不同寄主对草地贪夜蛾生长发育和繁殖的影响

草地贪夜蛾是入侵我国的重大农业害虫,严重威胁我国粮食安全。为明确该虫在不同寄主植物上的适合度,本文系统研究了草地贪夜蛾取食花生、荞麦和生姜3种寄主生长发育和繁殖情况,组建了实验种群生命表。结果表明:草地贪夜蛾在3种寄主植物上的繁殖力高低为花生(771.73粒)>荞麦(477.13粒)>生姜(209.22粒),卵的孵化率无显著差异,幼虫和蛹重均是花生>荞麦>生姜。草地贪夜蛾取食花生、荞麦和生姜后的净增殖率(R 0)分别为226.36、102.45和20.75,内禀增长率(r m)分别为0.16、0.13和0.06。研究发现,草地贪夜蛾在花生、荞麦和生姜3种寄主植物上均能实现种群繁殖,其中,花生是最适宜的寄主,荞麦次之,生姜相对较不适宜。     

Structural and sequence comparisons of bacterial enoyl-CoA isomerase and enoyl-CoA hydratase

Crystal structures of enoyl-coenzyme A (CoA) isomerase from Bosea sp. PAMC 26642 (BoECI) and enoyl-CoA hydratase from Hymenobacter sp. PAMC 26628 (HyECH) were determined at 2.35 and 2.70 Å resolution, respectively. BoECI and HyECH are members of the crotonase superfamily and are enzymes known to be involved in fatty acid degradation. Structurally, these enzymes are highly similar except for the orientation of their C-terminal helix domain. Analytical ultracentrifugation was performed to determine the oligomerization states of BoECI and HyECH revealing they exist as trimers in solution. However, their putative ligand-binding sites and active site residue compositions are dissimilar. Comparative sequence and structural analysis revealed that the active site of BoECI had one glutamate residue (Glu135), this site is occupied by an aspartate in some ECIs, and the active sites of HyECH had two highly conserved glutamate residues (Glu118 and Glu138). Moreover, HyECH possesses a salt bridge interaction between Glu98 and Arg152 near the active site. This interaction may allow the catalytic Glu118 residue to have a specific conformation for the ECH enzyme reaction. This salt bridge interaction is highly conserved in known bacterial ECH structures and ECI enzymes do not have this type of interaction. Collectively, our comparative sequential and structural studies have provided useful information to distinguish and classify two similar bacterial crotonase superfamily enzymes.     

Sequence analysis of the first B5 subgenogroup strain of enterovirus 71 isolated in Korea

Journal of Microbiology - Enterovirus A71 (EV71), the main etiological agent of handfoot- mouth disease (HFMD), circulates in many areas of the world and has caused large epidemics since 1997,...     

Practical methodology for gametophyte proliferation and sporophyte production in green penny fern (Lemmaphyllum microphyllum C. Presl) using mechanical fragmentation

Propagation of gametophytes and sporophytes using mechanical fragmentation has been considered a suitable method for mass production of ferns. This study aimed to develop a practical propagation method for Lemmaphyllum microphyllum C. Presl, which is a fern of significant ornamental and medicinal value. Gametophytes were obtained through in vitro spore germination and used for propagation experiments. The gametophyte was mechanically fragmented using a scalpel into small fragments, which were then used to investigate gametophyte proliferation. In addition, the gametophyte was fragmented using a blender and then used to study sporophyte formation. Optimal proliferation conditions of the gametophyte were determined using Murashige and Skoog (MS) basal medium (double-, full-, half-, quarter-strength), Knop medium, and medium components (sucrose, nitrogen sources, activated charcoal), at various concentrations. The fresh weight of the gametophyte was 14-fold higher than that of gametophytes (300 mg) used as culture material, when cultured on double-strength MS. Moreover, 1 g of the gametophyte fragmented in 25 mL of distilled water formed more than 430 sporophytes in a soil mixture in an area of 7.5 cm². The sporophytes were successfully cultivated in the greenhouse after acclimation. A large-scale production method for L. microphyllum that can be easily implemented in a fern production farm is outlined.

     

一种紫斑牡丹花茶的研制及其主要香气成分分析

以紫斑牡丹(Paeonia suffruticosa var. papaveracea)花瓣为原料,采用隔离窨制,对牡丹花茶窨制过程中花坯、配花量等主要影响因子进行研究。结果表明,密闭箱桶温度21 ℃、相对湿度90%、窨制时间48 h条件下经一窨一提获得的花茶,感官评审花与茶叶的协调度高、香气高锐持久、茶汤滋味醇正鲜爽。采用气相色谱-质谱联用仪分析花茶香气成分,新鲜花瓣与茶叶配比5:1窨制48 h的花茶苯乙醇、香叶醇、橙花醇含量较高,其香气高扬、茶汤醇正鲜爽,配比2.5:1的花茶上述成分含量和感官其次,而拌和型茶品透素欠鲜爽。发酵或发酵揉捻花瓣窨制的花茶乙醇、环氧芳樟醇及高级烷烃含量较高,其主要赋香物质低于新鲜花瓣含量,渥味明显,茶汤有浊气欠鲜爽。     

Insight into the bovine milk peptide LPcin‐YK3 selection in the proteolytic system of Lactobacillus species

Antimicrobial peptides are class of small, positively charged peptides known for their broad‐spectrum antimicrobial activity. Antimicrobial activities for most antimicrobial peptides have largely remained elusive, particularly in the lactic acid bacteria. However, recently our investigation using LPcin‐YK3, an antimicrobial peptide from bovine milk, suggests that in vitro antimicrobial activity was reduced over 100‐fold compared with pathogenic bacteria. Additionally, for the structural study of how antimicrobial peptide undergoes its reaction at the proteolytic pathway of lactic acid bacteria based on degradation assay and propidium iodide staining, we performed molecular docking for interaction between oligopeptide‐binding protein A and LPcin‐YK3 peptide. Given that degradation related to the LPcin‐YK3 peptide in lactic acid bacteria proteolytic system, the inhibitory inactivity of LPcin‐YK3 against beneficial lactic acid bacteria strains may be one of the primary pharmacological properties of recombinant peptide discovered in bovine milk. These results provide structural and functional insights into the proteolytic mechanism and possibility as a putative substrate of oligopeptide‐binding protein A in respect of LPcin‐YK3 peptide.     

A chromosome‐level genome assembly reveals the genetic basis of cold tolerance in a notorious rice insect pest,Chilo suppressalis

The rice stem borer, Chilo suppressalis, is one of the most damaging insect pests to rice production worldwide. Although C. suppressalis has been the focus of numerous studies examining cold tolerance and diapause, plant–insect interactions, pesticide targets and resistance, and the development of RNAi‐mediated pest management, the absence of a high‐quality genome has limited deeper insights. To address this limitation, we generated a draft C. suppressalis genome constructed from both Illumina and PacBio sequences. The assembled genome size was 824.35 Mb with a contig N₅₀ of 307 kb and a scaffold N₅₀ of 1.75 Mb. Hi‐C scaffolding assigned 99.2% of the bases to one of 29 chromosomes. Based on universal single‐copy orthologues (BUSCO), the draft genome assembly was estimated to be 97% complete and is predicted to encompass 15,653 protein‐coding genes. Cold tolerance is an extreme survival strategy found in animals. However, little is known regarding the genetic basis of the winter ecology of C. suppressalis. Here, we focused our orthologous analysis on those gene families associated with animal cold tolerance. Our finding provided the first genomic evidence revealing specific cold‐tolerant strategies in C. suppressalis, including those involved in glucose‐originated glycerol biosynthesis, triacylglycerol‐originated glycerol biosynthesis, fatty acid synthesis and trehalose transport‐intermediate cold tolerance. The high‐quality C. suppressalis genome provides a valuable resource for research into a broad range of areas in molecular ecology, and subsequently benefits developing modern pest control strategies.