Immunomodulatory effects of flazin from Crassostrea sikamea on splenic lymphocytes of Sprague-Dawley rats.

Crassostrea sikamea (C.sikamea) is an important edible and medicinal seafood in China. In the present study, a compound named flazin was separated and identified from the ethyl acetate extract of C.sikamea (EAECs) for the first time. In addition, the 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetra zolium (MTS) assay revealed that EAECs and flazin inhibited the transformation of splenic lymphocytes in vitro. Moreover, flazin (20 µg·mL-1) altered the populations of splenic lymphocyte subtypes. Real-time quantitative PCR (RT-qPCR) analysis and enzyme-linked immunosorbent assay (ELISA) showed that flazin suppressed the mRNA expression and secretion of TNF-α and IL-2, and reversed Concanavalin A (ConA)-induced mRNA up-regulation and protein secretion of TNF-α and IL-2. Western blot results showed that flazin reversed ConA-induced increases in p-ERK1/2 and p-p38 in splenocytes. In conclusion, flazin exhibits effective immunomodulatory function and may be useful for treating immune-related disorders, which indicates the application potential of C.sikamea as a functional food or immunomodulator.

Morphological, Physiological, and Molecular Responses of Sweetly Fragrant Luculia gratissima During the Floral Transition Stage Induced by Short-Day Photoperiod.

Photoperiod-regulated floral transition is vital to the flowering plant. Luculia gratissima "Xiangfei" is a flowering ornamental plant with high development potential economically and is a short-day woody perennial. However, the genetic regulation of short-day-induced floral transition in L. gratissima is unclear. To systematically research the responses of L. gratissima during this process, dynamic changes in morphology, physiology, and transcript levels were observed and identified in different developmental stages of long-day- and short-day-treated L. gratissima plants. We found that floral transition in L. gratissima occurred 10 d after short-day induction, but flower bud differentiation did not occur at any stage under long-day conditions. A total of 1,226 differentially expressed genes were identified, of which 146 genes were associated with flowering pathways of sugar, phytohormones, photoperiod, ambient temperature, and aging signals, as well as floral integrator and meristem identity genes. The trehalose-6-phosphate signal positively modulated floral transition by interacting with SQUAMOSA PROMOTER-BINDING-LIKE PROTEIN 4 (SPL4) in the aging pathway. Endogenous gibberellin, abscisic acid, cytokinin, and jasmonic acid promoted floral transition, whereas strigolactone inhibited it. In the photoperiod pathway, FD, CONSTANS-LIKE 12, and nuclear factors Y positively controlled floral transition, whereas PSEUDO-RESPONSE REGULATOR 7, FLAVIN-BINDING KELCH REPEAT F-BOX PROTEIN 1, and LUX negatively regulated it. SPL4 and pEARLI1 positively affected floral transition. Suppressor of Overexpression of Constans 1 and AGAMOUSLIKE24 integrated multiple flowering signals to modulate the expression of FRUITFULL/AGL8, AP1, LEAFY, SEPALLATAs, SHORT VEGETATIVE PHASE, and TERMINAL FLOWER 1, thereby regulating floral transition. Finally, we propose a regulatory network model for short-day-induced floral transition in L. gratissima. This study improves our understanding of flowering time regulation in L. gratissima and provides knowledge for its production and commercialization.

Beneficial Effect of Alkaloids From Sophora alopecuroides L. on CUMS-Induced Depression Model Mice via Modulating Gut Microbiota.

It was recently shown that the gut microbiota of both depression patients and depression model animals is significantly altered, suggesting that gut microbes are closely related to depression. Here, we investigated the effects of Sophora alopecuroides L.-derived alkaloids on the gut microbiota of mice with depression-like behaviors. We first established a mouse model of depression via chronic unpredictable mild stress (CUMS) and detected changes in depression-like behaviors and depression-related indicators. Simultaneously, 16S rRNA sequencing was performed to investigate gut microbiota changes. Sophora alopecuroides L.-derived alkaloids improved depression-like behaviors and depression-related indicators in mice. The alkaloids decreased the gut microbiota diversity of CUMS mice and depleted intestinal differentially abundant "harmful" microbiota genera. Spearman analysis showed that there is a certain correlation between the differential microbiota (Lactobacillus, Helicobacter, Oscillospira, Odoribacter, Mucispirillum, Ruminococcus), depression-like behaviors, and depression-related indicators. Combined with the predictive analysis of gut microbiota function, these results indicate that alkaloids improve depression in mice through modulating gut microbiota.

Development and validation of machine learning prediction model based on computed tomography angiography-derived hemodynamics for rupture status of intracranial aneurysms: a Chinese multicenter study.

OBJECTIVES: To build models based on conventional logistic regression (LR) and machine learning (ML) algorithms combining clinical, morphological, and hemodynamic information to predict individual rupture status of unruptured intracranial aneurysms (UIAs), afterwards tested in internal and external validation datasets. METHODS: Patients with intracranial aneurysms diagnosed by computed tomography angiography and confirmed by invasive cerebral angiograph or clipping surgery were included. The prediction models were developed based on clinical, aneurysm morphological, and hemodynamic parameters by conventional LR and ML methods. RESULTS: The training, internal validation, and external validation cohorts were composed of 807 patients, 200 patients, and 108 patients, respectively. The area under curves (AUCs) of conventional LR models 1 (clinical), 2 (clinical and aneurysm morphological), and 3 (clinical, aneurysm morphological and hemodynamic characteristics) were 0.608, 0.765, and 0.886, respectively (all p < 0.05). The AUCs of ML models using random forest (RF), multilayer perceptron (MLP), and support vector machine (SVM) were 0.871, 0.851, and 0.863, respectively. There were no difference among AUCs of conventional LR, RF, and SVM (all p > 0.05/6), while the AUC of MLP was lower than that of conventional LR (p = 0.0055). CONCLUSION: Hemodynamic parameters play an important role in the prediction performance of the models. ML methods cannot outperform conventional LR in prediction models for rupture status of UIAs integrating clinical, aneurysm morphological, and hemodynamic parameters. KEY POINTS: • The addition of hemodynamic parameters can improve prediction performance for rupture status of unruptured intracranial aneurysms. • Machine learning algorithms cannot outperform conventional logistic regression in prediction models for rupture status integrating clinical, aneurysm morphological, and hemodynamic parameters. • Models integrating clinical, aneurysm morphological, and hemodynamic parameters may help choose the optimal management.

Development of novel EST-SSR markers for Rhododendron longipedicellatum (Ericaceae) and cross-amplification in two congeners.

PREMISE OF THE STUDY: To investigate the genetic background and population characteristics of Rhododendron longipedicellatum (Ericaceae), a newly discovered and critically endangered species, expressed sequence tag-simple sequence repeat markers were developed, and transferability was tested in two congeners, R. molle and R. simsii. METHODS AND RESULTS: Based on the transcriptome sequences of R. longipedicellatum, 102 primer sets were designed; 48 primer sets were successfully amplified, with 15 showing polymorphisms in 150 individuals from five extant populations of R. longipedicellatum. The number of alleles per locus ranged from four to 18, and the levels of observed and expected heterozygosity for the 15 loci varied from 0.255 to 0.913 and from 0.306 to 0.851, respectively. All 15 loci were found to amplify in R. molle and R. simsii. CONCLUSIONS: These polymorphic SSR markers can be used in conservation genetic and phylogeographic studies to elucidate the rarity and origin of R. longipedicellatum.

Development of novel EST-SSR markers for Phyllanthus emblica (Phyllanthaceae) and cross-amplification in two related species.

PREMISE OF THE STUDY: A novel set of EST-SSR markers was developed for Phyllanthus emblica (Phyllanthaceae) to investigate the genetic structure and gene flow, identify novel genes of interest, and develop markers for assisted breeding. METHODS AND RESULTS: Based on the transcriptome data of P. emblica, 83 EST-SSR primer pairs were designed; 52 primer pairs were successfully amplified, with 20 showing polymorphisms in 90 individuals from three populations of P. emblica. The number of alleles per locus varied from 11 to 44. The observed and expected levels of heterozygosity for the 20 loci ranged from 0.240 to 0.868 and 0.754 to 0.933, respectively. Cross-species amplification was successful for all 20 loci in each of the two related species, P. reticulatus and Leptopus chinensis. CONCLUSIONS: These markers will be valuable for studying the population genetics and for mining genes of P. emblica, and may be useful for studies of related species.

Study on Reproductive Biology of Rhododendron longipedicellatum: A Newly Discovered and Special Threatened Plant Surviving in Limestone Habitat in Southeast Yunnan, China.

Rhododendron longipedicellatum is a narrow endemic species and a subject of urgent demand in the domestic market and overseas. Its fascinating shapes, brilliantly gilvous flowers, and unusual flowering time endow this species with extremely high ornamental value. However, only five wild populations of R. longipedicellatum surviving in limestone habitat have been found through elaborate field investigation, and the number of the populations decreases further or is even confronted with risk of extinction due to the damage of human activities. To enhance the protection and utilization of R. longipedicellatum, this study systematically investigated several important aspects of reproductive biology, including floral syndrome, pollen viability and stigma receptivity, petal color reflectance, breeding system, and pollination biology. The results demonstrated that arched styles not only create obvious herkogamy that avoide self-pollination, but also effectively reduce rain damage to the intrinsic characteristics of the stigma surface secretions, promoting the female fitness of R. longipedicellatum in poor weather. Pollen viability maintained a high level over the flowering period. The reflectance spectrum of petals had two peaks at wavelengths of 360 and 580 nm. Tests of OCI, P/O and artificial pollination all indicated that R. longipedicellatum was self-compatible and that the breeding system was mixed mating. Geitonogamy mediated by Bombus braccatus was the primary pollination route in the natural environment, which suggested that the breeding system of R. longipedicellatum might be evolving from selfing to outcrossing. The pollination vector of R. longipedicellatum was very specific, in that only B. braccatus was confirmed to deliver pollen to the stigmas. Visitation frequency was influenced by the activity rhythms and resource requirements of the different castes (i.e., sex). B. braccatus workers were the most effective pollinators because of higher visitation frequency and more effective contribution to fruit production, whereas the presence of B. braccatus males might enhance pollen flow within the population to a certain extent. Finally, these findings not only provided a reliable theoretical basis for hybridization breeding of R. longipedicellatum as parents, but also laid a solid foundation for further molecular biology studies to more broadly reveal the mechanisms of its endangerment in the future.

Floral Scent Chemistry of Luculia yunnanensis (Rubiaceae), a Species Endemic to China with Sweetly Fragrant Flowers.

Luculia plants are famed ornamentals with sweetly fragrant flowers. Luculia yunnanensis Hu is an endemic plant from Yunnan Province, China. Headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to identify the volatile organic compounds (VOCs) of the different flower development stages of L. yunnanensis for the evaluation of floral volatile polymorphism. The results showed that a total of 40 compounds were identified at four different stages. The main aroma-active compounds were 3-carene, α-cubebene, α-copaene, δ-cadinene, and isoledene. Floral scent emission had the tendency to ascend first and descend in succession, reaching its peak level at the initial-flowering stage. The richest diversity of floral volatiles was detected at the full-flowering stage. Principal component analysis (PCA) indicated that the composition and its relative content of floral scent differed at the whole flower development stage. In comparison with the other two species of Luculia (L. pinceana and L. gratissima), the composition and its relative content of floral scent were also different among the tree species.

Volatile Organic Compounds Emissions from Luculia pinceana Flower and Its Changes at Different Stages of Flower Development.

Luculia plants are famed ornamental plants with sweetly fragrant flowers, of which L. pinceana Hooker, found primarily in Yunnan Province, China, has the widest distribution. Solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) was employed to identify the volatile organic compounds (VOCs) emitted from different flower development stages of L. pinceana for the evaluation of floral volatile polymorphism. Peak areas were normalized as percentages and used to determine the relative amounts of the volatiles. The results showed that a total of 39 compounds were identified at four different stages of L. pinceana flower development, including 26 at the bud stage, 26 at the initial-flowering stage, 32 at the full-flowering stage, and 32 at the end-flowering stage. The most abundant compound was paeonol (51%-83%) followed by (E,E)-α-farnesene, cyclosativene, and δ-cadinene. All these volatile compounds create the unique fragrance of L. pinceana flower. Floral scent emission offered tendency of ascending first and descending in succession, meeting its peak level at the initial-flowering stage. The richest diversity of floral volatile was detected at the third and later periods of flower development. Principal component analysis (PCA) indicated that the composition and its relative content of floral scent differed throughout the whole flower development. The result has important implications for future floral fragrance breeding of Luculia. L. pinceana would be adequate for a beneficial houseplant and has a promising prospect for development as essential oil besides for a fragrant ornamental owing to the main compounds of floral scent with many medicinal properties.

A set of novel microsatellite markers developed for Luculia yunnanensis (Rubiaceae), an endangered plant endemic to Yunnan, China.

The genus Luculia Sweet contains about five species of small trees or shrubs and is a member of the family Rubiaceae (tribe Cinchoneae). Luculia yunnanensis is an endangered ornamental shrub endemic to southwest China. Only two natural populations of L. yunnanensis exist in the wild according to our field investigation. It can be inferred that L. yunnanensis is facing a very high risk of extinction in the wild and an urgent conservation strategy is required. By using a modified biotin-sterptavidin capture method, 24 primer sets were identified in two wild populations. Of these primers, 11 displayed polymorphisms and 13 were monomorphic. The number of alleles per locus ranged from two to four, values for observed and expected heterozygosities ranged from 0.000 to 0.833 and from 0.431 to 0.771, with averages of 0.389 and 0.614, respectively. These markers will be useful for further investigation of conservation of resources, selecting parental types in cross-breeding, evolution of this species at the molecular level and related research in Luculia species.