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Identifying seasonal differences in migration characteristics of Oriental white stork (Ciconia boyciana) through satellite tracking and remote sensing
No full textMigratory species interact with different ecosystems in different regions during migration, making them more environmentally sensitive and therefore more vulnerable to extinction. Long migration routes and limited con-servation resources desire clear identification of conservation priorities to improve the allocation efficiency of conservation resources. Clarifying the spatio-temporal heterogeneity of the utilization intensity during migration is an effective way to guide the conservation areas and priority. 12 Oriental White Storks (Ciconia boyciana), listed as an endangered species by the IUCN, were equipped with satellite-tracking loggers to record their hourly location throughout the year. Then, combined with remote sensing and dynamic Brownian Bridge Movement Model (dBBMM), characteristics and differences between spring and autumn migration were iden-tified and compared. Our findings revealed that: (1) the Bohai Rim has always been the core stopover area for the Storks' spring and autumn migration, but the utilization intensity has spatial differences; (2) differences in habitat selection resulted in differences in the Storks' spatial distribution, thus affecting the efficiency of existing conservation systems; (3) the shift of habitat from natural wetlands to artificial surfaces calls for the development of eco-friendly land use mode; (4) the development of satellite tracking, remote sensing, and advanced data analysis methods have greatly facilitated movement ecology, even though they are still under development
Precipitation consistently promotes, but temperature inversely drives, biomass production in temperate vs. alpine grasslands
No full textComparisons of vegetation production between temperate and alpine grasslands are not well studied, and the understanding of the underlying mechanisms is still incomplete. To address this issue, we selected the Inner Mongolia and Tibet regions to conduct large-transect surveys for temperate grassland (TG) and alpine grassland (AG), respectively, in China, to reveal the universal and differential mechanisms of above-and belowground biomass production (GB, AGB and BGB) and precipitation use efficiencies (PUE) in the two grasslands. The relative importance of climatic factors on biomass and PUE is greater than that of soil and biological factors. Elevated mean annual precipitation (MAP) consistently increased GB in both TG and AG. Increased mean annual temperature (MAT) reduced GB by weakening the soil nutrient status in TG, whereas it increased GB by improving the soil nutrient status in AG. MAP promoted more AGB than BGB in TG, whereas MAT affected BGB more than AGB in AG. When the multicomponent heterogeneity of other factors in grasslands was eliminated, the effect of MAP on GB remained significant for both TG and AG. After removing the effect of multifactorial het-erogeneity, however, the significant effect of MAP on PUE of the two grasslands was largely enhanced. From these results, we can conclude that climatic factors do not always exert identical effects on different grasslands. In particular, highlighting the divergent mechanisms of biomass production and precipitation use efficiency between temperate and alpine grasslands can improve the understanding of the carbon sink and hydraulic sensitivity of various grasslands
Soil Acidification Under Long-Term N Addition Decreases the Diversity of Soil Bacteria and Fungi and Changes Their Community Composition in a Semiarid Grassland
No full textSoil microorganisms play key roles in terrestrial biogeochemical cycles and ecosystem functions. However, few studies address how long-term nitrogen (N) addition gradients impact soil bacterial and fungal diversity and community composition simultaneously. Here, we investigated soil bacterial and fungal diversity and community composition based on a long-term (17 years) N addition gradient experiment (six levels: 0, 2, 4, 8, 16, 32 gN m(-2) year(-1)) in temperate grassland, using the high-throughput Illumina MiSeq sequencing. Results showed that both soil bacterial and fungal alpha diversity responded nonlinearly to the N input gradient and reduced drastically when the N addition rate reached 32 g N m(-2) year(-1). The relative abundance of soil bacterial phyla Proteobacteria increased and Acidobacteria decreased significantly with increasing N level. In addition, the relative abundance of bacterial functional groups associated with aerobic ammonia oxidation, aerobic nitrite oxidation, nitrification, respiration of sulfate and sulfur compounds, and chitinolysis significantly decreased under the highest N addition treatment. For soil fungi, the relative abundance of Ascomycota increased linearly along the N enrichment gradient. These results suggest that changes in soil microbial community composition under elevated N do not always support the copiotrophic-oligotrophic hypothesis, and some certain functional bacteria would not simply be controlled by soil nutrients. Further analysis illustrated that reduced soil pH under N addition was the main factor driving variations in soil microbial diversity and community structure in this grassland. Our findings highlight the consistently nonlinear responses of soil bacterial and fungal diversity to increasing N input and the significant effects of soil acidification on soil microbial communities, which can be helpful for the prediction of underground ecosystem processes in light of future rising N deposition
Cryo-electron microscopy structure of the intact photosynthetic light-harvesting antenna-reaction center complex from a green sulfur bacterium
No full textThe photosynthetic reaction center complex (RCC) of green sulfur bacteria (GSB) consists of the membrane-imbedded RC core and the peripheric energy transmitting proteins called Fenna-Matthews-Olson (FMO). Functionally, FMO transfers the absorbed energy from a huge peripheral light-harvesting antenna named chlorosome to the RC core where charge separation occurs. In vivo, one RC was found to bind two FMOs, however, the intact structure of RCC as well as the energy transfer mechanism within RCC remain to be clarified. Here we report a structure of intact RCC which contains a RC core and two FMO trimers from a thermophilic green sulfur bacterium Chlorobaculum tepidum at 2.9 angstrom resolution by cryo-electron microscopy. The second FMO trimer is attached at the cytoplasmic side asymmetrically relative to the first FMO trimer reported previously. We also observed two new subunits (PscE and PscF) and the N-terminal transmembrane domain of a cytochrome-containing subunit (PscC) in the structure. These two novel subunits possibly function to facilitate the binding of FMOs to RC core and to stabilize the whole complex. A new bacteriochlorophyll (numbered as 816) was identified at the interspace between PscF and PscA-1, causing an asymmetrical energy transfer from the two FMO trimers to RC core. Based on the structure, we propose an energy transfer network within this photosynthetic apparatus
A dynamic phosphoproteomic analysis provides insight into the C4 plant maize (Zea mays L.) response to natural diurnal changes
No full textAs sessile organisms, plants need to respond to rapid changes in numerous environmental factors, mainly diurnal changes of light, temperature, and humidity. Maize is the world's most grown crop, and as a C4 plant it exhibits high photosynthesis capacity, reaching the highest rate of net photosynthesis at midday; that is, there is no midday depression. Revealing the physiological responses to diurnal changes and underlying mechanisms will be of great significance for guiding maize improvement efforts. In this study, we collected maize leaf samples and analyzed the proteome and phosphoproteome at nine time points during a single day/night cycle, quantifying 7424 proteins and 5361 phosphosites. The new phosphosites identified in our study increased the total maize phosphoproteome coverage by 8.5%. Kinase-substrate network analysis indicated that 997 potential substrates were phosphorylated by 20 activated kinases. Through analysis of proteins with significant changes in abundance and phosphorylation, we found that the response to a heat stimulus involves a change in the abundance of numerous proteins. By contrast, the high light at noon and rapidly changing light conditions induced changes in the phosphorylation level of proteins involved in processes such as chloroplast movement, photosynthesis, and C4 pathways. Phosphorylation is involved in regulating the activity of large number of enzymes; for example, phosphorylation of S55 significantly enhanced the activity of maize phosphoenolpyruvate carboxykinase1 (ZmPEPCK1). Overall, the database of dynamic protein abundance and phosphorylation we have generated provides a resource for the improvement of C4 crop plants
Correction: Essential oils from two aromatic plants repel the tobacco whitefly Bemisia tabaci (vol 95, pg 971, 2022)
No full textElevated ozone decreases the multifunctionality of belowground ecosystems
No full textElevated tropospheric ozone (O-3) affects the allocation of biomass aboveground and belowground and influences terrestrial ecosystem functions. However, how belowground functions respond to elevated O-3 concentrations ([O-3]) remains unclear at the global scale. Here, we conducted a detailed synthesis of belowground functioning responses to elevated [O-3] by performing a meta-analysis of 2395 paired observations from 222 publications. We found that elevated [O-3] significantly reduced the primary productivity of roots by 19.8%, 16.3%, and 26.9% for crops, trees and grasses, respectively. Elevated [O-3] strongly decreased the root/shoot ratio by 11.3% for crops and by 4.9% for trees, which indicated that roots were highly sensitive to O-3. Elevated [O-3] impacted carbon and nitrogen cycling in croplands, as evidenced by decreased dissolved organic carbon, microbial biomass carbon, total soil nitrogen, ammonium nitrogen, microbial biomass nitrogen, and nitrification rates in association with increased nitrate nitrogen and denitrification rates. Elevated [O-3] significantly decreased fungal phospholipid fatty acids in croplands, which suggested that O-3 altered the microbial community and composition. The responses of belowground functions to elevated [O-3] were modified by experimental methods, root environments, and additional global change factors. Therefore, these factors should be considered to avoid the underestimation or overestimation of the impacts of elevated [O-3] on belowground functioning. The significant negative relationships between O-3-treated intensity and the multifunctionality index for croplands, forests, and grasslands implied that elevated [O-3] decreases belowground ecosystem multifunctionality
Decoupling of N and P aggravated upward along food chains in an urban river ecosystem
No full textAnthropogenic input of nutrient has profoundly influenced water quality and aquatic organisms, however, large and unbalanced nitrogen (N) and phosphorus (P) inputs (decoupling) can lead to a range of ecological health problems such as eutrophication. Whether and how the decoupling varies along the aquatic food chain remains poorly addressed. Here we chose an urban river ecosystem in the cosmopolis region of Beijing, with reclaimed water as the entire replenishment water source over 20 years, to demonstrate the decoupling pattern of N vs P across trophic levels. Results showed that organism C, N and P concentration increased, but N:P ratio decreased upward along the food chains, suggesting that this decoupling of N and P increased as trophic level ascends. Compared with natural freshwater ecosystem, the decoupling of N and P was aggravated in the reclaimed water river. Moreover, the homeostasis of N and P were higher at higher relative to lower trophic levels, and higher in macro-food chain relative to planktonic food chain. This study, for the first time, revealed the increasing decoupling of N vs P upward along the major food chains in an urban aquatic ecosystem, and could improve the understanding of nutrient cycling at the food chain level under human disturbance, and provide useful information for ecological restoration and eutrophication control of urban wetlands replenished with reclaimed water
Extensive regulation of pH-responsive transcription factor PacC on secondary metabolism contributes to development and virulence of Botrytis cinerea
No full textBotrytis cinerea is one of the most important postharvest pathogens and causes huge economic losses worldwide. Ambient pH is a critical factor influencing virulence of B. cinerea. In this study, BcpacC, a crucial gene encoding a pH-responsive transcription factor, was knocked out in B. cinerea strain B05.10. Deletion of BcpacC resulted in pH-dependent reduction in mycelial growth, sporulation, and virulence in apple and tomato fruit, and romaine lettuce leaves. An iTRAQ based proteomic analysis identified 70 differential proteins involved in various biological processes between wildtype (WT) and Delta BcpacC mutant under pH 6 condition, including 18 proteins related to secondary metabolism. Gene expression analysis indicates that 37 of all the 42 secondary metabolism key enzyme encoding genes were regulated by BcPacC. Further, three PacC-regulated polyketide synthase encoding genes, Bcpks4, Bcpks5 and Bcpks11, were knocked out and first proved to contribute to sporulation and virulence in B. cinerea. Our results revealed that the extensive regulation of BcPacC on secondary metabolism might play crucial roles in development and pathogenicity of B. cinerea during adaption to ambient pH
Cold-induced calreticulin OsCRT3 conformational changes promote OsCIPK7 binding and temperature sensing in rice
No full textUnusually low temperatures caused by global climate change adversely affect rice production. Sensing cold to trigger signal network is a key base for improvement of chilling tolerance trait. Here, we report that Oryza sativa Calreticulin 3 (OsCRT3) localized at the endoplasmic reticulum (ER) exhibits conformational changes under cold stress, thereby enhancing its interaction with CBL-interacting protein kinase 7 (OsCIPK7) to sense cold. Phenotypic analyses of OsCRT3 knock-out mutants and transgenic overexpression lines demonstrate that OsCRT3 is a positive regulator in chilling tolerance. OsCRT3 localizes at the ER and mediates increases in cytosolic calcium levels under cold stress. Notably, cold stress triggers secondary structural changes of OsCRT3 and enhances its binding affinity with OsCIPK7, which finally boosts its kinase activity. Moreover, Calcineurin B-like protein 7 (OsCBL7) and OsCBL8 interact with OsCIPK7 specifically on the plasma membrane. Taken together, our results thus identify a cold-sensing mechanism that simultaneously conveys cold-induced protein conformational change, enhances kinase activity, and Ca2+ signal generation to facilitate chilling tolerance in rice