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Understanding the process of signal communication between pollen and stigma is of significant importance for plant sexual reproduction. In the case of inter‐subgeneric hybridization in water lily, a pre‐fertilization hybridization barrier exists, the regulatory mechanism of which remains unclear. In this study, we conducted hormone and transcriptome analyses of unpollinated stigmas (Mock), self‐pollinated stigmas (SP), cross‐pollinated stigmas within the same subgenus (CP), and inter‐subgenus cross‐pollination stigmas (ISCP) in water lily to elucidate the formation mechanism of the inter‐subgeneric hybridization barrier. Our results indicated that the lack of abscisic acid (ABA) and brassinolide (BR) in ISCP stigmas are key factors contributing to the formation of the inter‐subgeneric hybridization barrier in water lily. Exogenous application of ABA and BR can help overcome the barrier between inter‐subgeneric water lily crosses. Through transcriptome analysis, we identified nine candidate genes involved in regulating the inter‐subgeneric hybridization barrier in water lily. In addition, we further demonstrated the importance of the NCED2‐mediated ABA synthesis pathway in the pollination process through AS‐ODN technology. Our study confirms that ABA and BR are critical for breaking the inter‐subgeneric hybridization barrier. The identification of the nine candidate genes provides important clues for further research on the hybridization recognition mechanism in water lily. [ABSTRACT FROM AUTHOR]

Tephra layers are common in lake sediments and although they have often been used as chronological controls, few studies have investigated the impacts of past tephra depositions on lake ecosystems (Tephropalaeoecology). For the first time we systematically assess how different types of tephra layers vary in their ecological impact on the same lacustrine system. We use a diatom-based tephropalaeoecological approach to infer the impacts of five tephra deposits on Lake Sihailongwan, a well-studied volcanic lake in Northeast China, over the past 30,000 years. The five tephra layers (including two micro-tephras) have varying thicknesses and were deposited in time periods with different climatic conditions. Changes in diatom communities and chrysophyte-cyst concentrations between pre- and post-tephra samples were used to infer changes in lake conditions and highlight the importance of lake background conditions in mediating the impact of tephra. While the two micro-tephra layers did not cause observable changes, the three thicker tephras induced pronounced changes in lake conditions and thus diatom communities. The two thick tephras deposited in more eutrophic and warmer lake conditions caused larger responses from diatoms. We argue that water-column phosphorus decreased due to reduced sediment–water-phosphorus loading as thick tephra layers formed an impermeable layer at the lake bottom. This is supported by a decrease in total diatom concentration and a decline in high phosphorus-requiring taxa such as Discostella stelligeroides and Stephanodiscus minutulus as well as modern limnological observations which showed that groundwater influxes from the lake bottom are the main source of nutrients to the lake. By contrast, the thick tephra deposited in more oligotrophic and colder lake conditions caused less conspicuous changes. When the lake was already low in phosphorus, diatoms did not respond to a further decline in phosphorus but rather responded to the minor increase in silica from the dissolution of tephra particles in the water column. This was inferred from the slight increases in overall diatom concentration and opportunistic taxa such as Pantocsekiella comensis f. minima. Diatom analysis of the post-tephra sediments above the three thick tephras showed that the aquatic ecosystem did not completely recover, indicating the long-lasting effects of these thick tephras and shifts to new lake-ecosystem equilibria. [ABSTRACT FROM AUTHOR]

Broccoli (Brassica oleracea var. italica) is an important B. oleracea cultivar, with high economic and agronomic value. However, comparative genome analyses are still needed to clarify variation among cultivars and phylogenetic relationships within the family Brassicaceae. Herein, the complete chloroplast (cp) genome of broccoli was generated by Illumina sequencing platform to provide basic information for genetic studies and to establish phylogenetic relationships within Brassicaceae. The whole genome was 153,364 bp, including two inverted repeat (IR) regions of 26,197 bp each, separated by a small single copy (SSC) region of 17,834 bp and a large single copy (LSC) region of 83,136 bp. The total GC content of the entire chloroplast genome accounts for 36%, while the GC content in each region of SSC,LSC, and IR accounts for 29.1%, 34.15% and 42.35%, respectively. The genome harbored 133 genes, including 88 protein-coding genes, 37 tRNAs, and 8 rRNAs, with 17 duplicates in IRs. The most abundant amino acid was leucine and the least abundant was cysteine. Codon usage analyses revealed a bias for A/T-ending codons. A total of 35 repeat sequences and 92 simple sequence repeats were detected, and the SC-IR boundary regions were variable between the seven cp genomes. A phylogenetic analysis suggested that broccoli is closely related to Brassica oleracea var. italica MH388764.1, Brassica oleracea var. italica MH388765.1, and Brassica oleracea NC_0441167.1. Our results are expected to be useful for further species identification, population genetics analyses, and biological research on broccoli. [ABSTRACT FROM AUTHOR]

Far‐travelled ash layers from explosive volcanic eruptions can provide invaluable marker horizons for dating and correlating regional to global sedimentary archives. Here, we present a new cryptotephra associated with the ~5.9 cal ka bp Towada‐Chuseri eruption (To‐Cu) in a peat sediment record from northeast China. This tephra exhibits a rhyolitic glass composition that can be distinguished from other widespread tephra layers around the region of Japan and northeast China. Our findings extend the known range of this ash significantly, making it now traceable about 1200 km from its source, Towada volcano, Japan. Notably, this tephra provides an important isochron for synchronising palaeoenvironmental studies during the mid‐Holocene period from the western Pacific, central Japan, Japan Sea and northeast China. [ABSTRACT FROM AUTHOR]

North Pacific Ocean sediments are important archives of geomagnetic field and paleoenvironmental evolutions, yet late Quaternary sedimentary sequences in the North Pacific Ocean are less explored because of generally low sedimentation rates and the challenge of dating sediments deposited below the calcite compensation depth. Core NP02 sediments from the North Pacific Ocean contain three visible tephra layers, which are identified as the To‐Of, Spfa‐1, and Kt‐3 tephra, respectively. An age model for core NP02 is established based on tephra correlation and one radiocarbon date, which gives a mean sedimentation rate of ∼11.6 cm/kyr. Magnetic analyses suggest the dominance of two remanence carriers; detrital vortex state and biogenic single domain magnetite. Variable depth offsets between the relative paleointensity (RPI) signals carried by the two remanence carriers adds a negligible age error (<0.5 kyr) to the core NP02 RPI record. Pronounced RPI amplitude variations are observed, and the Rockall and Laschamp excursions are identified in the core NP02 RPI record based on the age model. The fidelity of the core NP02 RPI record is further verified by comparison with other RPI stacks and records, and we demonstrate that the RPI variations can assist in chronology refinement. Plain Language Summary: The North Pacific Ocean is too deep to preserve materials effectively for the oxygen isotope chronology, and sediments deposit slowly in this region. Therefore, dating is a big problem for late Quaternary sedimentary cores. In this study, core NP02 sediments from the North Pacific Ocean are studied. The To‐Of, Spfa‐1, and Kt‐3 tephra layers are identified in core NP02 sediments based on the geochemical features. An age model for this core is reconstructed with the aid of tephra ages and one radiocarbon date. Magnetic analyses suggest that both small biogenic and relatively large detrital magnetite record geomagnetic information, and the two groups of magnetite deposit at about the same time. Based on the age model, core NP02 RPI record preserves the Rockall and Laschamp excursions, and the RPI pattern is consistent with other RPI stacks and records, which verifies core NP02 RPI fidelity. Therefore, we demonstrate that RPI variations is a promising dating tool for North Pacific Ocean sediments. Key Points: We use an age model based on tephra correlation and one radiocarbon date to assess the fidelity of relative paleointensity variationsDetrital vortex state and biogenic single domain magnetite are the dominant remanence carriers, and they introduced <0.5 kyr age errorAssessment of component‐specific magnetic properties should be considered to ensure the reliability of relative paleointensity variations [ABSTRACT FROM AUTHOR]

Volcanic ash has been widely used as unique independent marker horizons for dating and synchronizing paleoenvironments and archeological records. Here, we report a series of key widespread late Pleistocene to Holocene tephras horizons from a lake sequence in southern China that have significant potential for dating and synchronizing paleoenvironmental records from East Asia. Translatitudinal paleoclimatological, paleoenvironmental, and archeological correlations from the tropical Philippines, mainland China, and midlatitude Japan are achievable through these extensively distributed tephras, including synthetic studies of the Younger Dryas and mid‐Holocene climate events. Additionally, we establish refined ages for four pre‐1991 Pinatubo eruptions and date three late Pleistocene Luzon eruptions based on the lake sequence age model, which will facilitate future studies of tropical volcanic eruptions' forcing of climate change. Our results highlight the volcanic hazards around densely populated East Asia, and bring solutions to resolving dating uncertainty in the synchronization of rapid climate events across the region. Plain Language Summary: Tephra layers have been hailed as valuable independent age‐equivalent marker layers for precisely correlating archives of past environmental change. Japan and south‐east Asia have the most active land‐based volcanoes on Earth, and ash from their eruptions can be traced as far as the polar ice cores. However, the volcanic histories and products from the regions are poorly constrained, limiting the ability to recognize the eruptions' wider climate and societal impacts, and to use far‐traveled ash as dating horizons. In this study, we investigated cryptotephra (volcanic ash particles that are invisible to the naked eye) in a lake sequence from southern China. Cryptotephra from the Philippines, Japan, and South Korea was identified in the lake sediment. The discovery of these tephras in southern China significantly extends the volcanic ash distributions of several known late Pleistocene to Holocene eruptions from this region, and indicates that these prehistoric eruptions may have frequently impacted on some of the most densely populated parts of East Asia. These extensively distributed tephras will provide excellent dating horizons for future climate studies in this region. Key Points: We present the first high‐resolution late Pleistocene to Holocene cryptotephra sequence in mainland ChinaA series of key widespread late Pleistocene to Holocene tephra isochrons around East Asia is establishedWe refine the dating of late Pleistocene to Holocene eruptions from Pinatubo and a volcano from southwest Luzon [ABSTRACT FROM AUTHOR]

Background: Polycystic Ovary Syndrome (PCOS) is a major cause of anovulatory infertility. Some studies showed that miRNAs were used as diagnostic/prognostic biomarkers for various diseases.Objective: To identify candidate miRNAs in Granulosa Cells (GCs) of PCOS and evaluate their potential values for PCOS diagnosis.Methods: We screened differentially expressed miRNAs in GCs between PCOS and controls by the microarray data from the GEO database. GCs were collected from 21 controls and 24 PCOS. The candidate miRNAs were verified by qRT-PCR. The correlation was investigated between candidate miRNAs and clinical characteristics in participants. Diagnostic value of candidate miRNAs was analyzed by receiver operating characteristic (ROC) curve.Results: Seven miRNAs were differentially expressed in PCOS compared with controls. Furthermore, the validation results demonstrated that hsa-miR-3188 and hsa-miR-3135b showed higher levels in GCs with PCOS patients (p< 0.05). In addition, the expressions of hsa-miR-3188 and hsa-miR-3135b were negative correlated with FSH and hsa-miR-3188 was positive correlated with BMI (p< 0.05). ROC analysis indicated that hsa-miR-3188 and hsa-miR-3135b could differentiate PCOS from controls, and the hsa-miR-3188/3135b improved the predictive accuracy for PCOS.Conclusions: The expressions of hsa-miR-3188 and hsa-miR-3135b in human GCs were significantly associated with PCOS. Moreover, the hsa-miR-3188/3135b has certain diagnostic value for distinguishing PCOS. [ABSTRACT FROM AUTHOR]

Abstract: Prehistoric Holocene eruptions of Changbaishan volcano in Northeast China are poorly dated, with the exception of the 946 CE Millennium eruption. Poorly refined age estimates for the earlier eruptions present problems for the reconstruction of the eruptive history of the volcano. The Qixiangzhan eruption (QE) is a major controversial event in terms of its eruptive timing (ranging from ~88 to ~4 kyr) and style (effusive or explosive). As a result of the imprecise age estimates for the eruption, a geomagnetic field excursion recorded within the QE comendite has been variably correlated with a number of different excursion events observed elsewhere. In this study, a visible early Holocene tephra was identified in Yuanchi Lake, ~30 km east of the Changbaishan volcanic vent, and was dated to 8831‐8100 cal yr BP using Bayesian age modelling. Glass shard compositions enable the correlation of this tephra with the poorly dated QE, as well as with a tephra (SG14‐1058) recorded in Lake Suigetsu, in central Japan. These correlations confirm that the QE was explosive and that the ash from the QE can serve as an important early Holocene marker bed across East Asia. In addition, we propose an age of ~8100 cal yr BP for the QE based on the precise date of the Suigetsu SG14‐1058 tephra. Our results also confirm that the geomagnetic field excursion recorded in the Qixiangzhan comendite dates to ~8100 cal yr BP. [ABSTRACT FROM AUTHOR]

Volcanic glass compositions and tephra layer age are critical for anchoring their sources and correlating among different sites; however, such work may be imprecise when the tephra has varied compositions. The ash from Changbaishan Millennium eruption (940s AD), a widely distributed tephra layer, has been detected in the far-east areas of Russia, the Korean Peninsula, Japan, and in Greenland ice cores. There are some debates on the presence of this tephra from sedimentary archives to the west of Changbaishan volcano, such as lake and peat sediments in the Longgang volcanic field. In this paper, major element compositions for clinopyroxene and Fe-Ti oxides were performed on proximal tephra from Changbaishan and the Millennium eruption ash record in Lake Sihailongwan. Clinopyroxene and Fe-Ti oxides microlites from Sihailongwan show augite- ferroaugite and titanmagnetite compositions, similar to those from dark pumice in Changbaishan proximal tephra, but different from the light grey pumice, which has ferrohedenbergite and ilmenite microlite compositions. This result implies that the tephra recorded in Sihailongwan was mainly from the trachytic eruptive phase of the Millennium eruption, and the rhyolitic eruptive phase made a relatively small contribution to this area. Analyzing clinopyroxene and Fe-Ti oxides microlites is a new method for correlating tephra layers from Changbaishan Millennium eruption. [ABSTRACT FROM AUTHOR]

Large explosive volcanic eruptions generate extensive regional tephra deposits that provide favorable conditions for identifying the source of volcanoes, comparing the sedimentary strata of a region and determining their ages. The tephra layer, referred to as B-Tm, generated by the Millennium eruption of Changbaishan volcano, is widely distributed in Northeast China, Japan, D.P.R. Korea, and the nearby coastal area of Russia. It forms part of the widespread northeast Asian strata and is significant for establishing an isochronal stratigraphic framework. However, research on the temporal characterization and stratigraphic correlation of associated strata using this tephra layer is mainly concentrated in and near Japan. In northeastern China, this tephra layer is seldom seen and its application in stratigraphic correlations is even rarer. More importantly, the determination of accurate ages for both distal and proximal tephras has been debated, leading to controversy in discussions of its environmental impacts. Stratigraphic records from both distal and proximal Changbaishan ash show that this eruption generally occurred between 1,012 and 1,004 cal yr BP. Geochemical comparison between Changbaishan ash and the Quaternary widespread ash around Japan illustrates that Changbaishan ash is a continuous composition from rhyolitic to trachytic and its ratio of FeO to CaO is usually greater than 4, which can be used as a distinguishing identifier among worldwide contemporary eruptions. [ABSTRACT FROM AUTHOR]