Involvement of Protein Kinase A in Oxytocin Neuronal Activity in Rat Dams with Pup Deprivation

Neurochemical Research - Oxytocin (OT) neuronal activity is the key factor for breastfeeding and it can be disrupted by mother-baby separation. To explore cellular mechanisms underlying OT neuronal...     

Environmental and techno-economic analyses of bio-jet fuel produced from jatropha and castor oilseeds in China

Purpose

Bio-jet fuel derived from energy crops has been promoted by governments around the world through policies such as the Carbon Offsetting and Reduction Scheme for International Aviation. The environmental impact and techno-economic analysis of bio-jet fuel are particularly pertinent to China because China is under huge pressure to reduce emissions, endeavouring to meet bio-economic goals.

Methods

An LCA study was conducted on the production of bio-jet fuel from jatropha and castor by estimating the well-to-wake emissions and its economic impact. The functional unit was 1 MJ of bio-jet fuel, and field survey data was used in inventory analysis. A scenario analysis was performed to measure diverse conditions, including the planting conditions, planting regions, allocation methods, and hydrogen sources. A techno-economic analysis that combined the production costs and co-product credits was performed to calculate the minimum bio-jet fuel selling price (MJSP) based on a plant capacity of 2400 metric tonnes of feedstock per day.

Results and discussion

Compared to the environmental impacts to the fossil jet fuel, the use of biofuel would reduce the majority environmental impacts by 36–85%, when a 1:1 displacement of fossil jet fuel is considered, though the human toxicity potential impact was 100% higher. The scenario analysis indicated that (i) planting castor in harsh and unevenly distributed conditions and jatropha in stable or fertile conditions can leverage their respective advantage; (ii) the global warming potential (GWP) from castor planting in the region of north-east China ranges from 34 to 48 g CO₂ eq/MJ; (iii) the GWP produced through the steam methane reforming process can be reduced by 16–17%, using advances in technological processes. The MJSP for fuel produced from jatropha and castor under the basic scenario is estimated to be 5.68 and 4.66 CNY/kg, respectively, which falls within the current market price range of 4.5–7.5 CNY/kg.

Conclusions

Bio-jet fuel from jatropha and castor oilseeds offers potential environmental benefits if they can reduce fossil jet fuel on an energy-equivalent basis. However, these benefits are likely to be reduced by the rebound effect of the fuel market. Future research is needed to better understand the magnitude of the rebound effect in China and what policy interventions can be implemented to alleviate it. Scenario analysis demonstrated the feasibility and potential of bio-jet fuel development from multiple perspectives and technological progress are conducive to the realization of environmental protection policies.

     

Divergent DNA methylation contributes to duplicated gene evolution and chilling response in tea plants

The tea plant (Camellia sinensis) is a thermophilic cash crop and contains a highly duplicated and repeat-rich genome. It is still unclear how DNA methylation regulates the evolution of duplicated genes and chilling stress in tea plants. We therefore generated a single-base-resolution DNA methylation map of tea plants under chilling stress. We found that, compared with other plants, the tea plant genome is highly methylated in all three sequence contexts, including CG, CHG and CHH (where H = A, T, or C), which is further proven to be correlated with its repeat content and genome size. We show that DNA methylation in the gene body negatively regulates the gene expression of tea plants, whereas non-CG methylation in the flanking region enables a positive regulation of gene expression. We demonstrate that transposable element-mediated methylation dynamics significantly drives the expression divergence of duplicated genes in tea plants. The DNA methylation and expression divergence of duplicated genes in the tea plant increases with evolutionary age and selective pressure. Moreover, we detect thousands of differentially methylated genes, some of which are functionally associated with chilling stress. We also experimentally reveal that DNA methyltransferase genes of tea plants are significantly downregulated, whereas demethylase genes are upregulated at the initial stage of chilling stress, which is in line with the significant loss of DNA methylation of three well-known cold-responsive genes at their promoter and gene body regions. Overall, our findings underscore the importance of DNA methylation regulation and offer new insights into duplicated gene evolution and chilling tolerance in tea plants.     

Target-specific mutations efficiency at multiple loci of CRISPR/Cas9 system using one sgRNA in soybean

Soybean has a palaeopolyploid genome with nearly 75% of the genes present in multiple copies. Although the CRISPR/Cas9 system has been employed in soybean to generate site-directed mutagenesis, a systematical assessment of mutation efficiency of the CRISPR/Cas9 system for the multiple-copy genes is still urgently needed. Here, we successfully optimize one sgRNA CRISPR/Cas9 system in soybean by testing the efficiency, pattern, specificity of the mutations at multiple loci of GmFAD2 and GmALS. The results showed that simultaneous site-directed mutagenesis of two homoeologous loci by one sgRNA, the mutation frequency in the T0 generation were 64.71% for GmPDS, 60.0% for GmFAD2 and 42.86% for GmALS, respectively. The chimeric and heterozygous mutations were dominant types. Moreover, association of phenotypes with mutation pattern at target loci of GmPDS11 and GmPDS18 could help us further demonstrate that the CRISPR/Cas9 system can efficiently generate target specific mutations at multiple loci using one sgRNA in soybean, albeit with a relatively low transformation efficiency.

     

Cytological and morphology characteristics of natural microsporogenesis within Camellia oleifera

Camellia oleifera is believed to exhibit a complex intraspecific polyploidy phenomenon. Abnormal microsporogenesis can promote the formation of unreduced gametes in plants and lead to sexual polyploidy, so it is hypothesized that improper meiosis probably results in the formation of natural polyploidy in Camellia oleifera. In this study, based on the cytological observation of meiosis in pollen mother cells (PMCs), we found natural 2n pollen for the first time in Camellia oleifera, which may lead to the formation of natural polyploids by sexual polyploidization. Additionally, abnormal cytological behaviour during meiosis, including univalent chromosomes, extraequatorial chromosomes, early segregation, laggard chromosomes, chromosome stickiness, asynchronous meiosis and deviant cytokinesis (monad, dyads, triads), was observed, which could be the cause of 2n pollen formation. Moreover, we confirmed a relationship among the length–width ratio of flower buds, stylet length and microsporogenesis. This result suggested that we can immediately determine the microsporogenesis stages by phenotypic characteristics, which may be applicable to breeding advanced germplasm in Camellia oleifera.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12298-021-01002-5.     

鸡粪有机肥对设施菜地土壤重金属和微生物群落结构的影响

通过田间试验,研究在设施菜地上施用不同剂量的鸡粪有机肥对土壤-植物系统中重金属的累积、重金属有效性和土壤微生物群落结构的影响,进一步探讨土壤微生物群落结构与土壤重金属之间的相关关系。结果表明,与对照相比,施用有机肥可提高小白菜地上部生物量,其中施肥量为60 t/hm²时值最大,增幅为59.92%;小白菜地上部Cd、Cr、Cu、Zn和As含量均大幅增加,但Pb含量无明显变化。土壤重金属Cd、Cr、Cu、Zn和As的全量均随鸡粪有机肥施加量的增加而增大,最高增幅分别为21.30%、21.58%、17.40%、19.40%和17.43%,出现明显的累积现象;施用有机肥均增加了土壤Cd、Cr、Cu、Zn和As的有效态含量,而Pb的全量和有效态含量无显著变化;除重金属Pb外,不同重金属元素全量与有效态含量均显著正相关,其中元素Zn的全量与有效态含量相关性最强。磷脂脂肪酸（PLFA）分析结果表明,土壤中含量较高的PLFA为16：0、18：1ω7c、10Me16：0和18：1ω9c,土壤微生物总PLFA和各类群PLFA含量均呈现M0.5 > M1 > CK > M2 > M4;相关性分析结果表明,土壤Cu、As全量和Cd、Cr、Cu、As有效态含量与微生物总PLFA和各类群PLFA含量均呈现显著负相关关系,其中有效态Cr和Cu含量对微生物群落结构的影响最为显著。     

“共轭聚合物-产电菌”复合生物电极构建及其在微生物燃料电池中的应用

微生物燃料电池(Microbial fuel cell,MFC)作为一种生物电化学装置,在可再生能源生产和废水处理方面的巨大潜力已引起广泛关注。然而MFC面临输出功率低、欧姆内阻高以及启动时间长等问题,极大限制了其在实际工程中的应用。MFC中阳极是微生物附着的载体,对电子的产生及传递起着关键作用,开发优质的生物电极已发展成为改善MFC性能的有效途径。共轭聚合物具有成本低、电导率高、化学稳定性及生物相容性好等优点,利用共轭聚合物修饰生物电极结构,可以实现大比表面积、缩短电荷转移路径,从而实现高效生物电化学性能。同时,纳米级共轭聚合物包覆细菌,可以使细菌产生的电子有效地传递到电极。文中综述了最近报道的共轭聚合物在MFC中的应用,重点介绍了共轭聚合物修饰的MFC阳极,系统分析了共轭聚合物的优点及局限性,以及这些高效复合生物电极如何解决MFC应用中存在的低输出功率、高欧姆内阻及长启动时间等问题。     

DNA水凝胶的制备及应用

脱氧核糖核酸(Deoxyribonucleic acid,DNA)不仅可作为生物遗传的物质基础,又以其可编程性、功能多样性、生物相容性和生物可降解性等优点,在生物材料的构建方面表现出巨大的潜力。DNA水凝胶是一种主要由DNA参与形成的三维网状聚合物材料,同时因其保留的DNA生物性能与自身骨架的机械性能的完美融合使得它成为近年来最受关注的新兴功能高分子材料之一。目前,基于各种功能核酸序列或通过结合不同的功能材料制备的单组分或多组分DNA水凝胶,已广泛用于生物医学、分子检测及环境保护的研究或应用领域中。文中主要总结了近十几年来DNA水凝胶制备方法上的研究进展,探讨了DNA水凝胶的分类策略,并进一步综述了DNA水凝胶在药物运输、生物传感、细胞培养等方面的应用研究。最后对DNA水凝胶未来的发展方向以及可能面临的挑战进行了展望。