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Volcanic acidification creates extreme soil conditions, where rhizotoxicity from extremely low pH (2–3) and high Al3+ strongly inhibit plant growth. C. angustisquama is a dominant extremophyte in highly acidic solfatara fields, where no other vascular plants can survive. Here we investigated the key abiotic stressor determining survival of this extremophyte.Soil analyses and topographic surveys were conducted to examine the effects of low pH and Al3+, two major abiotic stressors in acidic soils, on the occurrence of C. angustisquama in solfatara fields. Hydroponic culture experiments were also performed to test its growth responses to these stressors.In field surveys, the spatial distribution of soil pH was consistent with vegetation zonation within a solfatara field. In contrast, soil exchangeable Al content was overall low due to strong eluviation. Statistical analysis also supported the significant role of soil pH in determining the distribution of C. angustisquama in a solfatara field. Furthermore, hydroponic culture experiments revealed a higher tolerance of C. angustisquama to low pH than a sister species, especially in the range pH 2–3, corresponding to the pH values of the actual habitats of C. angustisquama. Conversely, no significant interspecific difference was detected in Al3+ tolerance, indicating that both species had high Al3+ tolerance.This study suggests that low pH is a critical abiotic stressor leading to formation of the extremophyte in highly acidic solfatara fields. In contrast, C. angustisquama displayed high tolerance to Al3+ toxicity, probably acquired prior to speciation. [ABSTRACT FROM AUTHOR]

Wild radish (Raphanus sativus L. var. hortensis f. raphanistroides Makino) is widely distributed in East Asia; however, its genetic diversity and population structure remain poorly understood. In our study, DNA sequence and microsatellite loci were used to analyze wild radish populations across the whole East Asia. Population genetic diversity analysis showed that the East Asian wild radish populations generally had high genetic diversity (average HO=0.448), distinct population structure, and a positive correlation between genetic distance and geographic distance. AMOVA analysis suggested the genetic diversity among individuals in populations by far exceeded the diversity among populations/groups. The outcrossing breeding system, long geographic distance between populations and gene flow from cultivated radish populations may explain the high level of genetic diversity within wild populations. Bayesian cluster analysis identified four genetic clusters in the East Asian wild radish populations, observed by DNA sequencing analysis. The possible factors would be various aspects, such as oceanic barrier, climate fluctuations, and pollinators' characteristics. This study provides a reference for the utilization of wild radish germplasm resources and the improvement of radish varieties in East Asia. [ABSTRACT FROM AUTHOR]

Abstract Background Understanding demographic histories, such as divergence time, patterns of gene flow, and population size changes, in ecologically diverging lineages provide implications for the process and maintenance of population differentiation by ecological adaptation. This study addressed the demographic histories in two independently derived lineages of flood-resistant riparian plants and their non-riparian relatives [Ainsliaea linearis (riparian) and A. apiculata (non-riparian); A. oblonga (riparian) and A. macroclinidioides (non-riparian); Asteraceae] using an isolation-with-migration (IM) model based on variation at 10 nuclear DNA loci. Results The highest posterior probabilities of the divergence time parameters were estimated to be ca. 25,000 years ago for A. linearis and A. apiculata and ca. 9000 years ago for A. oblonga and A. macroclinidioides, although the confidence intervals of the parameters had broad ranges. The likelihood ratio tests detected evidence of historical gene flow between both riparian/non-riparian species pairs. The riparian populations showed lower levels of genetic diversity and a significant reduction in effective population sizes compared to the non-riparian populations and their ancestral populations. Conclusions This study showed the recent origins of flood-resistant riparian plants, which are remarkable examples of plant ecological adaptation. The recent divergence and genetic signatures of historical gene flow among riparian/non-riparian species implied that they underwent morphological and ecological differentiation within short evolutionary timescales and have maintained their species boundaries in the face of gene flow. Comparative analyses of adaptive divergence in two sets of riparian/non-riparian lineages suggested that strong natural selection by flooding had frequently reduced the genetic diversity and size of riparian populations through genetic drift, possibly leading to fixation of adaptive traits in riparian populations. The two sets of riparian/non-riparian lineages showed contrasting patterns of gene flow and genetic differentiation, implying that each lineage showed different degrees of reproductive isolation and that they had experienced unique evolutionary and demographic histories in the process of adaptive divergence.

The Ogasawara Islands, representing an oceanic island ecosystem in Japan, have a notably high rate of endemic species akin to other oceanic islands globally. Pittosporum parvifolium is a critically endangered shrub with only four remaining individuals in its natural habitat on the Ogasawara Islands. Current conservation efforts encompass both in situ and ex situ approaches for P. parvifolium . However, these efforts face challenges stemming from the lack of critical conservation information. Therefore, we explored P. parvifolium 's genetic diversity and implications for conservation. We utilized simple sequence repeat markers to scrutinize genetic diversity within both in situ and ex situ populations, revealing notably rich diversity among both. The in situ genetic diversity was significantly high despite the few extant individuals. In addition, many of the ex situ peculiar genotypes were absent in individuals conserved in situ. This investigation also provides insights into the reproductive strategies and combinations of selfing and outcrossing. The results of the present study recommend conservation to maximize genetic diversity in P. parvifolium by promoting cross-pollination among in situ individuals and by introducing individuals with unique genotypes into ex situ stocks., Competing Interests: The authors declare no conflicts of interest., (© 2024 The Author(s). Ecology and Evolution published by John Wiley & Sons Ltd.)

Extreme environments and plants thriving in them, known as extremophytes, offer promising platforms for studying the diverse adaptive mechanisms that have evolved in plants. However, research on adaptation to extreme environments is still limited to those environments where model species or their relative can survive. Fumarole fields, an extreme environment often overlooked, are characterized by multi-hazardous abiotic stressors, including atmospheric contamination (high concentration of H2S, SO2, and CO2), high soil temperature (~60℃), and strong soil acidification (pH=2-3). These conditions make fumarole fields a rich source for studying stress tolerance mechanisms in plants. In this review, we highlight the recent ecological, physiological, and genomic advances involved in fumarole field adaptation, and discuss the forward avenues. The studies outlined in this paper demonstrate that the extreme levels of abiotic stressors found in fumarole fields make them unparalleled field laboratories for studying the unknown stress tolerance mechanisms, warranting further genomic assessments. Some studies succeeded in identifying genes associated with fumarole field adaptation and shedding light on evolutionary implications; however, they have also encountered challenges such as limited genome resources and high genetic differentiation from related species and/or neighboring populations. To overcome such difficulties, we propose integrating ecophysiological and genomic approaches, drawing from the recent studies in other extreme environments. We expect that further studies in the fumarole fields will contribute to broadening our general knowledge of the limits of life., (© The Author(s) 2024. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site–for further information please contact journals.permissions@oup.com.)

Key Clinical Message: Genetic variants associated with hereditary TAAD may contribute to nonsyndromic TAAD. We present the case of a 72-year-old man with nonsyndromic TAAD undergoing prophylactic surgery after a gene panel test revealed a pathogenic variant in TGFBR1 , but the indication for genetic testing in such elderly-onset cases still warrants further discussion., Abstract: Hereditary thoracic aortic aneurysm and dissection (TAAD) is a serious clinical condition resulting in a fatal outcome. Recently, variants in causative genes for syndromic hereditary TAAD, such as Marfan syndrome and Loeys-Dietz syndrome (LDS), have been reported to predispose to the development of nonsyndromic TAAD; however, genetic testing for patients with elderly-onset nonsyndromic TAAD warrants further discussion. We present a 72-year-old nonsyndromic Japanese man with moderate-sized aortic annulus ectasia (AAE) with moderate aortic regurgitation and ascending to distal arch aortic dilatation (maximum diameter: 46 mm). He had been treated for hypertension and dyslipidemia for 7 years, and his eldest son had AAE at 33 years old and type A aortic dissection at 43 years old. Surgical repair was considered a treatment option because the patient potentially had a nonsyndromic hereditary aortic disease, and genetic panel testing for TAAD identified a pathogenic missense variant in TGFBR1 (c.934G > A, p.[Gly312Ser]), previously reported in patients with LDS type 1. He was diagnosed with nonsyndromic TGFBR1 -related aortopathy and underwent prophylactic surgery using a modified Bentall operation and total arch replacement with open stent graft implantation. Genetic testing was useful in guiding the treatment strategy, but further analysis is warranted to establish the clinical value in the treatment plan for patients with elderly-onset nonsyndromic TAAD., Competing Interests: The authors have no conflict of interest to declare., (© 2024 The Author(s). Clinical Case Reports published by John Wiley & Sons Ltd.)

Premise: Light is essential for plants, and local populations exhibit adaptive photosynthetic traits depending on their habitats. Although plastic responses in morphological and/or physiological characteristics to different light intensities are well known, adaptive divergence with genetic variation remains to be explored. This study focused on Saxifraga fortunei (Saxifragaceae) growing in sun-exposed and shaded habitats., Methods: We measured the leaf anatomical structure and photosynthetic rate of plants grown in their natural habitats and in a common greenhouse (high- and low-intensity light experimental sites). To assess differences in ecophysiological tolerance to high-intensity light between the sun and shade types, we evaluated the level of photoinhibition of photosystem II and the leaf mortality rate under high-intensity light conditions. In addition, population genetic analysis was conducted to investigate phylogenetic origins., Results: Clear phenotypic differences were found between the sun and shade types despite their recent phylogenetic origin. The leaf anatomical structure and photosynthetic rate showed plastic changes in response to growing conditions. Moreover, the sun type had a well-developed palisade parenchyma and a higher photosynthetic rate, which were genetically fixed, and a lower level of photoinhibition under high-intensity light., Conclusions: Our findings demonstrate that light intensity is a selective pressure that can rapidly promote phenotypic divergence between the sun and shade types. While phenotypic changes in multiple photosynthetic traits were plastic, genetic divergence in specific traits related to adaptation to high-intensity light would be fundamental for ecotypic divergence to different light regimes., (© 2024 Botanical Society of America.)

Corylopsis Siebold & Zucc. (Hamamelidaceae) is widely used as a horticultural plant and comprises approximately 25 species in East Asia. Molecular research is essential to distinguish Corylopsis species, which are morphologically similar. Molecular research has been conducted using a small number of genes but not in Corylopsis . Plastid genomes of Corylopsis species ( Corylopsis gotoana, Corylopsis pauciflora , and Corylopsis sinensis ) were sequenced using next-generation sequencing techniques. Repeats and nucleotide diversity that could be used as DNA markers were also investigated. A phylogenetic investigation was carried out using 79 protein-coding genes to infer the evolutionary relationships within the genus Corylopsis . By including new plastomes, the overall plastid genome structure of Corylopsis was similar. Simple sequence repeats of 73-106 SSRs were identified in the protein-coding genes of the plastid genomes, and 33-40 long repeat sequences were identified in the plastomes. The Pi value of the rpl33_rps18 region, an intergenic spacer, was the highest. Phylogenetic analysis demonstrated that Corylopsis is a monophyletic group and Loropetalum is closely related to Corylopsis . C. pauciflora, C. gotoana , and C. spicata formed a clade distributed in Japan, whereas C. sinensis , C. glandulifera , and C. velutina formed a clade that was distributed in China.

Premise: Snow is an important environmental factor affecting plant distribution. Past changes in snowfall regimes may have controlled the demographies of snow-dependent plants. However, our knowledge of changes in the distribution and demographies of such plants is limited because of the lack of fossil records., Methods: Population genetic and landscape genetic analyses were used to investigate the response of population dynamics of Arnica mallotopus (Asteraceae)-a plant confined to heavy-snow areas of Japan-to changes in snowfall regimes from the Last Glacial Period to the Holocene., Results: The population genetic analysis suggested that the four geographic lineages diverged during the Last Glacial Period. The interaction between reduced snowfall and lower temperatures during this period likely triggered population isolation in separate refugia. Subpopulation differentiation in the northern group was lower than in the southern group. Our ecological niche model predicted that the current distribution was patchy in the southern region; that is, the populations were isolated by topologically flat and climatically unsuitable lowlands. The landscape genetic analysis suggested that areas with little snowfall acted as barriers to the Holocene expansion of species distribution and continued limiting gene flow between local populations., Conclusions: These findings indicate that postglacial population responses vary among regions and are controlled by environmental and geographic factors. Thus, changes in snowfall regime played a major role in shaping the distribution and genetic structure of the snow-dependent plant., (© 2024 Botanical Society of America.)

The Ryukyu Islands of Japan are a biodiversity hotspot due to geographical and historical factors. Tricyrtis formosana is a perennial herbaceous plant that commonly found in Taiwan. But only a few populations have been identified in a limited habitat on Iriomote Island, while populations of unknown origin occur near human settlements in an area on the main island of Okinawa. To better understand these populations of the phylogenetic uniqueness and intrinsic vulnerability, we conducted comparative analyses including (1) phylogeny and population structure with MIG-seq data, (2) photosynthesis-related traits of plants grown under common conditions and (3) transcriptome analysis to detect deleterious variations. Results revealed that T. formosana was split into two clades by the congeners and that Iriomote and Okinawa populations independently derived from ancestral Taiwanese populations in each clade. Photosynthetic efficiency was lowest in the Iriomote population, followed by Okinawa and Taiwan. Transcriptome analysis showed that the Iriomote population accumulated more deleterious variations, suggesting intrinsic vulnerability. These results indicate that each T. formosana population in Japan is phylogenetically unique and has been independently dispersed from Taiwan, and that the Iriomote population presents a high conservation difficulty with a unique photosynthesis-related characteristic and a larger amount of deleterious variations., (© 2024. The Author(s).)

Volcanic acidification creates extreme soil conditions, where rhizotoxicity from extremely low pH (2-3) and high Al 3+ strongly inhibit plant growth. C. angustisquama is a dominant extremophyte in highly acidic solfatara fields, where no other vascular plants can survive. Here we investigated the key abiotic stressor determining survival of this extremophyte. Soil analyses and topographic surveys were conducted to examine the effects of low pH and Al 3+ , two major abiotic stressors in acidic soils, on the occurrence of C. angustisquama in solfatara fields. Hydroponic culture experiments were also performed to test its growth responses to these stressors. In field surveys, the spatial distribution of soil pH was consistent with vegetation zonation within a solfatara field. In contrast, soil exchangeable Al content was overall low due to strong eluviation. Statistical analysis also supported the significant role of soil pH in determining the distribution of C. angustisquama in a solfatara field. Furthermore, hydroponic culture experiments revealed a higher tolerance of C. angustisquama to low pH than a sister species, especially in the range pH 2-3, corresponding to the pH values of the actual habitats of C. angustisquama. Conversely, no significant interspecific difference was detected in Al 3+ tolerance, indicating that both species had high Al 3+ tolerance. This study suggests that low pH is a critical abiotic stressor leading to formation of the extremophyte in highly acidic solfatara fields. In contrast, C. angustisquama displayed high tolerance to Al 3+ toxicity, probably acquired prior to speciation., (© 2023 German Society for Plant Sciences, Royal Botanical Society of the Netherlands.)

Some patients admitted to intensive care units (ICU) would develop delirium, which is associated with poor prognosis. The purpose of this retrospective study was to identify factors associated with ICU delirium in patients with acute myocardial infarction (AMI). We included 753 AMI and divided those into the ICU-delirium group (n = 110) and the non-ICU-delirium group (n = 643) according to the presence of ICU delirium. The ICU delirium was evaluated by confusion assessment method for the intensive care unit. Patient characteristics and clinical outcomes were compared between the 2 groups, and factors associated with ICU delirium were sought by multivariate analysis. The prevalence of female sex was significantly higher in the ICU-delirium group (43.6%) than in the non-ICU-delirium group (20.2%) (p < 0.001). The incidence of in-hospital death was significantly higher in the ICU-delirium group (17.3%) than in the non-ICU-delirium group (0.5%) (p < 0.001). The multivariate logistic regression analysis revealed that age [every 10 years increase: odds ratio (OR) 1.439, 95% confidence interval (CI) 1.127-1.837, p = 0.004], female sex (OR 2.237, 95%CI 1.300-3.849, p = 0.004), triple vessel disease (OR 2.317, 95%CI 1.365-3.932, p = 0.002), body mass index < 18.5 kg/m 2 (OR 2.910, 95%CI 1.410-6.008, p = 0.004), use of mechanical support (OR 2.812, 95%CI 1.500-5.270, p = 0.001), respiratory failure (OR 5.342, 95%CI 3.080-9.265, p < 0.001), and use of continuous renal replacement therapy (OR 5.901, 95%CI 2.520-13.819, p < 0.001) were significantly associated with ICU delirium. In conclusion, ICU delirium was associated with in-hospital death. Older age, female sex, triple vessel disease, leanness, use of mechanical support, respiratory failure, and continuous renal replacement therapy were significantly associated with the occurrence of ICU delirium., (© 2022. Springer Japan KK, part of Springer Nature.)

Interspecific hybridization is a critical issue in conservation biology because it may drive small populations to extinction through direct or indirect processes. In this study, to develop a conservation strategy for an endangered rear-edge population of Carex podogyna in Ashiu, Kyoto, Japan, we performed a molecular genetic analysis of the wild population and an ex-situ population established from wild seeds. Microsatellite genotypic data revealed a complete loss of genetic diversity in the wild population, suggesting that it has long been prone to genetic drift due to isolation as a small population. In contrast, microsatellite analysis of 13 ex-situ individuals detected multiple alleles that are not harbored in the wild C. podogyna population. Sequence analysis revealed that these individuals are likely natural hybrids between C. podogyna and a co-occurring species, C. curvicollis, although established hybrids have never been found in the natural habitat. Based on our observation of variegated leaves in hybrid individuals, we propose that hybrids have been excluded by natural selection and/or interspecific competition caused by insufficient productivity of photosynthesis, although other genetic and ecological factors may also be influential. Overall, this study indicates that natural mechanisms selectively removing the hybrids have maintained the genetic purity of this rear-edge population of C. podogyna, and also emphasizes the importance of genetic assessment in ex-situ conservation programs.