Differentiation of Rickettsia japonica by Restriction Endonuclease Fragment Length Polymorphism Using Products of Polymerase Chain Reaction Amplification with Rickettsia rickettsii 190-Kilodalton Surface Antigen Gene Primers

Restriction fragment length polymorphism of polymerase chain reaction (PCR) amplification products differentiated Rickettsia japonica, a causative agent of Oriental spotted fever, from other spotted fever group (SFG) rickettsiae. Primer pair Rr190. 70p and Rr190. 602n of R. rickettsii 190-kDa antigen gene sequence primed genomic DNAs obtained from R. japonica, type strain YH and strains NT, NK, YKI, and TKN. The products were cleaved by PstI but not by AfaI restriction endonuclease. The PstI digestion pattern of PCR-products amplified from all strains of R. japonica was identical and easily differentiated from that of other SFG rickettsiae. The present study demonstrated a genotypic difference between R. japonica and other pathogenic SFG rickettsiae.     

枯草芽孢杆菌聚谷氨酸合成途径相关基因功能研究

聚谷氨酸(polyglutamic acid, PGA)作为一种天然多功能的聚合物,近年来成为研究的热点。由于很难通过化学方法合成,微生物发酵是目前生产聚谷氨酸的有效途径。【目的】从基因水平探究枯草芽孢杆菌聚谷氨酸合成途径中degS、degQ、degU、swrA、rocA、putM基因的功能,通过分子改造实现对代谢途径的调控。【方法】以枯草芽孢杆菌为出发菌株,通过对代谢途径中相关基因进行敲除或过表达,分别构建degS、degQ和degU基因缺失的重组菌,swrA、rocA和putM基因过表达的重组菌,借助菌株胞外聚谷氨酸积累的变化分析影响途径的关键节点。【结果】在摇瓶发酵条件下,重组菌Bacillus subtilis 168-swrA、Bacillus subtilis 168-rocA、Bacillus subtilis 168-putM的胞外聚谷氨酸含量分别是原始菌株的1.28倍、1.47倍和1.37倍。重组菌Bacillus subtilis 168-ΔdegS、Bacillus subtilis 168-ΔdegQ、Bacillus subtilis 168-ΔdegU的胞外...     

生物有机肥对菠萝心腐病及根际土壤细菌群落的影响

【目的】探明施用生物有机肥对菠萝心腐病的防控效果及对根际土壤微生物的影响。【方法】本研究采用高通量测序技术,综合分析不同施肥措施根际土壤微生物细菌群落多样性及群落特征。【结果】相比常规施肥处理(CK)和普通有机肥处理(YJ),生物有机肥处理KN (羊粪有机肥+泥炭土+枯草芽孢杆菌)和生物有机肥处理KY (羊粪有机肥+椰糠+枯草芽孢杆菌)均能显著降低菠萝心腐病的发病率,且KN处理的防控效果最佳。生物有机肥(KN、KY)施入后土壤细菌α多样性指数高于CK和YJ处理,并形成了明显不同的细菌群落结构。与CK相比,生物有机肥KN处理显著提高了拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)的丰度,KY处理中的酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)、芽单胞菌门(Gemmatimonadetes)、硝化螺旋菌门(Nitrospirae)丰度显著增加;属水平上,生物有机肥中的蔗糖伯克霍尔德菌属(Paraburkholderia)和黄杆菌属(Flavobacterium)丰度均显著提升。方差分区分析(variance partitioning analysis, VPA)表明,土壤化学性质(36.29%)对细菌群落影响最大,其中土壤速效钾和有机质是影响土壤细菌群落的关键因子,此外发病率(22.53%)和肥料偏生产力(16.42%)也是影响土壤细菌群落的重要因子。【结论】施用生物有机肥(KN、KY)能改变根际土壤细菌群落结构,降低发病率,对菠萝根际土壤生态系统稳定与健康具有重要意义。     

野芹菜体细胞胚胎发生早期变化的细胞学研究

通过光学与电子显微镜观察研究了野芹菜(Angelica polymorpha Maxim.)叶柄外植体胚性细胞的起源与原胚状体的发生。叶柄切段植入 MS 2mg/L2,4-D 0.25 mg/L KT固体培养基后,以DNA合成和细胞分裂为指标,判明了胚状体发生与紧贴维管束的鞘细胞层密切相关;鞘细胞通过有丝分裂形成多层结构的细胞群,它们仍含大液泡及薄层胞质,成片被覆在维管束表面;胚性细胞团即不同步地发生在该多层组织较内层的局部位点上,细胞具大核,胞质稠密,经持续有丝分裂发展成大小不同呈瘤状突起的原胚状体。伴随着鞘细胞的剧烈变化,韧皮部薄壁细胞亦分裂增殖,原有筛管变形衰退,部分新增殖的细胞分化为新筛分子;木质部中,原导管束附近朝向韧皮部一侧的部分薄壁细胞亦进一步分化为孔纹导管。外植体中维管系统的再次分化,显然是与输导功能强化以适应原胚状体发生时对营养物质的大量需求有关。     

The complex genome and adaptive evolution of polyploid Chinese pepper (Zanthoxylum armatum and Zanthoxylum bungeanum)

Zanthoxylum armatum and Zanthoxylum bungeanum, known as ‘Chinese pepper’, are distinguished by their extraordinary complex genomes, phenotypic innovation of adaptive evolution and species-special metabolites. Here, we report reference-grade genomes of Z. armatum and Z. bungeanum. Using high coverage sequence data and comprehensive assembly strategies, we derived 66 pseudochromosomes comprising 33 homologous phased groups of two subgenomes, including autotetraploid Z. armatum. The genomic rearrangements and two whole-genome duplications created large (~4.5 Gb) complex genomes with a high ratio of repetitive sequences (>82%) and high chromosome number (2n = 4x = 132). Further analysis of the high-quality genomes shed lights on the genomic basis of involutional reproduction, allomones biosynthesis and adaptive evolution in Chinese pepper, revealing a high consistent relationship between genomic evolution, environmental factors and phenotypic innovation. Our study provides genomic resources and new insights for investigating diversification and phenotypic innovation in Chinese pepper, with broader implications for the protection of plants under severe environmental changes.     

Upgrading the genome of an elite japonica rice variety Kongyu 131 for lodging resistance improvement

Developing a new rice variety requires tremendous efforts and years of input. To improve the defect traits of the excellent varieties becomes more cost and time efficient than breeding a completely new variety. Kongyu 131 is a high-performing japonica variety with early maturity, high yield, wide adaptability and cold resistance, but the poor-lodging resistance hinders the industrial production of Kongyu 131 in the Northeastern China. In this study, we attempted to improve the lodging resistance of Kongyu 131 from perspectives of both gene and trait. On the one hand, by QTL analysis and fine mapping we discovered the candidate gene loci. The following CRISPR/Cas9 and transgenic complementation study confirmed that Sd1 dominated the lodging resistance and favourable allele was mined for precise introduction and improvement. On the other hand, the Sd1 allelic variant was identified in Kongyu 131 by sequence alignment, then introduced another excellent allelic variation by backcrossing. Then, the two new resulting Kongyu 131 went through the field evaluation under different environments, planting densities and nitrogen fertilizer conditions. The results showed that the plant height of upgraded Kongyu 131 was 17%–26% lower than Kongyu 131 without penalty in yield. This study demonstrated a precise and targeted way to update the rice genome and upgrade the elite rice varieties by improving only a few gene defects from the perspective of breeding.     

GPD1L inhibits renal cell carcinoma progression by regulating PINK1/Parkin-mediated mitophagy

Few approaches have been conducted in the treatment of renal cell carcinoma (RCC) after nephrectomy, resulting in a high mortality rate in urological tumours. Mitophagy is a mechanism of mitochondrial quality control that enables selective degradation of damaged and unnecessary mitochondria. Previous studies have found that glycerol-3-phosphate dehydrogenase 1-like (GPD1L) is associated with the progression of tumours such as lung cancer, colorectal cancer and oropharyngeal cancer, but the potential mechanism in RCC is still unclear. In this study, microarrays from tumour databases were analysed. The expression of GPD1L was confirmed by RT–qPCR and western blotting. The effect and mechanism of GPD1L were explored using cell counting kit 8, wound healing, invasion, flow cytometry and mitophagy-related experiments. The role of GPD1L was further confirmed in vivo. The results showed that GPD1L expression was downregulated and positively correlated with prognosis in RCC. Functional experiments revealed that GPD1L prevented proliferation, migration and invasion while promoting apoptosis and mitochondrial injury in vitro. The mechanistic results indicated that GPD1L interacted with PINK1, promoting PINK1/Parkin-mediated mitophagy. However, inhibition of PINK1 reversed GPD1L-mediated mitochondrial injury and mitophagy. Moreover, GPD1L prevented tumour growth and promoted mitophagy by activating the PINK1/Parkin pathway in vivo. Our study shows that GPD1L has a positive correlation with the prognosis of RCC. The potential mechanism involves interacting with PINK1 and regulating the PINK1/Parkin pathway. In conclusion, these results reveal that GPD1L can act as a biomarker and target for RCC diagnosis and therapy.     

从城市到城市群：京津冀物质代谢特征及影响因素

随着城市化进程和一体化战略的持续推进,城市管理者急需了解城市规律以消减生态-资源-环境挑战,并提供坚实物质基础。以京津冀城市群及其组成城市为研究对象,创新性地从城市群和城市两尺度核算并分析了2000—2017年物质消耗状况及变化趋势,识别并对比了主要贡献物质、贡献部门和影响因素。研究表明：(1)研究期间,京津冀城市群物质消耗量总体上升。从物质类型看,主要由非金属矿物(>34.2%)拉动;从产业结构看,受到工业部门(>58%)绝对影响。首要驱动因素为经济规模(>50%)。(2)各城市物质消耗量与城市群较为类似,总体也呈增长态势,几乎均受到非金属矿物和工业部门驱动,且经济规模起到正向促进作用,不同的是物质消耗强度作用类型多样,且产业结构效应在城市中贡献更为突出。研究结果在一定程度上明确了城市及城市群代谢的规律,能够为优化资源利用效率和资源配置结构奠定基础,为城市及城市群生态管理与调控提供切实可行的落力点。