historical, current and future effectiveness of actions hampers decisions about how to mitigate changes to prevent biodiversity loss and species extinctions. Research in resource management, agriculture and health indicates that forecasts predicting the effects of near‐term or seasonal environmental conditions on management greatly improve outcomes. Such forecasts help resolve uncertainties about when and how to operationalize management. We reviewed the scientific literature on environmental management to investigate whether near‐term forecasts are developed to inform biodiversity decisions in Australia, a nation with one of the highest recent extinction rates across the globe. We found that forecasts focused on economic objectives (e.g. fisheries management) predict on significantly shorter timelines and answer a broader range of management questions than forecasts focused on biodiversity conservation. We then evaluated scientific literature on the effectiveness of 484 actions to manage seven major terrestrial threats in Australia, to identify opportunities for near‐term forecasts to inform operational conservation decisions. Depending on the action, between 30% and 80% threat management operations experienced near‐term weather impacts on outcomes before, during or after management. Disease control, species translocation/reintroduction and habitat restoration actions were most frequently impacted, and negative impacts such as increased species mortality and reduced recruitment were more likely than positive impacts. Drought or dry conditions, and rainfall, were the most frequently reported weather impacts, indicating that near‐term forecasts predicting the effects of low or excessive rainfall on management outcomes are likely to have the greatest benefits. Across the world, many regions are, like Australia, becoming warmer and drier, or experiencing more extreme rainfall events. Informing conservation decisions with near‐term and seasonal ecological forecasting will be critical to harness uncertainties and lower the risk of threat management failure under global change. 相似文献
998.
999.
1000.
BECN1 is involved in the initiation of mitophagy: It facilitates PARK2 translocation to mitochondria
Vinay Choubey Michal Cagalinec Joanna Liiv Dzhamilja Safiulina Miriam A Hickey Malle Kuum Mailis Liiv Tahira Anwar Eeva-Liisa Eskelinen Allen Kaasik 《Autophagy》2014,10(6):1105-1119
The autophagy protein BECN1/Beclin 1 is known to play a central role in autophagosome formation and maturation. The results presented here demonstrate that BECN1 interacts with the Parkinson disease-related protein PARK2. This interaction does not require PARK2 translocation to mitochondria and occurs mostly in cytosol. However, our results suggest that BECN1 is involved in PARK2 translocation to mitochondria because loss of BECN1 inhibits CCCP- or PINK1 overexpression-induced PARK2 translocation. Our results also demonstrate that the observed PARK2-BECN1 interaction is functionally important. Measurements of the level of MFN2 (mitofusin 2), a PARK2 substrate, demonstrate that depletion of BECN1 prevents PARK2 translocation-induced MFN2 ubiquitination and loss. BECN1 depletion also rescues the MFN2 loss-induced suppression of mitochondrial fusion. In sum, our results demonstrate that BECN1 interacts with PARK2 and regulates PARK2 translocation to mitochondria as well as PARK2-induced mitophagy prior to autophagosome formation. 相似文献