Unearthing new ccr genes and SCC elements in staphylococci through genome mining.

The SCCmec typing is crucial for investigating methicillin-resistant S. aureus, relying primarily on the combination of ccr and mec gene complexes. To date, 19 ccr genes and 10 ccr gene complexes have been identified, forming 15 SCCmec types. With the vast release of bacterial genome sequences, mining the database for novel ccr gene complexes and SCC/SCCmec elements could enhance MRSA epidemiological studies. In this study, we identified 12 novel ccr genes (6 ccrA, 3 ccrB and 3 ccrC) through mining of the NCBI database, which forming 12 novel ccr gene complexes and 10 novel SCC elements. Overexpression of five groups of novel Ccr recombinases (CcrA9B3, CcrA10B1, CcrC3, CcrC4, and CcrC5) in a mutant MRSA strain lacking the ccr gene and extrachromosomal circular intermediate (ciSCC) production significantly promoted ciSCC production, demonstrating their biological activity. This discovery provides an opportunity to advance MRSA epidemiological research and develop database-based bacterial typing methods.

Novel cassette chromosome recombinases CcrA8B9 catalyse the excision and integration of the staphylococcal cassette chromosome mec element.

OBJECTIVES: A defining feature of MRSA is the SCCmec element. The excision and integration of SCCmec elements are catalysed by Ccr recombinases. Currently, seven ccrA, eight ccrB and two ccrC allotypes have been described. However, there have been no recent reports of a novel Ccr recombinase and thus this area should be explored. METHODS: According to the proposed criteria of the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) committee, novel ccr genes were explored by searching the genome of our laboratory staphylococcal strains, which were isolated from bovine mastitis in Northwest China. The biological activity of the novel Ccr recombinases to excise and integrate SCCmec elements was determined. The distribution of the novel ccr genes in staphylococci was conducted by querying the NCBI nr/nt database. RESULTS: We report a set of novel Ccr recombinases CcrA8B9, which share nucleotide identities of 46.6%-50.2% and 47.4%-52.8% with the ccrA and ccrB alleles, respectively. We used PCR to show that CcrA8B9 can excise and integrate the SCCmec element. Furthermore, using NCBI BLAST we showed that the ccrA8B9 genes exist in other staphylococcal strains. Unlike the common ccr genes, ccrA8B9 is located outside the SCCmec/SCC element. CONCLUSIONS: The novel Ccr recombinases CcrA8B9 can help excise and integrate SCCmec/SCC from the genome and provide a new way to facilitate the transmission of SCCmec/SCC elements among staphylococci.

A critical thermal transition driving spring phenology of Northern Hemisphere conifers.

Despite growing interest in predicting plant phenological shifts, advanced spring phenology by global climate change remains debated. Evidence documenting either small or large advancement of spring phenology to rising temperature over the spatio-temporal scales implies a potential existence of a thermal threshold in the responses of forests to global warming. We collected a unique data set of xylem cell-wall-thickening onset dates in 20 coniferous species covering a broad mean annual temperature (MAT) gradient (-3.05 to 22.9°C) across the Northern Hemisphere (latitudes 23°-66° N). Along the MAT gradient, we identified a threshold temperature (using segmented regression) of 4.9 ± 1.1°C, above which the response of xylem phenology to rising temperatures significantly decline. This threshold separates the Northern Hemisphere conifers into cold and warm thermal niches, with MAT and spring forcing being the primary drivers for the onset dates (estimated by linear and Bayesian mixed-effect models), respectively. The identified thermal threshold should be integrated into the Earth-System-Models for a better understanding of spring phenology in response to global warming and an improved prediction of global climate-carbon feedbacks.

Acceleration of Photocatalytic CO2 Reduction at Intimate Interface in AgBr/BiOBr Heterojunctions via a Co-anion Strategy.

Constructing heterojunctions with strong interfacial interactions can accelerate the transfer and separation of photogenerated charge carriers. However, finding a simple strategy to construct tightly connected heterojunctions remains a major challenge. In this work, AgBr/BiOBr S-scheme heterojunctions were designed via a straightforward co-anionic strategy without using a solvent. The experimental results indicate that the AgBr/BiOBr heterojunction with a close contact interface can extend the use of visible light, accelerate the separation, and induce the transfer of photoelectrons and holes while maintaining an excellent redox capacity. Undoubtedly, the photocatalytic reduction rate of carbon dioxide to carbon monoxide by 1.0 AgBr/BiOBr is 87.73 µmol·g-1·h-1 (quantum efficiency is 0.57%), which is 12.15 times and 4.45 times higher than that of pure AgBr and BiOBr, respectively. The present work provides insights into a simple strategy for the preparation of strongly interacting interfacial heterojunctions for photocatalytic CO2 reduction.

A profitable function of Ceriporia lacerata HG2011 on nodulation and biological nitrogen fixation of green bean (Phaseolus vulgaris L.).

AIMS: Green bean (Phaseolus vulgaris L.) is a popular vegetable worldwide. The use of beneficial fungi is a simple and effective way to improve the biological nitrogen fixation (BNF) of this leguminous vegetable. METHODS AND RESULTS: A micro-plot was conducted to investigate the enhancement of BNF using 15N natural abundance technology and agronomic performances of green bean caused by wood-rot fungus Ceriporia lacerata HG2011. The results showed the soil for frequently growing green bean featured abundant native rhizobia, and newly inoculated rhizobia may have to compete with them in nodulation and only highly competitive rhizobia can succeed. The addition of C. lacerata HG2011 to the soil increased the population of ammonia oxidizers, nitrifiers, and phosphorus (P)-mobilizing microbes in rhizosphere, accelerated nitrification and P mobilization, creating a favorable soil environment with high P and low ammonia for BNF. Green bean received C. lacerata HG2011 had higher dehydrogenase activity in roots and higher nodulation rate and large nodules. These phenomena implied abundant supplies of adenosine triphosphate, nicotinamide adenine dinucleotide hydrogen, or nicotinamide adenine dinucleotide phosphate hydrogen for BNF in the roots, a large proportion of N2 fixation tissues, and a greater sink for receiving photosynthates. As a result, C. lacerata HG2011 considerably increased the percentage of N derived from the atmosphere, BNF, and plant nutrient uptake (including N, P, and potassium), leading to 15.58%-28.51% of biomass increasment and 9.82%-17.03% of peapod yield increasment along with quality improvement compared with non-fungal application. CONCLUSIONS: C. lacerata HG2011 increased the nodulation and BNF of green bean, accelerated the nutrient uptake (NPK) and therefore improved the yield and peapod quality of green bean. SIGNIFICANCE AND IMPACT OF STUDY: The study demonstrates that C. lacerata HG2011 could be used as a biofertilizer for BNF improvement of legumes.

Photoperiod and temperature as dominant environmental drivers triggering secondary growth resumption in Northern Hemisphere conifers.

Wood formation consumes around 15% of the anthropogenic CO2 emissions per year and plays a critical role in long-term sequestration of carbon on Earth. However, the exogenous factors driving wood formation onset and the underlying cellular mechanisms are still poorly understood and quantified, and this hampers an effective assessment of terrestrial forest productivity and carbon budget under global warming. Here, we used an extensive collection of unique datasets of weekly xylem tissue formation (wood formation) from 21 coniferous species across the Northern Hemisphere (latitudes 23 to 67°N) to present a quantitative demonstration that the onset of wood formation in Northern Hemisphere conifers is primarily driven by photoperiod and mean annual temperature (MAT), and only secondarily by spring forcing, winter chilling, and moisture availability. Photoperiod interacts with MAT and plays the dominant role in regulating the onset of secondary meristem growth, contrary to its as-yet-unquantified role in affecting the springtime phenology of primary meristems. The unique relationships between exogenous factors and wood formation could help to predict how forest ecosystems respond and adapt to climate warming and could provide a better understanding of the feedback occurring between vegetation and climate that is mediated by phenology. Our study quantifies the role of major environmental drivers for incorporation into state-of-the-art Earth system models (ESMs), thereby providing an improved assessment of long-term and high-resolution observations of biogeochemical cycles across terrestrial biomes.

Application of Ceriporia lacerata HG2011 as biocontrol agent against multiple phytopathogenic fungi and oomycetes.

Overuse of fungicides to control crop diseases results in ecological damage, environmental pollution, and human health risks. Biocontrol is an increasingly popular alternative in plant disease management due to sustainability and environmental friendliness. Herein, antagonistic tests and greenhouse experiments were conducted to investigate the antagonism of a self-isolated white-rot fungus Ceriporia lacerata HG2011 against phytopathogens in vitro, the underlying mechanism exerted by this fungus, and disease control efficiency in the greenhouse. The results demonstrated that both soluble and volatile substances produced by this fungus suppressed the growth of all test phytopathogen fungi and oomycetes in vitro, with the inhibitory rates of 10.4-60.6% for soluble metabolites and 30.3-52.9% for volatiles. C. lacerata HG2011 could grow in and gradually spread on living phytopathogenic colonies, concurrently deformed and lysed pathogenic hyphae in dual culture, which were associated with the release of hydrolase (cellulose, chitinase, ß-glucanase, and protease) from this biocontrol fungus for the use of the pathogens as nutrient sources. The chitinolytic and cellulolytic production by C. lacerata HG2011 presents the specific response to the cell wall of pathogenic fungi and oomycetes, and ß-glucanase was triggered by carbon competition. Consequently, C. lacerata HG2011 successfully controlled eggplant stem blight and cucumber vine blight (control efficacy 67.9-70.9%) in the greenhouse experiments. C. lacerata HG2011 showed multiple antagonistic mechanisms against the phytopathogenic fungi and oomycetes concurrently. Our results provided information about a new potential use of this fungus as a biocontrol agent to control plant diseases in modern agriculture beyond medical purposes, wastewater treatment, and biofuel production.

Climate warming leads to advanced fruit development period of temperate woody species but divergent changes in its length.

Climate warming has significantly altered the phenology of plants in recent decades. However, in contrast to the widely reported warming-induced extension of vegetative growing season, the response of fruit development period (FDP) from flowering to fruiting remains largely unexplored, particularly for woody plants. Analyzing >560,000 in situ observations of both flowering and fruiting dates for six temperate woody species across 2958 European phenological observations sites during 1980-2013, we found that in all species both flowering and fruiting phenology, that is, the FDP, advanced with climate warming. However, the advancing rates of the two events were not necessarily equal for any given species, resulting in divergent changes in the length of FDP among species with climate warming. During 1980-2013, not only the temperature during FDP but also the forcing requirement for fruit development increased, both affecting the length of FDP. The shortened FDP was mainly due to elevated temperature, thus accelerating the accumulation of forcing, whereas the prolonged FDP was primarily caused by the substantial increase of the forcing requirement of fruiting, which could be fulfilled only in a longer time and thus slowed down the advance of fruiting. This study provides large-scale empirical evidence of warming-induced advances of FDP but divergent changes in its length in temperate woody species. Our findings demonstrate the contrasting reproductive phenological strategies among temperate woody species under the pressure of warming climate, contrary to the lengthening of vegetative growing season, which is by and largely similar with different woody species.

Ceriporia lacerata HG2011 enhances P mobilization and wheat agronomic performance irrespective of P fertilization levels.

AIMS: To identify soil phosphorus (P) mobilization and wheat agronomic performance in response to the P mobilizer Ceriporia lacerata HG2011 could provide a new strategy for improving fertilizer P efficiency in wheat cultivation. METHODS AND RESULTS: Liquid culture showed that C. lacerata HG2011 converted Ca3 (PO4 )2 , FePO4 , AlPO4 , phytate, lecithin and ribonucleic acid into soluble inorganic P, which was stimulated by ammonium and urea but less influenced by P supply. In the incubation experiment, this fungus colonized on wheat roots, and mobilized P in the soils regardless of Olsen P levels. The efflux of protons, organic acids and phosphatase could be involved in insoluble P mobilization. In the greenhouse pot experiment, C. lacerata HG2011 increased soil Olsen P under different P fertilization levels, improved wheat P uptake by 15.39%-28.70%, P fertilizer use efficiency by 4.26%-13.04% and grain yield by 12.24%-22.39%. CONCLUSIONS: Ceriporia lacerata HG2011 was able to colonize on wheat roots, mobilize P in soils and improve wheat agronomic performance irrespective of P fertilization levels. SIGNIFICANCE AND IMPACT OF THE STUDY: Ceriporia lacerata HG2011 could be used to enhance the quality of compost or as a bio-fertilizer for P mobilization in modern sustainable agriculture.

Characterization of a new Bacillus velezensis as a powerful biocontrol agent against tomato gray mold.

Biocontrol microbes are environment-friendly and safe for humans and animals. To seek biocontrol microbes effective in suppressing tomato gray mold is important for tomato production. Therefore, serial experiments were conducted to characterize the antagonism of Bacillus velezensis HY19, a novel self-isolated biocontrol bacterium, against Botrytis cinerea in vitro and the control on tomato gray mold in greenhouse. This bacterium produced extracellular phosphatase, protease, cellulose and siderophores, and considerably inhibited the growth of B. cinerea. A liquid chromatography-mass spectrometry (LC-MS) detected salicylic acid and numerous antifungal substances present in B. velezensis HY19 fermentation liquid (BVFL). When B. cinerea was grown on potato glucose agar, BVFL crude extract remarkably suppressed the fungal growth and reduced protein content and the activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD). Transcriptome studies showed that BVFL crude extract significantly induced different expression of numerous genes in B. cinerea, most of which were down-regulated. Theses differently expressed genes were involved in the biological process, cell compartment, molecular functions, and metabolisms of glycine, serine, threonine, and sulfur in pathogen hyphae. Thus, this biocontrol bacterium antagonized B. cinerea in multiple ways due to the production of numerous antifungal substances that acted on multiple targets in the cells. BVFL significantly increased antioxidant enzyme activities in tomato leaves and decreased the incidence of tomato gray mold, with the control efficacies of 73.12-76.51%. Taken together, B. velezensis HY19 showed a promising use potential as a powerful bioagent against tomato gray mold.

Phosphorus mobilization and improvement of crop agronomic performances by a new white-rot fungus Ceriporia lacerata HG2011.

BACKGROUND: Some soil microorganisms can mobilize unavailable phosphorus (P) in soils for plant use and increase P fertilizer efficiency. Thus, an abiotic P solubilization experiment and fungal incubation in solution and soil were conducted to investigate the mobilization of various P compounds by a new white-rot fungus Ceriporia lacerata HG2011. The crop agronomic performances were then evaluated in the winter barley-summer maize-winter wheat rotation field. RESULTS: Ceriporia lacerata HG2011 had a wide P mobilization spectrum and mobilized P by different mechanisms depending on P sources supplied in liquid culture. The chief mechanism employed by this fungus was the production of protons in mobilizing Ca3 (PO4 )2 , low-molecular-weight organic acids and other unknown substances in FePO4 and AlPO4 , phytase (an inducible enzyme in the presence of phytate) in phytate, and phosphatase in lecithin and ribonucleic acid, respectively. As a result of the large fungal biomass, P accumulated in the hypha should also be considered in the assessment of the fungal P mobilization, and not just only soluble inorganic P. As C. lacerata HG2011 colonized on and in the test soil, phosphatase and phytase activities were enhanced but pH decreased in the soil, leading to P mobilization. The application of this fungus mobilized soil P, increased crop P uptake and yields, and consecutively reduced P fertilizer use without yield sacrifices in the multiple crop rotation field. CONCLUSION: C. lacerata HG2011 showed a new use with respect to mobilizing soil P and reducing P fertilizer input in modern agriculture beyond medical purposes, environmental protection and biofuel production. © 2021 Society of Chemical Industry.

Topical Application of Tranexamic Acid Can Reduce Postoperative Blood Loss in Calcaneal Fractures: A Randomized Controlled Trial.

The traditional lateral "L" approach is common for managing calcaneal fractures with a drawback of significant blood loss. Yet there are no prospective studies on the hemostatic effect of the topical use of tranexamic acid (TXA) in calcaneal fracture surgeries. The purpose of this study was to evaluate the role of topical administration of TXA in reducing postoperative blood loss in calcaneal fractures. Forty participants were randomly distributed into the TXA group (n = 20) and the control group (n = 20). All participants underwent the same surgery via the lateral "L" approach. At the end of the operation, the surgical wound was irrigated with 80 mL 0.5 g/L TXA in the TXA group and 80 mL 0.9% sodium chloride in the control group, followed by the routine use of a drainage tube when closing the incision. Then, 20 mL 0.5 g/L TXA (TXA group) or 20 mL 0.9% sodium chloride solution (control group) was injected retrogradely into the wound through the drainage tube, which was clipped for 30 minutes thereafter. There were no significant differences in the baseline data between the 2 groups (p > .05). There was significantly less blood loss in the first 24 hours and total blood loss postoperation in the TXA group (p < .01). The surgical wounds healed well after surgery in both groups with no complication. We concluded that topical application of TXA in calcaneal fracture surgeries is a safe and useful method that can reduce postoperative blood loss.

Cellulose-Derived Hierarchical g-C3N4/TiO2-Nanotube Heterostructured Composites with Enhanced Visible-Light Photocatalytic Performance.

A novel cellulose-derived hierarchical g-C3N4/TiO2-nanotube heterostructured nanocomposite was fabricated by in situ coating thin g-C3N4 layers onto the surfaces of the TiO2 nanotubes, which were synthesized by utilizing the natural cellulose substance (e.g., commercial ordinary filter paper) as the structural template. These g-C3N4/TiO2-nanotube composites with varied thicknesses (ca. 3-30 nm) of the outer g-C3N4 layers displayed improved visible-light (λ > 420 nm)-driven photocatalytic degradation performances toward methylene blue. The optimal nanocomposite with an outer g-C3N4 layer of ca. 7.5 nm composed of 46 wt % g-C3N4 displayed an apparent rate constant of 0.0035 min-1, which was 8.5- and 4-fold larger than those of the referential TiO2-nanotube and g-C3N4 powder. The excellent and durable photocatalytic activities of these cellulose-derived g-C3N4/TiO2-nanotube composites were ascribed to their hierarchically network porous structures replicated from the cellulose template, as well as the formation of close heterojunctions in-between the g-C3N4 and TiO2 phases. Moreover, it was demonstrated that the photocatalytic mechanism matched with the type-II heterostructured model, while the main effective species during the photocatalytic processes of the nanocomposite were proved to be superoxide radicals.

Natural Cellulose Derived Nanocomposites as Anodic Materials for Lithium-Ion Batteries.

Bio-inspired synthetic method provides an effective shortcut to fabricate functional nanostructured materials with specific morphologies and designed functionalities. Natural cellulose substances (e. g., commercial laboratory cellulose filter paper) possesses unique three-dimensionally cross-linked porous structures and abundant functional groups for the functional modification on the surfaces. The deposition of metal oxide gel film on the surfaces of the cellulose nanofibers is facilely to be achieved through the surface sol-gel process, resulting in metal oxide replicas of the initial cellulose substance or metal-oxide/carbon nanocomposites. Moreover, the as-deposited metal oxide gel films coated on the cellulose fiber surfaces provide ideal platforms for the further formation of specific functional assemblies, and eventually to the corresponding nanocomposite materials. Based on this methodology, various nanostructured composites were prepared and employed as anodic materials for lithium-ion batteries, including metal-oxides-based (such as SnO2 , TiO2 , MoO3 , Fex Oy , and SiO2 ) and Si-based composites, as summarized in this personal account. Benefiting from the unique hierarchically porous network structures and the synergistic effects among the composite components of the anodic materials, the transfer of electrons/ions is accelerated and the structural stability of the electrode is enhanced, leading to the improved lithium storage performances and promoted cycling stability.

Divergent trends in the risk of spring frost damage to trees in Europe with recent warming.

Frost events during the active growth period of plants can cause extensive frost damage with tremendous economic losses and dramatic ecological consequences. A common assumption is that climate warming may bring along a reduction in the frequency and severity of frost damage to vegetation. On the other hand, it has been argued that rising temperature in late winter and early spring might trigger the so called "false spring", that is, early onset of growth that is followed by cold spells, resulting in increased frost damage. By combining daily gridded climate data and 1,489 k in situ phenological observations of 27 tree species from 5,565 phenological observation sites in Europe, we show here that temporal changes in the risk of spring frost damage with recent warming vary largely depending on the species and geographical locations. Species whose phenology was especially sensitive to climate warming tended to have increased risk of frost damage. Geographically, compared with continental areas, maritime and coastal areas in Europe were more exposed to increasing occurrence of frost and these late spring frosts were getting more severe in the maritime and coastal areas. Our results suggest that even though temperatures will be elevated in the future, some phenologically responsive species and many populations of a given species will paradoxically experience more frost damage in the future warming climate. More attention should be paid to the increased frost damage in responsive species and populations in maritime areas when developing strategies to mitigate the potential negative impacts of climate change on ecosystems in the near future.

Long-term changes in the impacts of global warming on leaf phenology of four temperate tree species.

Contrary to the generally advanced spring leaf unfolding under global warming, the effects of the climate warming on autumn leaf senescence are highly variable with advanced, delayed, and unchanged patterns being all reported. Using one million records of leaf phenology from four dominant temperate species in Europe, we investigated the temperature sensitivities of spring leaf unfolding and autumn leaf senescence (ST , advanced or delayed days per degree Celsius). The ST of spring phenology in all of the four examined species showed an increase and decrease during 1951-1980 and 1981-2013, respectively. The decrease in the ST during 1981-2013 appears to be caused by reduced accumulation of chilling units. As with spring phenology, the ST of leaf senescence of early successional and exotic species started to decline since 1980. In contrast, for late successional species, the ST of autumn senescence showed an increase for the entire study period from 1951 to 2013. Moreover, the impacts of rising temperature associated with global warming on spring leaf unfolding were stronger than those on autumn leaf senescence. The timing of leaf senescence was positively correlated with the timing of leaf unfolding during 1951-1980. However, as climate warming continued, the differences in the responses between spring and autumn phenology gradually increased, so that the correlation was no more significant during 1981-2013. Our results further suggest that since 2000, due to the decreased temperature sensitivity of leaf unfolding the length of the growing season has not increased any more. These finding needs to be addressed in vegetation models used for assessing the effects of climate change.

Chilling and forcing temperatures interact to predict the onset of wood formation in Northern Hemisphere conifers.

The phenology of wood formation is a critical process to consider for predicting how trees from the temperate and boreal zones may react to climate change. Compared to leaf phenology, however, the determinism of wood phenology is still poorly known. Here, we compared for the first time three alternative ecophysiological model classes (threshold models, heat-sum models and chilling-influenced heat-sum models) and an empirical model in their ability to predict the starting date of xylem cell enlargement in spring, for four major Northern Hemisphere conifers (Larix decidua, Pinus sylvestris, Picea abies and Picea mariana). We fitted models with Bayesian inference to wood phenological data collected for 220 site-years over Europe and Canada. The chilling-influenced heat-sum model received most support for all the four studied species, predicting validation data with a 7.7-day error, which is within one day of the observed data resolution. We conclude that both chilling and forcing temperatures determine the onset of wood formation in Northern Hemisphere conifers. Importantly, the chilling-influenced heat-sum model showed virtually no spatial bias whichever the species, despite the large environmental gradients considered. This suggests that the spring onset of wood formation is far less affected by local adaptation than by environmentally driven plasticity. In a context of climate change, we therefore expect rising winter-spring temperature to exert ambivalent effects on the spring onset of wood formation, tending to hasten it through the accumulation of forcing temperature, but imposing a higher forcing temperature requirement through the lower accumulation of chilling.

Responses of bud-break phenology to daily-asymmetric warming: daytime warming intensifies the advancement of bud break.

There is evidence that the ongoing climate change is happening through nighttime rather than daytime warming. How such a daily-asymmetric warming modifies plant phenology is still unclear. We investigated the effects of asymmetric warming on bud break by daily monitoring seedlings belonging to 26 black spruce [Picea mariana (Mill.) BSP.] and 15 balsam fir [Abies balsamea (L.) Mill.] provenances from the native range in Canada. Seedlings were subjected to either daytime or nighttime warming in three growth chambers at temperatures ranging between 10 and 24 °C. On average, a warming of 4 °C advanced the timings of bud break in both species by 2.4 days, with the later phases being more sensitive to the treatment. Bud break of both species responded more strongly to daytime warming, with the bud break occurred 1.2 and 3.2 days earlier under daytime than nighttime warming in black spruce and balsam fir, respectively. A marked ecotypic differentiation was only observed in black spruce that originated from provenances distributed broadly across Canada, with seedlings from the warmest provenance completing bud break 8.3 days later than those from the coldest one. However, no significant effect of provenance was observed for balsam fir, the narrowly distributed species. Overall, the above results suggest that a higher temporal resolution such as temperatures during daytime and nighttime, and higher spatial resolution should be taken into account to improve the accuracy of phenological model predictions under global change scenarios. Phenological models based on daily average temperature should take into account the diverging impacts of asymmetric warming on plant phenology. Our findings may indicate that the influence of warming on plant phenology may be less dramatic than expected.

[Effect of different fertilization treatments on growth,secondary metabolites,and seed yield and quality of Perilla frutescens].

Perilla frutescens,an annual plant in Labiatae family,is grown throughout China and can be used for medicine purposes and as food additives. The present field experiment was carried out to study the effects of different fertilizer treatments on the concentrations and accumulations of antioxidant components,including flavonoids and polyphenols,growth,seed yields and qualities of this plant.The main aim of this study is to provide farmers some advice for improving the yields and qualities of P. frutescens in theory and practice.Five treatments were set up,including a no fertilizer control(CK),chemical fertilizers(CF),organic fertilizers(M),organic fertilizers plus chemical fertilizers at the rates of 1 ∶1 and 1 ∶3 in terms of nitrogen(50 M,25 M). Plant growth parameters were recorded and total flavonoids and polyphenols were determined in three key growth stages of P. frutescens. At the fast growth period,samples of roots,leaves,and stems were collected for determining a total of flavonoids and polyphenols as well as DPPH removal rate of ethanol extracts. Seed yields and qualities were also recorded at harvest. The results showed fertilization enhanced growth and seed yields although no significant difference was observed in growth and seed yields in inorganic-organic fertilizer treatments. The total flavonoids,polyphenols,and DPPH removal rate of ethanol extracts followed the sequence leaves>stems>roots,indicating synthesis of these metabolites in the leaves. DPPH removal rate showed a positive linear correlation with total flavonoid and polyphenol concentrations. In addition,organic-inorganic fertilization significantly increased the numbers of both effective panicles and paniclegrains. Fertilizer treatments had no effect on seed qualities of P. frutescens,while 50 M achieved the highest yield,which increased by 14. 73% compared to CF alone. In general,50 M increased antioxidant components,biomass,and seed yield of P. frutescens,meriting advocate in cultivation.

Spring phenology at different altitudes is becoming more uniform under global warming in Europe.

Under current global warming, high-elevation regions are expected to experience faster warming than low-elevation regions. However, due to the lack of studies based on long-term large-scale data, the relationship between tree spring phenology and the elevation-dependent warming is unclear. Using 652k records of leaf unfolding of five temperate tree species monitored during 1951-2013 in situ in Europe, we discovered a nonlinear trend in the altitudinal sensitivity (SA , shifted days per 100 m in altitude) in spring phenology. A delayed leaf unfolding (2.7 ± 0.6 days per decade) was observed at high elevations possibly due to decreased spring forcing between 1951 and 1980. The delayed leaf unfolding at high-elevation regions was companied by a simultaneous advancing of leaf unfolding at low elevations. These divergent trends contributed to a significant increase in the SA (0.36 ± 0.07 days 100/m per decade) during 1951-1980. Since 1980, the SA started to decline with a rate of -0.32 ± 0.07 days 100/m per decade, possibly due to reduced chilling at low elevations and improved efficiency of spring forcing in advancing the leaf unfolding at high elevations, the latter being caused by increased chilling. Our results suggest that due to both different temperature changes at the different altitudes, and the different tree responses to these changes, the tree phenology has shifted at different rates leading to a more uniform phenology at different altitudes during recent decades.