126 research outputs found
Reply: Does the polyubiquitination pathway operate inside intact chloroplasts to remove proteins?
The ubiquitin-proteasome system (UPS) is the pre-eminent proteolytic system in eukaryotic cells. Its components are abundant in the cytosol and nucleus, and it selectively targets many proteins in both of these compartments for degradation. However, its functions are not restricted to nucleocytosolic proteins as it is now very well established that the UPS also targets proteins in organelles. For example, endoplasmic reticulum (ER) proteins are commonly degraded by the cytosolic proteasome following their extraction (or retrotranslocation) from the organelle, in a process termed ER-associated protein degradation (ERAD). In recent years, it has emerged that even proteins in endosymbiotic organelles (mitochondria and chloroplasts) are processed by ERAD-analogous systems. Ubiquitin-dependent degradation of chloroplast-resident proteins was initially described as a regulatory mechanism governing the chloroplast protein import machinery. This so called chloroplast-associated protein degradation (CHLORAD) system was assumed to act only at the surface of the organelle owing to the physical barrier presented by the double envelope membrane. However, recent results suggested that the UPS may have a more extensive role in regulating chloroplast proteins, affecting even those located internally. Though somewhat surprising, these results were not entirely unpredictable given that there are numerous historical reports suggesting ubiquitin action in chloroplasts, and there is increasing evidence that the UPS acts on internal mitochondrial proteins. We review the relevant literature, address corresponding criticisms, and present additional data supporting the possibility of UPS action inside chloroplasts
Composition and distribution of diatom assemblages in the surface sediments of the Bering Sea
Diatoms collected from the top 1 cm of the surface sediment layer at seven Bering Sea stations during the Fourth Chinese National Arctic Research Expedition (4th CHINARE-Arctic) in 2010 were studied. In total, 101 taxa belonging to 38 genera were found. The species were divided into four groups: eurythermal species, boreal-temperate species, polar species, and sea-ice species. The diatom assemblages at the stations in the southwestern basin area were primarily composed of boreal-temperate species, such as Neodenticula seminae, Thalassiosira trifulta, Rhizosolenia hebetata f. hiemalis, and Actinocyclus curvatulus. The northeastern shelf stations were dominated by polar species, including Fragilariopsis oceanica, Thalassiosira antarctica spora, Thalassiosira nordenskioeldii, and Thalassiosira hyalina. The overall abundance was highest at the basin stations with 3.7 ×106 cells∙g-1 of wet sediment, whereas the eastern shelf stations had the lowest abundance of 0.7×106 cells∙g-1 of wet sediment (excluding the resting spores of Chaetoceros spp.). The relationship between the distribution of the surface sediment diatom assemblages and the environment is discussed
A new species of Austrodecus Hodgson, 1907 (Arthropoda, Pycnogonida, Austrodecidae) from the Southwest Indian Ridge
A new species of pycnogonid collected by the Chinese research vessel R/V Dayangyihao during cruises to the Southwest Indian Ridge in 2008 and 2009 is recorded. The new species, Austrodecus bamberi, is placed into the tristanense-section by the characters of 4-articled ovigers and present auxiliary claws and is distinguished from other species in this section by the number and length of tubercles on the first coxae
Advances in Chinese Arctic and subarctic research in marine biology and ecology with emphasis on the Pacific Arctic sector
The Arctic is one of the most sensitive regions that respond through feedback to global climate changes. Climatic, hydrological and ecological changes in the Arctic are clear evidence of global warming. In 2012 and 2014, the 5th and 6th Chinese National Arctic Research Expeditions undertook studies in the Bering Sea, the Arctic Ocean (including the Chukchi Sea), and the Norwegian Sea. These studies provided us with a better understanding of the marine biology and ecology in the Arctic and subarctic regions, particularly in the Pacific Arctic sector. Rapid changes observed in the Arctic environment include the shrinking of cold-water masses in the Bering Sea in the summer, and elevated water temperatures promoting phytoplankton blooms, leading to an increase in phytoplankton transferred to higher trophic levels. As a result, the transfer efficiency of organic matter toward the bottom weakened, leading to a reduction in benthic biomass. This is consistent with expectations that the overall carbon and energy flux will ultimately switch from the dominant mode of sea ice–algae–benthos to one of phytoplankton–zooplankton. Influenced by Pacific water inflow, fluvial runoff and melting sea ice, the Chukchi Sea exhibited different responses to various environmental changes. Interactions between water masses led to other interannual ecological shifts. With the increase in sea ice melt and sunlight in the central region of the Arctic Ocean, the relative abundance of heterotrophic bacteria is expected to increase, and play a vital role in the Arctic microbial loop
Improving photosynthesis through multidisciplinary efforts: The next frontier of photosynthesis research
100 essential questions for the future of agriculture
Publication history: Accepted - 8 March 2023; Published online - 11 April 2023.The world is at a crossroad when it comes to agriculture. The global population is growing, and the demand for food is increasing, putting a strain on our agricultural resources and practices. To address this challenge, innovative, sustainable, and inclusive approaches to agriculture are urgently required. In this paper, we launched a call for Essential Questions for the Future of Agriculture and identified a priority list of 100 questions. We focus on 10 primary themes: transforming agri-food systems, enhancing resilience of agriculture to climate change, mitigating climate change through agriculture, exploring resources and technologies for breeding, advancing cultivation methods, sustaining healthy agroecosystems, enabling smart and controlled-environment agriculture for food security, promoting health and nutrition-driven agriculture, exploring economic opportunities and addressing social challenges, and integrating one health and modern agriculture. We emphasise the critical importance of interdisciplinary and multidisciplinary research that integrates both basic and applied sciences and bridges the gaps among various stakeholders for achieving sustainable agriculture.
Key points
Growing demand and resource limitations pose a critical challenge for agriculture, necessitating innovative and sustainable approaches.
The paper identifies 100 priority questions for the future of agriculture, indicating current and future research directions.
Sustainable agriculture depends on interdisciplinary and multidisciplinary research that harmonises basic and applied sciences and fosters collaboration among different stakeholders
The VQ Motif-Containing Protein Family of Plant-Specific Transcriptional Regulators
The VQ motif-containing proteins (designated as VQ proteins) are a class of plant-specific proteins with a conserved and single short FxxhVQxhTG amino acid sequence motif. VQ proteins regulate diverse developmental processes, including responses to biotic and abiotic stresses, seed development, and photomorphogenesis. In this Update, we summarize and discuss recent advances in our understanding of the regulation and function of VQ proteins and the role of the VQ motif in mediating transcriptional regulation and protein-protein interactions in signaling pathways. Based on the accumulated evidence, we propose a general mechanism of action for the VQ protein family, which likely defines a novel class of transcriptional regulators specific to plants
Arabidopsis FHY3/FAR1 Gene Family and Distinct Roles of Its Members in Light Control of Arabidopsis Development
FHY3 (far-red elongated hypocotyls 3) and FAR1 (far-red-impaired response) are two homologous proteins essential for phytochrome A controlled far-red responses in Arabidopsis (Arabidopsis thaliana). There are 12 additional FHY3/FAR1-related genes in the Arabidopsis genome. The predicted sizes of this family of proteins range from 531 amino acids to 851 amino acids, and they share 12.0% to 82.4% amino acid identities over their entire lengths. In addition, most FRS proteins contain one to three coiled-coil domains and one or two putative nuclear localization signals. Semiquantitative reverse transcription-polymerase chain reaction analyses revealed that all FRS genes except FRS10 are expressed in all tissues examined, including rosette leaves, cauline leaves, inflorescence stems, flowers, and siliques. Analyses of gene specific promoter∷GUS fusion reporter gene expression revealed that all FRS genes except FRS1 are expressed in hypocotyls, and their expression in hypocotyl is induced by far-red light treatment. Transient expression of green fluorescent protein tagged FRS fusion proteins in onion (Allium cepa) epidermal cells revealed that all FRS proteins are targeted into the nucleus. T-DNA knockout frs6 and frs8 mutants flowered early under both long-day and short-day conditions (with much more drastic effects under short-day conditions), suggesting that FRS6 and FRS8 regulate flowering time. In addition, FRS9 RNAi transgenic plants showed a specific hypersensitivity to red light inhibition of hypocotyl elongation and light-regulated gene expression, indicating that FRS9 is a specific negative regulator of phyB signaling mediating seedling deetiolation. In summary, our results support the notion that FRS family members play distinct roles in light control of Arabidopsis development, most likely by regulating nuclear gene expression
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