Photovoltaic-driven Ni(ii)/Ni(iii) redox mediator for the valorization of PET plastic waste with hydrogen production.

Electrocatalytic valorization of PET plastic waste provides an appealing route by converting intermittent renewable energy into valuable chemicals and high-energy fuels. Normally, anodic PET hydrolysate oxidation and cathodic water reduction reactions occur simultaneously in the same time and space, which increases the challenges for product separation and operational conditions. Although these problems can be addressed by utilizing membranes or diaphragms, the parasitic cell resistance and high overall cost severely restrict their future application. Herein, we introduce a Ni(ii)/Ni(iii) redox mediator to decouple these reactions into two independent processes: an electrochemical process for water reduction to produce hydrogen fuel assisted by the oxidation of the Ni(OH)2 electrode into the NiOOH counterpart, followed subsequently by a spontaneous chemical process for the valorization of PET hydrolysate to produce formic acid with a high faradaic efficiency of ∼96% by the oxidized NiOOH electrode. This decoupling strategy enables the electrochemical valorization of PET plastic waste in a membrane-free system to produce high-value formic acid and high-purity hydrogen production. This study provides an appealing route to facilitate the transformation process of PET plastic waste into high-value products with high efficiency, low cost and high purity.

Advances in the Modulation of Potato Tuber Dormancy and Sprouting.

The post-harvest phase of potato tuber dormancy and sprouting are essential in determining the economic value. The intricate transition from dormancy to active growth is influenced by multiple factors, including environmental factors, carbohydrate metabolism, and hormonal regulation. Well-established environmental factors such as temperature, humidity, and light play pivotal roles in these processes. However, recent research has expanded our understanding to encompass other novel influences such as magnetic fields, cold plasma treatment, and UV-C irradiation. Hormones like abscisic acid (ABA), gibberellic acid (GA), cytokinins (CK), auxin, and ethylene (ETH) act as crucial messengers, while brassinosteroids (BRs) have emerged as key modulators of potato tuber sprouting. In addition, jasmonates (JAs), strigolactones (SLs), and salicylic acid (SA) also regulate potato dormancy and sprouting. This review article delves into the intricate study of potato dormancy and sprouting, emphasizing the impact of environmental conditions, carbohydrate metabolism, and hormonal regulation. It explores how various environmental factors affect dormancy and sprouting processes. Additionally, it highlights the role of carbohydrates in potato tuber sprouting and the intricate hormonal interplay, particularly the role of BRs. This review underscores the complexity of these interactions and their importance in optimizing potato dormancy and sprouting for agricultural practices.

Retinal detachment with multiple macrocysts in Stickler syndrome: case report and review of the literature.

Background: Stickler syndrome is a hereditary connective tissue disorder associated with ocular, orofacial, musculoskeletal, and auditory impairments. Its main clinical characteristics include retinal detachment, hearing loss, and midface underdevelopment. In clinical practice, macrocyst is rarely reported in retinal detachment cases with Stickler syndrome. Case presentation: We report the case of a 7-year-old child who developed a rhegmatogenous retinal detachment (RRD) in the right eye, accompanied by multiple peripheral macrocysts. The detachment was successfully surgically repaired with vitrectomy, retinal laser photocoagulation, cryotherapy and silicone oil tamponade. During the operation, a mini-retinectomy in the outer layer of each macrocyst was made for vesicular drainage and retinal reattachment. Genetic testing identified a pathogenic point mutation variant (c.1693C>T; p.Arg565Cys) in exon 26 of the COL2A1 gene. Six-months after the operation, the retina remained attached with improvement of best corrected visual acuity to 20/200. Conclusion: Patients with Stickler syndrome may develop RRD of different severity. Macrocyst is rarely reported in previous literature of Stickler syndrome. In this case report, we share our experience in treating with multiple macrocysts in RRD and emphasize the importance of periodic follow-up for patients with Stickler syndrome.

Large-scale gene expression alterations introduced by structural variation drive morphotype diversification in Brassica oleracea.

Brassica oleracea, globally cultivated for its vegetable crops, consists of very diverse morphotypes, characterized by specialized enlarged organs as harvested products. This makes B. oleracea an ideal model for studying rapid evolution and domestication. We constructed a B. oleracea pan-genome from 27 high-quality genomes representing all morphotypes and their wild relatives. We identified structural variations (SVs) among these genomes and characterized these in 704 B. oleracea accessions using graph-based genome tools. We show that SVs exert bidirectional effects on the expression of numerous genes, either suppressing through DNA methylation or promoting probably by harboring transcription factor-binding elements. The following examples illustrate the role of SVs modulating gene expression: SVs promoting BoPNY and suppressing BoCKX3 in cauliflower/broccoli, suppressing BoKAN1 and BoACS4 in cabbage and promoting BoMYBtf in ornamental kale. These results provide solid evidence for the role of SVs as dosage regulators of gene expression, driving B. oleracea domestication and diversification.

OcBSA: An NGS-based bulk segregant analysis tool for outcross populations.

Constructing inbred lines for self-incompatible species and species with long generation times is challenging, making the use of F1 outcross/segregating populations the main strategy for genetic studies of such species. However, there is a lack of dedicated algorithms/tools for rapid quantitative trait locus (QTL) mapping using the F1 populations. To this end, we have designed and developed an algorithm/tool called OcBSA specifically for QTL mapping of F1 populations. OcBSA transforms the four-haplotype inheritance problem from the two heterozygous diploid parents of the F1 population into the two-haplotype inheritance problem common in current genetic studies by removing the two haplotypes from the heterozygous parent that do not contribute to phenotype segregation in the F1 population. Testing of OcBSA on 1800 simulated F1 populations demonstrated its advantages over other currently available tools in terms of sensitivity and accuracy. In addition, the broad applicability of OcBSA was validated by QTL mapping using seven reported F1 populations of apple, pear, peach, citrus, grape, tea, and rice. We also used OcBSA to map the QTL for flower color in a newly constructed F1 population of potato generated in this study. The OcBSA mapping result was verified by the insertion or deletion markers to be consistent with a previously reported locus harboring the ANTHOCYANIN 2 gene, which regulates potato flower color. Taken together, these results highlight the power and broad utility of OcBSA for QTL mapping using F1 populations and thus a great potential for functional gene mining in outcrossing species. For ease of use, we have developed both Windows and Linux versions of OcBSA, which are freely available at: https://gitee.com/Bioinformaticslab/OcBSA.

Transcriptome Analysis Reveals the Molecular Mechanisms of BR Negative Regulatory Factor StBIN2 Maintaining Tuber Dormancy.

Potato is an important food crop. After harvest, these tubers will undergo a period of dormancy. Brassinosteroids (BRs) are a new class of plant hormones that regulate plant growth and seed germination. In this study, 500 nM of BR was able to break the dormancy of tubers. Additionally, exogenous BR also upregulated BR signal transduction genes, except for StBIN2. StBIN2 is a negative regulator of BR, but its specific role in tuber dormancy remains unclear. Transgenic methods were used to regulate the expression level of StBIN2 in tubers. It was demonstrated that the overexpression of StBIN2 significantly prolonged tuber dormancy while silencing StBIN2 led to premature sprouting. To further investigate the effect of StBIN2 on tuber dormancy, RNA-Seq was used to analyze the differentially expressed genes in OE-StBIN2, RNAi-StBIN2, and WT tubers. The results showed that StBIN2 upregulated the expression of ABA signal transduction genes but inhibited the expression of lignin synthesis key genes. Meanwhile, it was also found that StBIN2 physically interacted with StSnRK2.2 and StCCJ9. These results indicate that StBIN2 maintains tuber dormancy by mediating ABA signal transduction and lignin synthesis. The findings of this study will help us better understand the molecular mechanisms underlying potato tuber dormancy and provide theoretical support for the development of new varieties using related genes.

StSN2 interacts with the brassinosteroid signaling suppressor StBIN2 to maintain tuber dormancy.

After harvest, potato tubers undergo an important period of dormancy, which significantly impacts potato quality and seed vigor. StSN2 has been reported as a key gene for maintaining tuber dormancy; in this study, we explored the molecular mechanism by which StSN2 maintains dormancy. StBIN2 was first identified as a candidate protein that interacts with StSN2 by co-immunoprecipitation/mass spectrometry, and both qPCR and enzyme activity experiments showed that StSN2 can promote the StBIN2 expression and activity. In addition, the interaction between StSN2 and StBIN2 was verified by yeast two-hybrid, luciferase complementation experiments and co-immunoprecipitation. Bioinformatics analysis and site-directed mutagenesis confirmed the critical role of cysteine residues of StBIN2 in its binding to StSN2. Similar to that of StSN2, overexpression of StBIN2 extended the dormancy of potato tuber. Interaction between StSN2 and StBIN2 increased the activity of the StBIN2 enzyme, inhibited the expression of StBZR1, and suppressed BR signaling. On the contrary, this interaction promoted the expression of StSnRK2.2/2.3/2.4/2.6 and StABI5, key genes of ABA signaling, and the phosphorylation of StSnRK2.3, thereby promoting ABA signaling. Altogether, our results indicate that StSN2 interacts with StBIN2 through key cysteine residues and StBIN2 maintains tuber dormancy by affecting ABA and BR signaling. Findings of this research offer new insights into the molecular mechanism by which StSN2 maintains potato tuber dormancy through interaction with StSIN2 and provide guidance for potato improvement.

StBIN2 Positively Regulates Potato Formation through Hormone and Sugar Signaling.

Potato is an important food crop worldwide. Brassinosteroids (BRs) are widely involved in plant growth and development, and BIN2 (brassinosteroid insensitive 2) is the negative regulator of their signal transduction. However, the function of BIN2 in the formation of potato tubers remains unclear. In this study, transgenic methods were used to regulate the expression level of StBIN2 in plants, and tuber related phenotypes were analyzed. The overexpression of StBIN2 significantly increased the number of potatoes formed per plant and the weight of potatoes in transgenic plants. In order to further explore the effect of StBIN2 on the formation of potato tubers, this study analyzed BRs, ABA hormone signal transduction, sucrose starch synthase activity, the expression levels of related genes, and interacting proteins. The results show that the overexpression of StBIN2 enhanced the downstream transmission of ABA signals. At the same time, the enzyme activity of the sugar transporter and the expression of synthetic genes were increased in potato plants overexpressing StBIN2, which also demonstrated the upregulation of sucrose and the expression of the starch synthesis gene. Apparently, StBIN2 affected the conversion and utilization of key substances such as glucose, sucrose, and starch in the process of potato formation so as to provide a material basis and energy preparation for forming potatoes. In addition, StBIN2 also promoted the expression of the tuber formation factors StSP6A and StS6K. Altogether, this investigation enriches the study on the mechanism through which StBIN2 regulates potato tuber formation and provides a theoretical basis for achieving a high and stable yield of potato.

Transcriptome and metabolome analysis reveals the effect of flavonoids on flower color variation in Dendrobium nobile Lindl.

Introduction: Dendrobium nobile L. is a rare orchid plant with high medicinal and ornamentalvalue, and extremely few genetic species resources are remaining in nature. In the normal purple flower population, a type of population material with a white flower variation phenotype has been discovered, and through pigment component determination, flavonoids were preliminarily found to be the main reason for the variation. Methods: This study mainly explored the different genes and metabolites at different flowering stages and analysed the flower color variation mechanism through transcriptome- and flavonoid-targeted metabolomics. The experimental materials consisted of two different flower color phenotypes, purple flower (PF) and white flower (WF), observed during three different periods. Results and discussion: The results identified 1382, 2421 and 989 differentially expressed genes (DEGs) in the white flower variety compared with the purple flower variety at S1 (bud stage), S2 (chromogenic stage) and S3 (flowering stage), respectively. Among these, 27 genes enriched in the ko00941, ko00942, ko00943 and ko00944 pathways were screened as potential functional genes affecting flavonoid synthesis and flower color. Further analysis revealed that 15 genes are potential functional genes that lead to flavonoid changes and flower color variations. The metabolomics results at S3 found 129 differentially accumulated metabolites (DAMs), which included 8 anthocyanin metabolites, all of which (with the exception of delphinidin-3-o-(2'''-o-malonyl) sophoroside-5-o-glucoside) were found at lower amounts in the WF variety compared with the PF variety, indicating that a decrease in the anthocyanin content was the main reason for the inability to form purple flowers. Therefore, the changes in 19 flavone and 62 flavonol metabolites were considered the main reasons for the formation of white flowers. In this study, valuable materials responsible for flower color variation in D. nobile were identified and further analyzed the main pathways and potential genes affecting changes in flavonoids and the flower color. This study provides a material basis and theoretical support for the hybridization and molecular-assisted breeding of D. nobile.

The energy conservation and emission reduction co-benefits of China's emission trading system.

Emission Trading System (ETS) is an innovative practice under the progress of green development in China. It is also an important method for China to achieve market-oriented environmental governance in ecological civilization construction. The ETS pilot policy has implemented for more than 10 years. However, the co-benefits of ETS pilot policy by the integration of energy consumption, carbon and sulfur dioxide emissions, and wastewater has not been evaluated. In order to fill this gap, we use the 2003-2017 annual data of 30 China's provinces (municipalities and autonomous regions), and utilize the Difference-in-Differences (DID) model and Propensity Score Matching (PSM-DID) methodology to evaluate the co-benefits of ETS pilot policy on energy conservation and emission reduction. We find that the ETS pilot policy significantly promote energy conservation and emission reduction. Eastern and central China have significantly benefited from the policy, while the western China has not due to the limited technology and innovation as well as an imbalance of the industrial structure. The results provide the policy reference for China's government and institutions as well as the governments and institutions around the world to fulfill their commitments to save energy and reduce emissions, and early achieve the carbon peaking and carbon neutralization.

Pleiotrophin ameliorates age-induced adult hippocampal neurogenesis decline and cognitive dysfunction.

Cognitive impairment has been associated with an age-related decline in adult hippocampal neurogenesis (AHN). The molecular basis of declining neurogenesis in the aging hippocampus remains to be elucidated. Here, we show that pleiotrophin (PTN) expression is decreased with aging in neural stem and progenitor cells (NSPCs). Mice lacking PTN exhibit impaired AHN accompanied by poor learning and memory. Mechanistically, we find that PTN engages with protein tyrosine phosphatase receptor type Z1 (PTPRZ1) to promote NSPC proliferation and differentiation by activating AKT signaling. PTN overexpression or pharmacological activation of AKT signaling in aging mice restores AHN and alleviates relevant memory deficits. Importantly, we also find that PTN overexpression improves impaired neurogenesis in senescence-accelerated mouse prone 8 (SAMP8) mice. We further confirm that PTN is required for enriched environment-induced increases in AHN. These results corroborate the significance of AHN in aging and reveal a possible therapeutic intervention by targeting PTN.

Impact of family functioning on mental health problems of college students in China during COVID-19 pandemic and moderating role of coping style: a longitudinal study.

BACKGROUND: During the COVID-19 pandemic, college students were required to stay at home and maintain social distance for the entire spring semester of 2020. There is little research on how family functioning influenced mental health problems and how coping styles moderated the relationship between family functioning and mental health problems among college students during their stay-at-home period. METHODS: A total of 13,462 college students (age = 16-29 years) completed four online surveys between February and October 2020, namely the outbreak phase, remission phase, online study phase, and school reopening phase in Guangdong Province, China. Family functioning was assessed by the Family APGAR; coping styles were assessed by the Simplified Coping Style Questionnaire (SCSQ), depression symptoms and anxiety symptoms were evaluated by the Patient Health Questionnaire (PHQ-9) and the Generalized Anxiety Disorder Scale (GAD-7) respectively. Generalized estimating equations were used to assess associations between variables, the logit link function was used to estimate the odds ratio of different subgroups, the Newton-Raphson method was used to estimate parameters, and the Wald test was used to test the main effect and the interaction effect. RESULTS: The incidence rates of depression increased during the stay-at-home period from 33.87%, 95% CI (29.88%, 38.10%) to 40.08% 95% CI (35.76%, 44.55%) after schools reopened, χ2 = 193.68, p < 0.001. The incidence rates of anxiety increased from 17.45%, 95% CI (14.59%, 20.73%) to 26.53%, 95% CI (16.94%, 23.67%) over the entire period, χ2 = 195.74, p < 0.001. The percentages of students with highly functional, moderately dysfunctional and severely dysfunctional family functioning were 48.23%, 43.91 and 7.86% at T1 and 46.20%, 45.28%, and 8.52 at T4, respectively. The percentage of subjects with active coping style was 23.9%, negative coping style was 17.4%, strong response coping was 26.9%, and weak response coping was 31.7%. The incidence rate of depression and anxiety for different family functioning groups varied at different time points, and the interaction effect was significant (χ2 = 52.97, p < 0.001 and χ2 = 51.25, p < 0.001, respectively). The incidence rate of depression and anxiety for different family functioning groups with different coping styles also varied at different time points, the interaction effect was likewise significant (χ2 = 862.09, p < 0.001 and χ2 = 583.29, p < 0.001, respectively). CONCLUSIONS: Having a severely dysfunctional family and a negative coping style increase the incidence rates of depression and anxiety. These findings highlight the importance of paying special attention to college students' family functioning and promoting appropriate coping strategies during and after COVID-19.

Fine mapping of meiotic crossovers in Brassica oleracea reveals patterns and variations depending on direction and combination of crosses.

Meiotic recombination is crucial for assuring proper segregation of parental chromosomes and generation of novel allelic combinations. As this process is tightly regulated, identifying factors influencing rate, and distribution of meiotic crossovers (COs) is of major importance, notably for plant breeding programs. However, high-resolution recombination maps are sparse in most crops including the Brassica genus and knowledge about intraspecific variation and sex differences is lacking. Here, we report fine-scale resolution recombination landscapes for 10 female and 10 male crosses in Brassica oleracea, by analyzing progenies of five large four-way-cross populations from two reciprocally crossed F1s per population. Parents are highly diverse inbred lines representing major crops, including broccoli, cauliflower, cabbage, kohlrabi, and kale. We produced approximately 4.56T Illumina data from 1248 progenies and identified 15 353 CO across the 10 reciprocal crosses, 51.13% of which being mapped to <10 kb. We revealed fairly similar Mb-scale recombination landscapes among all cross combinations and between the sexes, and provided evidence that these landscapes are largely independent of sequence divergence. We evidenced strong influence of gene density and large structural variations on CO formation in B. oleracea. Moreover, we found extensive variations in CO number depending on the direction and combination of the initial parents crossed with, for the first time, a striking interdependency between these factors. These data improve our current knowledge on meiotic recombination and are important for Brassica breeders.

Engineering Electrodes with Robust Conducting Hydrogel Coating for Neural Recording and Modulation.

Coating conventional metallic electrodes with conducting polymers has enabled the essential characteristics required for bioelectronics, such as biocompatibility, electrical conductivity, mechanical compliance, and the capacity for structural and chemical functionalization of the bioelectrodes. However, the fragile interface between the conducting polymer and the electrode in wet physiological environment greatly limits their utility and reliability. Here, a general yet reliable strategy to seamlessly interface conventional electrodes with conducting hydrogel coatings is established, featuring tissue-like modulus, highly-desirable electrochemical properties, robust interface, and long-term reliability. Numerical modeling reveals the role of toughening mechanism, synergy of covalent anchorage of long-chain polymers, and chemical cross-linking, in improving the long-term robustness of the interface. Through in vivo implantation in freely-moving mouse models, it is shown that stable electrophysiological recording can be achieved, while the conducting hydrogel-electrode interface remains robust during the long-term low-voltage electrical stimulation. This simple yet versatile design strategy addresses the long-standing technical challenges in functional bioelectrode engineering, and opens up new avenues for the next-generation diagnostic brain-machine interfaces.

Genetic dissection of morphological variation in rosette leaves and leafy heads in cabbage (Brassica oleracea var. capitata).

KEY MESSAGE: Correlations between morphological traits of cabbage rosette leaves and heads were found. Genome-wide association studies of these traits identified 50 robust quantitative trait loci in multiple years. Half of these loci affect both organs. Cabbage (Brassica oleracea var. capitata) is an economically important vegetable crop cultivated worldwide. Cabbage plants go through four vegetative stages: seedling, rosette, folding and heading. Rosette leaves are the largest leaves of cabbage plants and provide most of the energy needed to produce the leafy head. To understand the relationship and the genetic basis of leaf development and leafy head formation, 308 cabbage accessions were scored for rosette leaf and head traits in three-year field trials. Significant correlations were found between morphological traits of rosette leaves and heads, namely leaf area with the head area, height and width, and leaf width with the head area and head height, when heads were harvested at a fixed number of days after sowing. Fifty robust quantitative trait loci (QTLs) for rosette leaf and head traits distributed over all nine chromosomes were identified with genome-wide association studies. All these 50 loci were identified in multiple years and generally affect multiple traits. Twenty-five of the QTL were associated with both rosette leaf and leafy head traits. We discuss thirteen candidate genes identified in these QTL that are expressed in heading leaves, with an annotation related to auxin and other phytohormones, leaf development, and leaf polarity that likely play a role in leafy head development or rosette leaf expansion.

Integrated 3D printing of flexible electroluminescent devices and soft robots.

Flexible and stretchable light emitting devices are driving innovation in myriad applications, such as wearable and functional electronics, displays and soft robotics. However, the development of flexible electroluminescent devices via conventional techniques remains laborious and cost-prohibitive. Here, we report a facile and easily-accessible route for fabricating a class of flexible electroluminescent devices and soft robotics via direct ink writing-based 3D printing. 3D printable ion conducting, electroluminescent and insulating dielectric inks were developed, enabling facile and on-demand creation of flexible and stretchable electroluminescent devices with good fidelity. Robust interfacial adhesion with the multilayer electroluminescent devices endowed the 3D printed devices with attractive electroluminescent performance. Integrated our 3D printed electroluminescent devices with a soft quadrupedal robot and sensing units, an artificial camouflage that can instantly self-adapt to the environment by displaying matching color was fabricated, laying an efficient framework for the next generation soft camouflages.

Environment-Resistant Organohydrogel-Based Sensor Enables Highly Sensitive Strain, Temperature, and Humidity Responses.

Conductive hydrogels have been extensively used in wearable skin sensors owing to their outstanding flexibility, tissuelike compliance, and biocompatibility. However, the dehydration and embrittlement of hydrogels can result in sensitivity loss or even invalidation, restraining their wearable applications in external environments, especially at low temperatures and in arid environments. Herein, an environment-resistant organohydrogel is developed for multifunctional sensors. A double-network organohydrogel based on hyaluronic acid and poly(acrylic acid-co-acrylamide) is developed, and glycerol is introduced into the organohydrogel network via a solvent displacement strategy. Owing to the water-locking effects of glycerol and tough polymeric backbone, the resultant organohydrogel not only exhibits stable tensibility but also maintains excellent flexibility and stable conductivity with the environment-resistant properties, including freezing resistance against -30 °C and moisture retention at 4% relative humidity in a high temperature of 60 °C. Moreover, a series of organohydrogel-based sensors and an array device are developed to achieve highly sensitive strain, temperature, and humidity responses and exhibit a high gauge factor of 10.79 in the strain-sensitive test. This work develops a universal ionic skin based on organohydrogels to be applied to wearable sensors for health monitoring.

Prevalence and associated factors of depression, anxiety and suicidality among Chinese high school E-learning students during the COVID-19 lockdown.

BACKGROUND: The outbreak of Coronavirus disease (COVID-19) in 2019 and the resulting quarantine may have increased the prevalence of mental health problems in adolescents. The aim of this study was to explore the association between the effects of home-based learning during the pandemic and the risks of depression, anxiety, and suicidality among junior and senior high school students. METHODS: An online survey using Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder (GAD-7) was conducted between 12 to 30 April 2020, on a total of 39,751 students. Multivariable logistic regression analysis was used to analyze the risk factors of associated depression, anxiety and suicidality during the pandemic. RESULTS: Prevalence of depression, anxiety symptoms and suicidality found was 16.3% (95% CI: 16.0, 16.7), 10.3% (95% CI: 10.0, 10.6) and 20.3% (95% CI: 19.9, 20.7), respectively. Participants with female gender and in junior high school, with poor overall sleep quality and poor academic performance and very worried about being infected during COVID-19 were highly associated with the risk of depression, anxiety symptoms and suicidal ideation (all P<0.001). CONCLUSIONS: Prevalence of self-reported mental health problems for adolescents using home-based distance learning was high. Implementing measures (e.g., wearing face masks) and spending only moderate time focusing on COVID-19-related information could be protective factors for mental health. These results provide suggestions for teachers and policy makers regarding adolescent improving sleep quality (sufficient sleep) and academic performance and reducing worry about pandemic during quarantine to prevent mental health problems.

Evidence for two domestication lineages supporting a middle-eastern origin for Brassica oleracea crops from diversified kale populations.

Brassica oleracea displays enormous phenotypic variation, including vegetables like cabbage, broccoli, cauliflower, kohlrabi, kales etc. Its domestication has not been clarified, despite several genetic studies and investigations of ancient literature. We used 14 152 high-quality SNP markers for population genetic studies and species-tree estimation (treating morphotypes as "species") using SVD-quartets coalescent-modelling of a collection of 912 globally distributed accessions representing ten morphotypes of B. oleracea, wild B. oleracea accessions and nine related C9 Brassica species. Our genealogical tree provided evidence for two domestication lineages, the "leafy head" lineage (LHL) and the "arrested inflorescence" lineage (AIL). It also showed that kales are polyphyletic with regards to B. oleracea morphotypes, which fits ancient literature describing highly diverse kale types at around 400 BC. The SVD-quartets species tree topology showed that different kale clades are sister to either the LHL or the AIL. Cabbages from the middle-east formed the first-branching cabbage-clade, supporting the hypothesis that cabbage domestication started in the middle-east, which is confirmed by archeological evidence and historic writings. We hypothesize that cabbages and cauliflowers stem from kales introduced from Western Europe to the middle-east, possibly transported with the tin-trade routes in the Bronze age, to be re-introduced later into Europe. Cauliflower is the least diverse morphotype showing strong genetic differentiation with other morphotypes except broccoli, suggesting a strong genetic bottleneck. Genetic diversity reduced from landraces to modern hybrids for almost all morphotypes. This comprehensive Brassica C-group germplasm collection provides valuable genetic resources and a sound basis for B. oleracea breeding.

The Cysteine-Rich Peptide Snakin-2 Negatively Regulates Tubers Sprouting through Modulating Lignin Biosynthesis and H2O2 Accumulation in Potato.

Potato tuber dormancy is critical for the post-harvest quality. Snakin/Gibberellic Acid Stimulated in Arabidopsis (GASA) family genes are involved in the plants' defense against pathogens and in growth and development, but the effect of Snakin-2 (SN2) on tuber dormancy and sprouting is largely unknown. In this study, a transgenic approach was applied to manipulate the expression level of SN2 in tubers, and it demonstrated that StSN2 significantly controlled tuber sprouting, and silencing StSN2 resulted in a release of dormancy and overexpressing tubers showed a longer dormant period than that of the control. Further analyses revealed that the decrease expression level accelerated skin cracking and water loss. Metabolite analyses revealed that StSN2 significantly down-regulated the accumulation of lignin precursors in the periderm, and the change of lignin content was documented, a finding which was consistent with the precursors' level. Subsequently, proteomics found that cinnamyl alcohol dehydrogenase (CAD), caffeic acid O-methyltransferase (COMT) and peroxidase (Prx), the key proteins for lignin synthesis, were significantly up-regulated in silencing lines, and gene expression and enzyme activity analyses also supported this effect. Interestingly, we found that StSN2 physically interacts with three peroxidases catalyzing the oxidation and polymerization of lignin. In addition, SN2 altered the hydrogen peroxide (H2O2) content and the activities of superoxide dismutase (SOD) and catalase (CAT). These results suggest that StSN2 negatively regulates lignin biosynthesis and H2O2 accumulation, and ultimately inhibits the sprouting of potato tubers.