Magnetic minerals are greatly influenced by soil forming factors and processes. Understanding the factors controlling magnetic mineral characteristics and their (trans)formation mechanisms in diverse environments is essential offering insights into pedogenesis and environmental changes. To investigate the main factors influencing magnetic characteristics and mineral (trans)formation in soil developed on slopes of a subtropical mountain in southeastern China, this study examined two mountain red earth profiles: the DYA profile on a shaded slope derived from tuff, and the DYB profile on a sunny slope derived from muscovite-bearing sandstone (MBSS). Both profiles were sampled at 10 cm intervals to a depth of 2.1 m, yielding 21 samples from each profile. The analysis integrated magnetic parameters with geochemical indicators, clay mineral assemblages, chemical selective dissolution of iron (Fe), physicochemical properties, and chromaticity indices. The ANOVA results indicated highly significant differences between magnetic parameters among tuff and MBSS-derived soils (p < 0.001). The Spearman correlations showed insignificant relationships between all magnetic parameters and most of the studied variables for soils formed on tuff, while in MBSS-derived soils most of magnetic parameters were significantly correlated with soil organic matter (SOM), pH, total Fe, free Fe (Fed), amorphous Fe (Feo), total ferrous (Fe2+), silica-Fe ratio, and clay content (p <0.05-< 0.001). These findings suggest that parent material and pedogenesis (i.e., degree of weathering) were the main factors influencing soil magnetism in the study area. In the DYA profile, an S-ratio exceeding 0.9, a remanent coercivity (Bcr) of 70-75 mT, and a distinct inflection point near 580 degrees C in the kappa-T curves, collectively indicate that magnetite dominates the magnetic properties. In the DYB profile, the values below the Ah horizon (S-ratio ti 0, Bcr > 200 mT, redness >12) are characteristic of hematite-controlled magnetism. In the topsoil, however, the marked changes (S-ratio > 0.5, Bcr < 50 mT, and percentage frequency-dependent susceptibility, chi fd% > 8%) suggest that hematite has been transformed into fine-grained magnetite through the reduction driven by SOM. Our research provides new insights into understanding of factors affecting magnetic properties and the (trans)formation mechanisms of magnetic minerals in soils of humid subtropical environment.

Although loess deposits have been globally mapped and extensively studied, current understanding of their distribution and paleoclimatic significance in Pakistan remain limited. In this study we identified and characterized loess deposits along the Indus River in Pakistan through systematic field work, sampling (top soils and loess sections) and multi-proxy measurements. Based on sedimentary features and bulk grain size distributions, we reveal that, in addition to the previously known loess in the northern highlands, loess deposits of varying thickness are widespread across the Indus Plain. Tentative stratigraphic correlation among three loess sections (TD, BH, ATT) and loess sections in the Kashmir Valley suggests that loess in the northern highlands was dated back to at least 300 ka, while on the Indus Plain, commenced around 60-25 ka (Marine Isotope Stage 3). Pakistani loess exhibits significant regional differences in bulk grain size, paleosol development, magnetic properties, and geochemical characteristics, likely influenced by factors such as the topography, dust sources, and hydrological conditions. The identification and characterization of these loess deposits advance paleoclimate reconstruction efforts, although future work is needed to refine chronology, identify dust sources, select appropriate proxies, and establish regional correlations.

Southwestern Iran occupies a climatically sensitive transition zone between mid-latitude westerlies and low-latitude monsoon systems, yet Holocene paleoclimate reconstructions from loess-paleosol archives remain limited. Here, we present a multi-proxy investigation of a well-preserved loess-paleosol sequence from the Shooshtar area to reconstruct regional climate evolution since 10.2 ka BP. Based on a Bayesian age-depth model constrained by three AMS 14C dates, grain-size distributions, magnetic properties, geochemical elemental ratios, and diffuse reflectance spectroscopy were systematically analyzed. The results reveal two distinct stages of Holocene climate evolution, separated by a major transition at ∼5 ka BP. The Early–Middle Holocene (∼10.2–5 ka BP) is characterized by intensified pedogenesis and increased effective moisture, whereas the Late Holocene is marked by reduced pedogenesis, enhanced aeolian activity, and progressive aridification. Regional comparisons indicate that this transition reflects a large-scale reorganization of atmospheric circulation across West Asia. The regional aridification trend since ∼5 ka is consistent with a decline in winter precipitation across the Mediterranean, which is primarily controlled by westerly-derived moisture supply, and contrasts with the contemporaneous humidification associated with the southwest monsoon. This pattern suggests that Late Holocene drying in the study region was more directly linked to reduced westerly-derived winter moisture. These results underscore the dominant role of westerly circulation in regulating hydroclimatic variability across the semi-arid margins of West Asia.

The Paleogene Period, recognized as a quintessential greenhouse climate interval in Earth's history characterized by elevated global temperatures and heightened atmospheric CO2 concentrations, has become a focal area in deep-time paleoclimate research. The current generation of paleoclimatic reconstructions for this interval remains largely constrained to orbital forcing regimes and tectonic-scale frameworks, resulting in a temporal resolution that is inadequate for effectively predicting future global climate change. The deep-time lacustrine varved sediments can record seasonal-to-annual scale paleoclimate information, demonstrating distinct advantages among various interannual paleoclimate proxies, making them ideal research materials for predicting future global climate change. The Nanxiong Basin (25 degrees 03'-25 degrees 16'N, 114 degrees 08'-114 degrees 40'E), located in southeastern China, has complete preservation of Late Cretaceous to Early Paleogene terrestrial strata. This basin has emerged as a hotspot for high-resolution paleoclimatic reconstruction due to its lithostratigraphic completeness and continuous cyclostratigraphic archives spanning the Cretaceous-Paleogene (K-Pg) transition. The terrestrial stratum is dominated lithologically by red silty mudstone and muddy siltstone. The Paleocene Guchengcun Formation in its northwestern sector hosts multiple layers of grayish-black mudstones with varying thicknesses, one of which preserves clear lamination structures. Current academic research demonstrates a paucity of investigations into the paleoclimatic conditions governing the genesis of these mudstones and associated laminations. In this study, high-resolution climate proxies were performed for this laminated sequence (optical microscope observation, EDS, and mu XRF), combined with spectral analysis to explore whether it is an annual varve and to reveal the paleoclimate information it records, particularly focusing on solar activity. The results show that: 1) the laminar structure exhibits distinct differences in color, mineral, and chemical composition. Through microscopic observation, it is found that the thickness of the layer pairs varies greatly. One type displays relatively thin couplets (0.3-0.5 mm) within the common thickness range. In contrast, the other type consists of a relatively thick light-colored layer and a dark-colored layer, with individual couplets reaching 3-4 mm thickness. Specifically, the content of endogenous lacustrine components such as carbonates and calcium (Ca) elements is higher in the light layer compared to the dark layer. Conversely, the concentration of extrinsic lacustrine components-including clay minerals, titanium (Ti) elements, and organic matter-is significantly greater in the dark layer than in the light layer; 2) Integrating paleoclimatic records, we propose that the differences between the light and dark layers primarily result from seasonal climate variations throughout the year, indicating that this laminated sequence represents a typical varve. The formation process is as follows: during the summer with more rainfall, a dark layer rich in exogenous debris and organic matter forms; conversely, in the dry and hot winter, intense evaporation leads to substantial carbonate precipitation, resulting in a light-colored layer; 3) The spectral analysis of Ti, Ca and a* value reveals four stable cycles, ranging from 0.20 to 0.46 mm,0.83 to 1.46 mm,2.00 to 4.60 mm, and 6.12 to 7.28 mm, of which 0.20 to 0. 46 mm is the thickness of the typical varve, and the latter three cycles may be associated with El Ni & ntilde;o-Southern Oscillation (ENSO), the 11-year Schwabe sunspot cycle and the 22-year Hale cycle. Solar activity regulates the climate of the study area through both "top-down" and "bottom-up" mechanisms. During years of high solar activity, precipitation increases along with increased exogenous inputs to the lakes; conversely, evaporation intensifies during low solar activity years while enhanced authigenic carbonate deposits are formed in the lake.

Moderate UV-B promotes plant growth, but excessive UV-B inhibits plant development. The induction mechanism of how CtWD40-6 responds to UV-B is still unclear in safflower. Our results showed that CtWD40-6 is expressed at the top of safflower leaves and is strongly induced by UV-B. To further understand the function of the CtWD40-6 gene, we overexpressed the CtWD40-6 gene in safflower or Arabidopsis. First, different transgenic materials were treated with UV-B, and we found that the survival rate of plants overexpressing CtWD40-6 was significantly higher than that of the WT type. In contrast, the survival rate of wd40-6 mutant plants was significantly decreased compared with WT type. Then DAB, NBT and Trypan Blue staining were performed on different transgenic plants before and after UV-B treatment and the results showed that the staining of mutant and WT was significantly higher than that of overexpressing CtWD40-6. By comparing the data before and after UV-B stress, we found that the flavonoid content, antioxidant enzyme activity, chlorophyll content and photosynthetic rate of transgenic plants overexpressing CtWD40-6 were higher than those of WT and mutants, thereby obtaining better UV-B tolerance. Finally, we used yeast two-hybrid and luciferase complementation experiments to prove that CtWD40-6 increases the content of safflower flavonoids by interacting with CtANS1/CtCHS1/Ct4CL1/CtFLS1, thereby enhancing the plant's UV-B tolerance. The above results provide a theoretical basis for preliminary analysis of how safflower responds to UV-B stress through the transcriptional regulation of CtWD40-6.

Hairy root cultures induced by Agrobacterium rhizogenes (Rhizobium rhizogenes) provide a sustainable approach to meet the growing demand for economically valuable plant-derived compounds in the face of depleting natural resources. These cultures exhibit rapid, hormone-independent growth and genetic stability, making them viable for producing bioactive compounds, plant-specialized metabolites, and recombinant proteins. However, challenges remain in optimizing large-scale production, improving bioreactor efficiency, and enhancing metabolite synthesis across different plant species. This review addresses these challenges by exploring the mechanisms behind the induction of hairy root cultures, their applications in genetic and metabolic engineering, and their potential in environmental remediation. The review further highlights recent advances in biotechnology and illustrates how the hairy root system can sustainably meet industrial, pharmaceutical, and agricultural needs. In addition, by pointing out essential research areas such as optimizing culture conditions, increasing metabolite yields, and scaling up production, this work strengthens the significance of hairy root cultures in meeting the demand for high-value products while ensuring sustainable resource utilization. In particular, the integration of hairy root systems with advanced genomic tools such as transcriptomics and CRISPR technology holds immense potential for accelerating pathway-specific metabolic engineering, enhancing biosynthetic flux, and expanding their applications in sustainable agriculture and pharmaceutical innovation. This convergence is expected to drive substantial economic value by optimizing the production of high-value bioactive compounds, improving crop resilience, and facilitating precision medicine. Future work involving systems and synthetic biology will be instrumental in unlocking novel functions and ensuring broader deployment of hairy root cultures across industrial biotechnological platforms.

MeJA can help plants resist external stress, and waterlogging stress is the most serious stress for safflower. The mechanism by which MeJA (Methyl jasmonate) induction helps safflower resist waterlogging stress is unclear. Our results indicate that CtMYB63 responds to MeJA through the TGACG motif element, and MeJA induction can further increase the expression of CtMYB63. Under MeJA induction, CtMYB63 is expressed by regulating the transcriptional expression of CtDFR1, CtANS1 and CtANR1, thereby increasing the biomass and flavonoid content of safflower, but inhibiting plant elongation. Our waterlogging stress experiments further demonstrated that overexpression of CtMYB63 can enhance antioxidant enzyme activity to clear the accumulation of MDA (Malondialdehyde), H2O2, and O2-. We found that MeJA induction could further improve the waterlogging stress tolerance of overexpressed CtMYB63 and WT (wild-type) safflower. Still, the waterlogging tolerance of CtMYB63Δ was weakened due to the deletion of the TGACG motif element. Finally, we found through yeast one-hybrid (Y1H) and luciferase assays that CtMYB63 regulates the expression of downstream genes by binding to the promoters of downstream genes. However, CtJAZ9 inhibits the expression of downstream genes. In summary, our experiments show that CtMYB63 enhances the waterlogging tolerance of safflower through the JA signalling pathway, providing a new idea for improving safflower yield through molecular breeding.

Safflower (Carthamus tinctorius L.), a versatile medicinal and economic crop, harbors untapped genetic resources essential for stress resilience and metabolic regulation. The TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factors, exclusive to plants, are pivotal in orchestrating growth, development, and stress responses, yet their roles in safflower remain unexplored. Here, we report the comprehensive identification and characterization of 26 safflower TCP genes (CtTCPs), categorized into Class I (PROLIFERATING CELL FACTOR, PCF) and Class II (CINCINNATA and TEOSINTE BRANCHED1/CYCLOIDEA, CIN and CYC/TB1) subfamilies. Comparative phylogenetics, conserved motif, and gene structure analyses revealed a high degree of evolutionary conservation and functional divergence within the gene family. Promoter analyses uncovered light-, hormone-, and stress-responsive cis-elements, underscoring their regulatory potential. Functional insights from qRT-PCR analyses demonstrated dynamic CtTCP expression under abiotic stresses, including abscisic acid (ABA), Methyl Jasmonate (MeJA), Cold, and ultraviolet radiation b (UV-B) treatments. Notably, ABA stress triggered a significant increase in flavonoid accumulation, correlated with the upregulation of key flavonoid biosynthesis genes and select CtTCPs. These findings illuminate the complex regulatory networks underlying safflower’s abiotic stress responses and secondary metabolism, offering a molecular framework to enhance crop resilience and metabolic engineering for sustainable agriculture

Soil erosion is a major environmental challenge in arid and semi-arid regions of the world, and the relationship between climate and soil erosion has received considerable attention. Looking into long-term environmental variability would help quantify this relationship more accurately. New stratigraphical, physical-chemical, and micromorphological data from three representative loess-palaeosol sections-Milucun, Wufang, and Qishan-have been analysed to reconstruct the Holocene history of soil moisture and erosion in the southern Chinese Loess Plateau. The findings divide the Holocene into five stratigraphical units: two palaeosol (S01 and S02) and three loess layers (L0, Lx, and Lt), each reflecting a stage of monsoon patterns, sandstorm activity, temperature, and precipitation changes. Notably, during the formation of the early mid-Holocene palaeosol S02, average temperature was around 15.1 degrees C with annual precipitation of 808 mm, of which the East Asian summer monsoon contributed approximately 450 mm, surpassing non-monsoon sources of ca. 360 mm. The development of secondary argillans and dense woody root traces within S02, alongside shifts in clay mineral content, suggest elevated soil moisture between 8500 and 6000 years ago. This moisture likely sustained gravitational water, fostering a positive soil moisture balance and supporting lush forest vegetation. This study proposes that interglacials and interstadials experienced weaker soil erosion due to better vegetation cover, while glacials and stadials saw intensified erosion. A clear example is the Lx formation between 6000 and 5000 years ago, during which significant erosion led to the loss of this thin loess layer in much of the plateau.

Loess from the northern piedmont of the Dabie Mountains is exceptional, with classical loess to the north (i.e. the Chinese Loess Plateau), the Quaternary red soils to the south, and the Xiashu loess to the east. However, the mechanisms underlying the magnetic variation (enhancement and depletion) are not sufficiently understood. In this study, a multi-methodological approach (magnetic, geochemical, colorimetric, granulometric, and citratebicarbonate-dithionite (CBD)) was applied to improve our understanding of these issues. The following findings are highlighted. (1) The magnetic properties were remarkably different between the three light yellowish-brown silts and other units in the Hudian section. Specifically, minor fine ferrimagnetic minerals and more goethite were found in all three units. (2) The magnetic enhancement had a pedogenic origin, as suggested by the magnetic and CBD measurements. Specifically,-90 % of the magnetic mineralogy is affected by magnetic enhancement and-10 % is of detrital origin. (3) The fact that the three units underwent strong soil development was inconsistent with the magnetic records. Based on our records, combined with evidence from previous studies, our findings show that fine maghemite produced by strong pedogenic development were transformed into weakly magnetic goethite under humid environmental conditions. Dissolution of ferrimagnetic minerals can also contribute to magnetic depletion; however, the effect is limited. In summary, the magnetic enhancement of the loess from the northern piedmont of the Dabie Mountains was first induced by the development of pedogenesis, and then decreased by the conversion of fine pedogenic maghemite into weakly magnetic goethite and by dissolution due to wet pedogenic conditions. This provides critical regional evidence for studying the spatial evolution of the magnetic characteristics of loess in the north-south transect of China.

Domesticated safflower (Carthamus tinctorius L.) is a widely cultivated edible oil crop. However, despite its economic importance, the genetic basis underlying key traits such as oil content, resistance to biotic and abiotic stresses, and flowering time remains poorly understood. Here, we present the genome assembly for C. tinctorius variety Jihong01, which was obtained by integrating Oxford Nanopore Technologies (ONT) and BGI-SEQ500 sequencing results. The assembled genome was 1,061.1 Mb, and consisted of 32,379 protein-coding genes, 97.71% of which were functionally annotated. Safflower had a recent whole genome duplication (WGD) event in evolution history and diverged from sunflower approximately 37.3 million years ago. Through comparative genomic analysis at five seed development stages, we unveiled the pivotal roles of fatty acid desaturase 2 (FAD2) and fatty acid desaturase 6 (FAD6) in linoleic acid (LA) biosynthesis. Similarly, the differential gene expression analysis further reinforced the significance of these genes in regulating LA accumulation. Moreover, our investigation of seed fatty acid composition at different seed developmental stages unveiled the crucial roles of FAD2 and FAD6 in LA biosynthesis. These findings offer important insights into enhancing breeding programs for the improvement of quality traits and provide reference resource for further research on the natural properties of safflower.

Flavonol synthase gene (FLS) is a member of the 2-oxoglutarate-dependent dioxygenase (2-ODD) superfamily and plays an important role in plant flavonoids biosynthetic pathways. Safflower (Carthamus tinctorius L.), a key source of traditional Chinese medicine, is widely cultivated in China. Although the flavonoid biosynthetic pathway has been studied in several model species, it still remains to be explored in safflower. In this study, we aimed to elucidate the role of CtFLS1 gene in flavonoid biosynthesis and drought stress responses. The bioinformatics analysis on the CtFLS1 gene showed that it contains two FLS-specific motifs (PxxxIRxxxEQP and SxxTxLVP), suggesting its independent evolution. Further, the expression level of CtFLS1 in safflower showed a positive correlation with the accumulation level of total flavonoid content in four different flowering stages. In addition, CtFLS1-overexpression (OE) Arabidopsis plants significantly induced the expression levels of key genes involved in flavonol pathway. On the contrary, the expression of anthocyanin pathway-related genes and MYB transcription factors showed down-regulation. Furthermore, CtFLS1-OE plants promoted seed germination, as well as resistance to osmotic pressure and drought, and reduced sensitivity to ABA compared to mutant and wild-type plants. Moreover, CtFLS1 and CtANS1 were both subcellularly located at the cell membrane and nucleus; the yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assay showed that they interacted with each other at the cell membrane. Altogether, these findings suggest the positive role of CtFLS1 in alleviating drought stress by stimulating flavonols and anthocyanin accumulation in safflower.

Global cooling over the past 45 million years has been well established from deep sea isotopic records, and one explanation has been the cooling effect of uplift of the Tibetan Plateau. Other explanations for cooling are initiation of circum-Antarctic circulation, and carbon sequestration by newly evolved grasslands. The Lanzhou Basin is located at the intersection of the Tibetan Plateau, eastern monsoon region, and northwestern arid region of China, so well placed to evaluate Tibetan Plateau effects. This paper infers paleoclimatic changes from a long sequence of Cenozoic paleosols within the Xiliugou, Yehucheng and Xianshuihe Formations, in the Lanzhou Basin of Gansu. Eleven distinct kinds of paleosols (pedotypes) were recognized in the field from root traces, soil horizons and soil structures. These pedotypes were then intepreted as soils by R-mode factor analysis and molecular weathering ratios of major element geochemical composition. Supporting data from compactioncorrected depth to carbonate in the paleosols show that paleoclimate was persistently arid to semi-arid from the middle Eocene to the middle Miocene, but interrupted by transient climatic warm-wet events, which correlate with marine oxygen-isotopic events and large igneous province basaltic eruptions. At 42, 34, 22, 18, 17 and 16 Ma, spikes of mean annual temperature (MAT) and mean annual precipitation (MAP) are evident from the paleosols, at times also recognized in global marine isotopic and stomatal index carbon dioxide records. At 37, 33 and 23 Ma, low MAP and MAT estimated from paleosols of the Lanzhou Basin coincide with glacial advances, and marine oxygen isotopic spikes and low CO2. Paleosols of the Lanzhou Basin record global paleoclimate events during the middle Eocene to the middle Miocene, rather than variation in Tibetan Plateau uplift. The rain shadow from Tibetan Plateau maintained generally arid to subhumid eolian deposition in Gansu for the past 50 million years.

The APETALA2/ethylene-responsive element binding protein (AP2/ERF) is a highly conserved transcription factors family, involved in plant growth, development, and response to diverse stress conditions. Until recently, the AP2/ERF family has not been functionally characterized in safflower. In total, 187 AP2/ERF genes were identified from safflower genome. Phylogenetic analysis divided these CtAP2/ERFs into four distinct groups: DREB, ERFs, AP2s, and RAV genes. Furthermore, conserved protein motifs, gene structure, and cis-regulatory elements suggested important evolutionary insights into the potential role of these CtAP2/ERFs. Moreover, a comprehensive gene expression analysis conducted across various flowering stages demonstrated a consistent expression pattern of CtDREB52, which exhibited a significant correlation with alterations in the total flavonoid content. Importantly, CtDREB52 was found to be responsive to UV-B stress, and its overexpression in safflower not only promoted flavonoid accumulation but also induced an early flowering phenotype and up-regulated key genes of flavonoid pathway, while its silencing showed the opposite effect. Further, the interaction between CtDREB52 and CtDFR and CtMYB enzymes was confirmed through yeast two-hybrid and BiFC analysis. These findings provide important insights into CtDREB52-mediated regulation of flavonoid biosynthesis under UV-B stress by interacting with CtDFR and CtMYB in safflower.

Magnetotactic bacteria (MTB) combine passive alignment with the Earth magnetic field with a chemotactic response (magneto-chemotaxis) to reach their optimal living depth in chemically stratified environments. Current magneto-aerotaxis models fail to explain the occurrence of MTB far below the oxic-anoxic interface and the coexistence of MTB cells with opposite magnetotactic polarity at depths that are unrelated with the redox gradient. Here we propose a modified model of polar magnetotaxis which explains these observations, as well as the distinct concentration profiles and magnetotactic advantages of two types of MTB inhabiting a freshwater sediment: a group of unidentified cocci (MC), and a giant rod-shaped bacterium (MB) apparently identical to M. bavaricum (MB). This model assumed that magnetotactic polarity is set by a threshold mechanism in counter gradients of oxygen and a second group of repellents, with, in case of MB, includes H+ ions. MTB possessing this type of polar magnetotaxis can shuttle between two limit depths across the redox gradient (redox taxis), as previously postulated for M. bavaricum and other members of the Nitrospirota group. The magnetotaxis of MB and MC is predominantly dipolar whenever the presence of a magnetic field ensures a magnetotactic advantage. In addition, MB can overcome unfavorable magnetic field configurations through a temporal sensing mechanism. The availability of threshold and temporal sensing mechanisms of different substances can generate a rich variety of responses by different types of MTB, enabling them to exploit multiple ecological niches.

The article "Fas/FasL induces myocardial cell apoptosis in myocardial ischemia-reperfusion rat model", by X.-M. Liu, Z.-M. Yang, X.-K. Liu, published in Eur Rev Med Pharmacol Sci 2017; 21 (12): 2913-2918- PMID: 28682425 has been retracted by the Editor in Chief. Following some concerns raised on PubPeer (link: https://pubpeer.com/publications/29CE1A59A8180E414855FA3871BCAC), the Editor in Chief has started an investigation to assess the validity of the results as well as possible figure manipulation. The authors were informed about the journal's investigation but remained unresponsive and have not provided the manuscript's raw data. The journal's investigation revealed a figure overlap between panels 10 U/mL and 100 U/mL in Figure 1. Consequently, the Editor in Chief mistrusts the results presented and has decided to retract the article. This article has been retracted. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/12953.

Two hyperthermal events with different carbon cycle perturbations occurred across the Cretaceous-Palaeogene (K-Pg) boundary, i.e., the late Maastrichtian Warming Event (LMWE) and the early Danian Dan-C2 event. However, the roles played by Deccan volcanism and orbital forcing in these two hyperthermals are still debated. Here, we obtain a new terrestrial δ 13 C carb record in the Nanxiong Basin (southeastern China) and compare it with marine records. The results show that both the LMWE and Dan-C2 event can be well distinguished in the terrestrial record and that the Dan-C2 event is characterized by a typical hyperthermal event; however, the specificity of the context under which this event occurred has resulted in inconsistencies in the marine records. In addition, the δ 13 C excursion during the LMWE was more muted and prolonged than that during the Dan-C2 event, and the short-eccentricity cycle disappeared in the marine record during the LMWE, indicating that Deccan volcanism perturbed the carbon cycle during the LMWE, while the Dan-C2 event was less influenced by volcanic perturbation.

Safflower (Carthamus tinctorius L.) is a traditional Chinese medicinal herb renowned for its high flavonoid content and significant medicinal value. However, the dynamic changes in safflower petal flavonoid profiles across different flowering phases present a challenge in optimizing harvest timing and medicinal use. To enhance the utilization of safflower, this study conducted an integrated transcriptomic and metabolomic analysis of safflower petals at different flowering stages. Our findings revealed that certain flavonoids were more abundant during the fading stage, while others peaked during full bloom. Specifically, seven metabolites, including p-coumaric acid, naringenin chalcone, naringenin, dihydrokaempferol, apigenin, kaempferol, and quercetin, accumulated significantly during the fading stage. In contrast, dihydromyricetin and delphinidin levels were notably reduced. Furthermore, key genes in the flavonoid biosynthesis pathway, such as 4CL, DFR, and ANR, exhibited up-regulated expression with safflower’s flowering progression, whereas CHI, F3H, and FLS were down-regulated. Additionally, exposure to UV-B stress at full bloom led to an up-regulation of flavonoid content and altered the expression of key flavonoid biosynthetic genes over time. This study not only elucidates the regulatory mechanisms underlying flavonoid metabolism in safflower but also provides insights for maximizing its medicinal and industrial applications.

Magnetotactic bacteria (MTB) combine passive alignment with the Earth magnetic field with a chemotactic response (magneto-chemotaxis) to reach their optimal living depth in chemically stratified environments. Current magneto-aerotaxis models fail to explain the occurrence of MTB far below the oxic-anoxic interface and the coexistence of MTB cells with opposite magnetotactic polarity at depths that are unrelated with the redox gradient. Here we propose a modified model of polar magnetotaxis which explains these observations, as well as the distinct concentration profiles and magnetotactic advantages of two types of MTB inhabiting a freshwater sediment: Magnetobacterium bavaricum (MB) and a group unidentified, wild-type cocci (MC). This model assumed that magnetotactic polarity is set by a threshold mechanism in counter gradients of oxygen and a second group of repellents, with, in case of MB, includes H+ ions. Depending on the position of the two repellent thresholds in a vertical redox gradient, MTB possessing this type of polar magnetotaxis either accumulate around a preferred depth where the opposed stimuli set by the two repellents are equivalent, or shuttle between two limit depths across the redox gradient (redox taxis). We show that MB belongs to the latter category, as previously postulated for MB and other members of the Nitrospirae group. Microcosm experiments suggest that redox taxis might be assisted by a partial control of magnetotactic polarity by cell metabolism, which helps maintaining a consistent polarity bias during shuttling. Our model of polar magnetotaxis supports a large variety of magnetotactic behaviors, depending on the position of the two repellent thresholds in a redox gradient, enabling different types of MTB to occupy different ecological niches in the same environment.

AbstractTwo hyperthermal events with different carbon cycle perturbations occurred across the Cretaceous-Palaeogene boundary, i.e., the late Maastrichtian Warming Event and the Early Danian Dan-C2 event. However, the roles played by Deccan volcanism and orbital forcing in these two hyperthermal events are still debated. Here we obtain a terrestrial δ13Ccarb record in the Nanxiong Basin (southeastern China) and compare it with marine records. The results show that both hyperthermal events can be well distinguished and that the Dan-C2 event is characterized by a typical hyperthermal event. In addition, the δ13C excursion during the late Maastrichtian Warming Event was more muted and prolonged than that during the Dan-C2 event, and the short-eccentricity cycle disappeared in the marine record during the late Maastrichtian Warming Event, indicating that Deccan volcanism perturbed the carbon cycle during the late Maastrichtian Warming Event, while the Dan-C2 event was less influenced by volcanic perturbation.