First record of organic-walled microfossils from the Tonian Shiwangzhuang Formation of the Tumen Group in western Shandong,North China

Organic-walled microfossils offer important information on the biospheric evolution in pre-Cryogenian and provide biostratigraphic implications for many Proterozoic fossiliferous sequences that are poorly age constrained for the lack of reliable radiometric date. Recently, macroscopic carbonaceous compression fossils have been reported for the first time from the Tonian Shiwangzhuang Formation of the Tumen Group in western Shandong, North China. However, organic-walled microfossils have never been discovered from this formation up till now. To improve our knowledge about Proterozoic biodiversity in North China, we conducted a micropaleontological survey on the argillaceous limestone samples of the Shiwangzhuang Formation, which also contain macroscopic carbonaceous compression fossils, from the Baishicun section in Anqiu, western Shandong, North China. Our investigation shows that the Shiwangzhuang microfossil assemblage is dominated by smooth-walled sphaeromorphic acritarchs and cyanobacterium-like filaments and relatively low abundance of other acritarchs, including 16 taxa, such as Polysphaeroides filliformis, Ostiana microcystis, Simia annulare, ?Jacutianema sp., Arctacellularia tetragonala, Pellicularia tenera, Polythrichoides lineatus, and Navifusa actinomorpha. The Shiwangzhuang organic-walled microfossil assemblage, although consisting of long-ranging and not age diagnostic taxa, is consistent with a Tonian age suggested by macroscopic carbonaceous compression fossils, including the Chuaria-Tawuia and Sinosabellidites-Protoarenicola-Pararenicola assemblages, revealed from the same fossiliferous horizon of the Shiwangzhuang Formation and by organic-walled microfossil assemblage, including the late Mesoproterozoic to Tonian index fossil Trachyhystrichosphaera aimika, from the underlying Tongjiazhuang Formation. However, it is also worth noting that a Cryogenian or Ediacaran age cannot be completely excluded based just on the Shiwangzhuang microfossils because of their limited biostratigraphic utility.     

吉林珲春电子围栏防控野猪危害农田的效果研究

近年来,随着野猪（Sus scrofa）数量不断增长,人与野猪之间的冲突也随之增加。2021年8至10月,在吉林省珲春市春化镇开展了电子围栏防控野猪危害农田的效果研究。研究共布设40块样地,以单次脉冲强度与栏线圈数来区分电子围栏,以防控有效期长度、进入样地野猪数量与农作物损失率衡量防控的有效性。研究结果如下：（1）电子围栏对野猪危害农田的防控效果显著,所有实验组的防控有效期长度、进入样地野猪数量、农作物损失率均与对照组存在显著差异（P <0.05）。（2）电子围栏的脉冲强度对野猪危害农田的防控效果影响不显著。电子围栏的栏线圈数为2,脉冲强度分别为0.3 J、1.0 J和2.0 J的样地中,防控有效期长度、进入样地的野猪数量、农作物损失率均无显著差异（P> 0.05）。（3）电子围栏的栏线圈数不同组别,防控效果不同。3圈栏线的电子围栏组防控有效期为（29.2±1.4）d,进入样地野猪数量为（0.7±1.0）ind,农作物损失率为4.28%±8.24%;2圈栏线的电子围栏组防控有效期为（27.3±3.3）d,进入样地野猪数量为（1.0±1.3）ind,农作物损失率为7.98%±...     

Quantitative analysis of pyoluteorin in anti-fungal fermentation liquor of Pseudomonas species by capillary zone electrophoresis with UV-vis detector

This paper investigated potential utility of capillary zone electrophoresis (CZE) for very succinct but robust quantitative analysis of pyoluteorin (Plt) in anti-fungal fermentation liquor of Pseudomonas species. The experimental conditions for the separation and quantification of Plt were optimized at first. The optimized conditions are: 80 mmol/L pH 8.40 Gly-NaOH buffer, 51 cm total length (42 cm effective) and 75 microm I.D. capillary, 230 nm wavelength, 25 kV, 13 mbar 10s pressure sample injection and 24 degrees C air-cooling. Under the optimized conditions, the migration times of Plt and the internal standard phenobarbital are 2.09 and 2.49 min, respectively, the linear response of Plt concentration ranges from 5.0 to 1000 microg/mL with high correlation coefficient (r=0.99977, n=9), the limits of detection (LOD) and quantification (LOQ) for Plt are 0.66 and 2.2 microg/mL, the precision values (expressed as R.S.D.) of intra- and inter-day are 1.19-1.94% and 1.55-6.21%, respectively, the recoveries of Plt at three concentration levels of 750, 250 and 50 microg/mL range from 90.31% to 97.85% and to 98.96%, respectively. The developed method can be well used for the quantification of Plt in the fermentation liquor.     

绥农14及其系谱亲本的遗传多样性及重组分析

以绥农14及其系谱中的亲本品种为实验材料, 对14个农艺性状及分布在20个大豆连锁群上139对SSR引物进行分析, 揭示品种间遗传多样性和遗传重组关系, 为大豆新品种选育提供理论依据。聚类分析结果与品种间的亲缘关系相似, 每个SSR位点Shannon-Weaver指数的分布范围为0~1.677; 品种间的相似系数平均值为0.6380, 变化范围为0.5380~0.7990。筛选出区分这些品种的最少SSR位点数为3个; 如Satt543、Sat_130、Satt218。研究发现, 连锁群中间区段重组率与两个末端区段重组率无显著性差异, 说明连锁群上各区段的遗传重组是随机分布的。在139对引物中有39对引物在绥农14及其8个亲本间没有多态性, 表明这些位点可能对品种改良具有重要作用; 位于B2连锁群的Satt168是从祖先亲本紫花4号保留给绥农14的唯一的多态性位点, 可见, 经过5个世代的杂交重组和遗传改良, 绥农14的遗传组成与紫花4号相比已经发生了很大的变化。     

Hydrogen sulfide protects soybean seedlings against drought-induced oxidative stress

Increasing evidence indicates that hydrogen sulfide (H₂S) is the third “gas signal molecule” after NO and CO in animal. In the present study, we found that soybean (Glycine max L.) seedlings sprayed with exogenous H₂S donor NaHS prolonged the longer survival time of life, and enlarged higher biomass of both leaf and root than in non-sprayed controls under continuous drought stress. With the continuous drought stress, the content of chlorophyll in the leaves of both Xu-1 and Xu-6 cultivar of soybean decreased dramatically. The drought-induced decrease in chlorophyll could be alleviated by spraying H₂S donor. It was also shown that spraying with H₂S donor dramatically retained higher activities of superoxide dismutase (SOD, EC 1.1.5.1.1), catalase (CAT, EC1.11.1.6) and lower activity of lipoxygenases (LOX, EC 1.13.11.12), delayed excessive accumulation of malondialdehyde, hydrogen peroxide, and superoxide anion (O₂^·−) compared with the control. These results suggest that H₂S can increase drought tolerance in soybean seedlings by acting as an antioxidant signal molecule for the response.     

Subcellular localization and identification of acyl-CoA: lysophosphatidylethanolamine acyltransferase (LPEAT) in the arachidonic acid-rich green microalga,Myrmecia incisa Reisigl

Journal of Applied Phycology - Lysophosphatidylethanolamine acyltransferase (LPEAT) plays an important role in acyl remodeling of phospholipid via the Lands’ cycle, and consequently alters...     

Reference-Free Comparative Genomics of 174 Chloroplasts

Direct analysis of unassembled genomic data could greatly increase the power of short read DNA sequencing technologies and allow comparative genomics of organisms without a completed reference available. Here, we compare 174 chloroplasts by analyzing the taxanomic distribution of short kmers across genomes [1]. We then assemble de novo contigs centered on informative variation. The localized de novo contigs can be separated into two major classes: tip = unique to a single genome and group = shared by a subset of genomes. Prior to assembly, we found that ∼18% of the chloroplast was duplicated in the inverted repeat (IR) region across a four-fold difference in genome sizes, from a highly reduced parasitic orchid [2] to a massive algal chloroplast [3], including gnetophytes [4] and cycads [5]. The conservation of this ratio between single copy and duplicated sequence was basal among green plants, independent of photosynthesis and mechanism of genome size change, and different in gymnosperms and lower plants. Major lineages in the angiosperm clade differed in the pattern of shared kmers and de novo contigs. For example, parasitic plants demonstrated an expected accelerated overall rate of evolution, while the hemi-parasitic genomes contained a great deal more novel sequence than holo-parasitic plants, suggesting different mechanisms at different stages of genomic contraction. Additionally, the legumes are diverging more quickly and in different ways than other major families. Small duplicated fragments of the rrn23 genes were deeply conserved among seed plants, including among several species without the IR regions, indicating a crucial functional role of this duplication. Localized de novo assembly of informative kmers greatly reduces the complexity of large comparative analyses by confining the analysis to a small partition of data and genomes relevant to the specific question, allowing direct analysis of next-gen sequence data from previously unstudied genomes and rapid discovery of informative candidate regions.