草莓白化相关病毒中国分离物全基因组分析

草莓白化相关病毒(strawberrypallidosis-associatedvirus,SPa V)属于长线形病毒科(Closteroviridae)毛形病毒属(Crinivirus),可引起草莓病害,2017年在中国首次报道。采用高通量测序、RACE和RT-PCR技术获得了SPa V中国分离物(FJ)的基因组全长。该病毒含有两条正单链基因组RNA1和RNA2。RNA1全长8 048 nt,5′和3′非编码区序列分别为264和197 nt,含有3个开放阅读框(ORF),分别编码ORF 1a/1b融合蛋白和p9蛋白。RNA2全长7 977 nt,5′和3′非编码区序列分别为248和186 nt,含有8个开放阅读框(ORF),分别编码HSP70h、CPh、CP、CPm、p7、p6、p9和p28等8个蛋白。RNA1和RNA2与美国M1分离物分别具有98.5%和99.0%的核苷酸一致性;系统发育分析结果表明,SPa V中国分离物(FJ)单独处在一个分支。对SPa V来源的小RNA的分析表明,来源于SPa V的小RAN长度以21和22 nt为主。     

甲壳素对连作平邑甜茶生长、光合及抗氧化酶的影响

以苹果连作土盆栽的平邑甜茶幼苗为试材,探讨了0、0.5、1.0和2.5 g·kg-1不同施入量的甲壳素对其光合速率、活性氧含量及抗氧化酶活性的影响。结果表明,1.0 g·kg-1的甲壳素处理能显著促进幼苗株高、地径,干样质量和根冠比的增加,根冠比为对照的1.51倍;明显提高了幼苗叶片光合色素含量、净光合速率和蒸腾速率,其中光合速率为对照的1.30倍;同时提高了幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性,分别为对照的1.10倍、1.85倍、1.77倍和1.43倍;减少了叶片丙二醛(MDA)、过氧化氢(H2O2)和超氧阴离子的积累,分别为对照的73%、62%和34%,降低了脯氨酸(Pro)和可溶性糖含量。当甲壳素施用量为2.5 g·kg-1时则显著抑制平邑甜茶幼苗生长,降低幼苗叶片光合速率和抗氧化酶活性,并使超氧阴离子和脯氨酸含量明显上升。因此,适宜用量的甲壳素能减轻苹果的连作障碍。     

贺兰山野生大型真菌孢子多样性分析

为探讨贺兰山野生大型真菌孢子的多样性,2012-2016年在内蒙古贺兰山南寺和哈拉乌沟两地进行取样,每个样地分别由5人从沟谷入口处进行拉网式调查,共获得4 000余份样品,经过微观形态观察和基因ITS序列比对,鉴定出8目25科69属189种大型真菌,主要对其孢子形态特征、表面特征及长宽比进行分析,得到如下结论:质量性状上,孢子形态特征和表面特征相互独立;数量性状上,大小孢子长宽比、孢子极端比和平均比均具有一致性和关联性,显示孢子数量特征的稳定性;菌种间孢子质量性状和数量性状具有很强的多样性;按照孢子多样性低、中、高分类,贺兰山野生大型真菌物种数分别为152种、26种和11种;孢子多样性分类为大型真菌鉴别、分类提供了基本依据。     

A new species of Malus in China,Malus shizongensis Liu sp. nov

Based on morphological, molecular biological, and molecular systematic studies, we describe here a new species of Malus from Yunnan, China. We compared the morphology of this new species, Malus shizongensis Liu sp. nov, with three Malus species, including M. hupehensis, M. baccata, and M. micromalus. Although the appearance of M. shizongensis was similar to these three species, it differed in height, branch color, branch hair, and flower color. To better identify the taxonomy of this new species, genome of M. shizongensis and that of seven Malus species, including M. prunifolia, M. sylvestris, M. sieversii, M. hupehensis, M. baccata, M. robusta, and M. micromalus were analyzed. A phylogenetic tree based on genome analysis indicated that M. shizongensis was close to M. hupehensis. Furthermore, M. shizongensis had its species-specific SNPs, and the number of species-specific SNPs was similar to that of three close species(M. hupehensis, M. baccata, and M. micromalus). Based on the above information, we named this new species as M. shizongensis Liu sp. nov.     

Mycoplasma pneumoniae induces IL-1β production through activating NLRP3 inflammasome by ROS in RAW264.7 cells

AIM: To investigate whether Mycoplasma pneumoniae (Mp)-induced interleukin-1β (IL-1β) production in RAW264.7 cells is through the activation of NLRP3 inflammasome via reactive oxygen species (ROS). ME-THODS: RAW264.7 cells were randomly divided into 3 groups. In normal group, RAW264.7 cells were treated without Mp. In model group, RAW264.7 cells were treated with 1∶ 10 multiplicity of infection (MOI) of Mp. In NAC group, RAW264.7 cells were pretreated with N- acetylcysteine (NAC) at a concentration of 5 mmol/L for 30 min before infection with Mp. The RAW264.7cells were infected with Mp (1∶ 10 MOI) for 4, 8, 16 and 24 h in model group and NAC group, respectively. The intracellular ROS level was analyzed by flow cytometry. The mRNA expressions of NLRP3, ASC and caspase-1 were detected by real-time PCR. The protein levels of NLRP3, ASC and caspase-1 p20 were determined by Western blot. The levels of pro-inflammatory cytokine IL-1β in the supernatant were measured by ELISA. RESULTS: Compared with normal group, the production of ROS were significantly increased at 4, 8, 16 and 24 h after infection, the mRNA expression of NLRP3, ASC and caspase-1 were increased at 8, 16 and 24 h after infection, the protein levels of NLRP3, ASC and caspase-1 p20 were increased at 16 and 24 h after infection, and the releases of IL-1β were increased at 24 h after infection in model group (P<0.01). Compared with the model group, the level of ROS in NAC group decreased, so as the expression of NLRP3, ASC and caspase-1 at mRNA and protein levels and the releases of IL-1β in the supernatant at the corresponding time points. CONCLUSION: Mp may stimulate the ROS production to activate NLRP3 inflammasome in RAW264.7 cells.     

极小种群野生植物八蕊单室茱萸的种群状况研究

八蕊单室茱萸为云南省特有的极小种群野生植物和濒危物种。通过查阅相关文献并结合访问调查,确定八蕊单室茱萸可能分布的区域,开展种群资源调查。结果显示:八蕊单室茱萸目前仅在普洱市和西双版纳州有10个天然种群,其种群规模已低于最小可存活种群,属极小种群野生植物和濒危物种,亟需开展保护工作。生境破坏和生境片段化是导致八蕊单室茱单室茱萸濒危的人为因素。提出收集种质资源、营建和管护近地保护种群、建立迁地和回归种群等保育建议。     

Cultivar Specific Response of CO2 Fertilization on Two Tropical Mung Bean (Vigna radiata L.) Cultivars: ROS Generation,Antioxidant Status,Physiology, Growth,Yield and Seed Quality

Increasing atmospheric carbon dioxide concentration (CO₂) is an important component of global climate change that will have a significant impact on the productivity of crop plants. In recent years, growth and yield of agricultural crop plants have been shown to increase with elevated CO₂ (EC) and have enticed considerable interest due to variation in the response of crop plants. In this study, comparative response of two mung bean cultivars (HUM‐2 and HUM‐6) was evaluated against EC at different growth stages under near‐natural conditions for two consecutive years. The plants were grown in ambient as well as EC (700 ppm) in specially designed open‐top chambers. Under elevated CO₂, marked down‐regulation of reactive oxygen species (ROS) levels, membrane disruption and activities of superoxide dismutase and catalase were noticed in both the cultivars, but the extent of reduction was more in HUM‐6. As compared to ambient CO₂, EC increased total chlorophyll, photosynthetic rate, growth and yield parameters. Cultivar‐specific response was noticed as HUM‐6 showed higher increase in yield attributes than HUM‐2. Under CO₂ treatment, soluble protein and reducing sugars decreased while total soluble sugars and starch showed an opposite trend. Principal component analysis showed that both the cultivars responded more or less similarly to EC in their respective groupings of physiological and growth parameters, but the magnitude of ROS and antioxidative enzymes was variable. The experimental findings depict that both the cultivars of mung bean showed contrasting response against EC and paved the way for selecting the suitable cultivar having higher productivity in a future high‐CO₂ environment.     

灰霉菌侵染对番茄幼苗活性氧积累及抗氧化酶活性的影响

为进一步分析活性氧和抗氧化防御系统在番茄抗病信号调控机制中的作用,为提高产量和品质提供科学依据,以4叶1心的番茄幼苗为试验材料,比较番茄幼苗受灰霉菌侵染后叶片O_2~-·以及抗氧化酶、内源褪黑素等的变化。结果表明:番茄幼苗接种灰霉菌后,随着时间的延长,幼苗叶片上病斑斑点逐渐增多,灰霉菌含量显著增多,叶色逐渐变浅,植株表现明显的发病症状;灰霉病菌侵染后番茄体内O_2~-·活性爆发,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性下降,过氧化氢酶(CAT)和谷胱甘肽还原酶(GR)活性上升,褪黑素含量增加;上述变化都是番茄幼苗为了抵御灰霉菌的生物胁迫而发生的应激反应。综上,植物在遭受病原菌等生物胁迫时不能简单地推断SOD、CAT和POD等抗氧化酶活性一定升高,植物抵御病原菌侵染更多地依赖于抗性信号路径中信号物质的激活和积累。     

Relationship of Icelandic cattle with Northern and Western European cattle breeds,admixture and population structure

ABSTRACT

Icelandic cattle is believed to have been brought from Norway during the settlement of Iceland around AD 870-930. Previous research on genetic relationships has indicated that Icelandic cattle is most related to northern Nordic indigenous breeds. Using single nucleotide polymorphism genotype data from Icelandic cattle and 29 Northern and Western European cattle breeds, we studied relationships and admixture among these breeds, and assessed population structure in Icelandic cattle. Population structure analysis through principal component analysis, estimation of ancestry, and analysis of patterns of population splitting and mixing revealed that Icelandic cattle are most related to three Finncattle breeds (Eastern, Northern and Western Finncattle), and Swedish Mountain cattle. Icelandic cattle has very low levels of admixture. We observed very limited population structure in Icelandic cattle. The observed structure was due to variable sire contributions. Over 1000 years of almost complete isolation has made Icelandic cattle highly genetically distinct from other cattle breeds.