Diverse flowering responses subjecting to ambient high temperature in soybean under short-day conditions

Flowering time is one of important agronomic traits determining the crop yield and affected by high temperature. When facing high ambient temperature, plants often initiate early flowering as an adaptive strategy to escape the stress and ensure successful reproduction. However, here we find opposing ways in the short-day crop soybean to respond to different levels of high temperatures, in which flowering accelerates when temperature changes from 25 to 30 °C, but delays when temperature reaches 35 °C under short day. phyA-E1, possibly photoperiodic pathway, is crucial for 35 °C-mediated late flowering, however, does not contribute to promoting flowering at 30 °C. 30 °C-induced up-regulation of FT2a and FT5a leads to early flowering, independent of E1. Therefore, distinct responsive mechanisms are adopted by soybean when facing different levels of high temperatures for successful flowering and reproduction.     

来源于嗜热氢化杆菌的新型对苯二甲酸双(羟乙)酯水解酶的表达纯化与酶学性质

石化来源的聚对苯二甲酸乙二酯(polyethylene terephthalate,PET)被广泛用于矿泉水瓶、食品包装和纺织品等领域,因其在自然界中不易分解,大量使用后的PET废弃物造成了严重的环境污染与资源浪费。使用生物酶法对PET废弃物进行解聚,并对解聚产物进行升级循环利用是进行塑料污染治理的重要方向之一,其中关键的是PET水解酶的解聚效率。对苯二甲酸双(羟乙基)酯(bis(hydroxyethyl)terephthalate,BHET)是PET生物酶解的中间产物,其累积是限制PET水解酶催化效率的一个重要因素,BHET水解酶和PET水解酶的联用能提升PET的整体水解效率。来源于嗜热氢化杆菌(Hydrogenobacter thermophilus)的双烯内酯酶(HtBHETase)对BHET有显著水解效果,将该酶在大肠杆菌(Escherichia coli)中进行重组表达并纯化后,对其酶学性质进行了研究。结果显示,HtBHETase对短碳链的酯类如对硝基苯酚乙酸酯催化活性较高,HtBHETase以BHET为底物时的最适反应pH值和最适反应温度分别为5.0和55℃;该酶有较好的热稳定性,经80℃的条件处理1 h仍能保持80%以上活性,显示出了良好的热稳定性,HtBHETase有在PET塑料生物解聚中使用的潜力,本研究为推动生物酶法降解PET提供了新的参考。     

Molecular mimicry in Lyme disease: monoclonal antibody H9724 to b. burgdorferi flagellin specifically detects chaperonin-HSP60

A monoclonal antibody (H9724), specific for the 41-kDa flagellar protein of the Lyme disease pathogen Borrelia burgdorferi, cross-reacts with human axons and detects one major protein in human neuroblastoma cell extracts. The homologous cross-reacting protein has now been isolated from calf adrenal and identified as chaperonin-HSP60 by N-terminal sequencing.     

色氨酸阻遏物与其操纵基因复合物的圆二色性研究

用圆二色性谱来确定色氨酸阻遏物与其操纵基因复合物在溶液中的构象变化。色氨酸阻遏物的圆二色性图谱表明它是一种富含α螺旋的蛋白质,通过比较加入Ｌ－Ｔｒｐ前和后的圆二色性谱,发现活性的与非活性的色酸阻遏物二级结构变化很小,ｔｒｐ Ｐ／Ｏ的圆二色性谱与它的单健、双链理论计算曲线对比,可近拟推测操纵基因在溶液中的存在状态。用色氨酸阻遏物对ｔｒｐ Ｐ／Ｏ进行确定,可以从中找出蛋白质与核酸结合的平衡点。从平衡时     

用胆固醇代谢的房室模型速率系数来分析动脉粥样硬化程度

理论上认为胆固醇逆向转运的速率与动脉粥样硬化程序呈负相关。但目前尚无完善的测试血浆脂蛋白－胆固醇体内代谢的方法。我们运用同位素＾３Ｈ－胆固醇示踪方法,建立房室模型,选取健康兔与ＡＳ兔对照,研究血浆脂蛋白转运胆固醇能力的差异,并结合ＡＳ兔主动脉斑块程度对比,结果验证了上述理论,此法如改用短半衰期同位素或稳定性同位素标记的胆固醇,就可用于人体,这可为临床判断ＡＳ程度提供一种无创性的新方法。     

稻根象甲种群空间格局及其受耕法的影响

本文根据36块田的调查,用种群空间格局参数I、C_A、I_δ、m~*/m和α、β值进行分析,稻根象甲幼虫和(?)≥0.6头/样方(每样方为0.5m~2)的成虫种群,在稻田均属具公共k值的负二项分布;(?)<0.6头/样方的成虫种群则为随机分布。成虫聚块的大小和面积与平均密度有关。低密度时种群的聚集主要由于环境的异质性;高密度时种群的聚集则由本身的行为习性所致。随着耕作强度的增加,幼虫种群的聚集度和越冬死亡率增大。     

平截独活的香豆素成分

从四川省汶川县产平截独活Heracleum vicinum根的乙醇提取物中分离鉴定了6个成分,分别为虎耳草素(pimpinellin)(1),异佛手柑内酯(2),6-甲氧基当归素(sphondin)(3)。佛手柑内酯(bergapten)(4),异虎耳草素(isopimpincllin)(5),falcarindi01)(6).     

中国扁裸藻属新记录

本文报道采自哈尔滨的扁裸藻属我国新记录3种2变种,它们是Phacus balatonicus var.boglariensis Hortob.,Ph.elegans Pochm.,Ph.glaber(Defl.)Pochm.,Ph.suecicus var.invermis Nyg.,Ph.war-szewiczii Drez.     

Environmentally-Friendly Pesticidal Activities of Callicarpa and Karomia Essential Oils from Vietnam and Their Microemulsions

There is an ongoing interest to identify alternative pesticidal agents to avoid the chronic problems associated with synthetic pesticides. Essential oils have shown promise as botanical pest control agents. In the present study, the essential oils of four members of the Lamiaceae (Callicarpa candicans, C. erioclona, C. macrophylla, and Karomia fragrans; Vietnamese names: Nàng nàng, Tu châu lông mem, Tu châu lá to and Cà diện, respectively), obtained from wild populations in Vietnam, have been obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The essential oils were formulated into microemulsions and the essential oils and their microemulsions were screened for mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and for molluscicidal activity against Pomacea canaliculata. Atractylone and (E)-caryophyllene dominated the volatiles of C. candicans (CCEO) and C. erioclona (CEEO), while the major component in C. macrophylla (CMEO) and K. fragrans (KFEO) was (E)-caryophyllene. The essential oils and microemulsions of both C. candicans and C. erioclona exhibited excellent larvicidal activity against all three mosquito species (Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus) with LC₅₀ values <10 μg/mL. Additionally, the larvicidal activity of the microemulsions were significantly improved compared with their free essential oils, especially for C. candicans and C. erioclona. All four essential oils and their microemulsions showed excellent molluscicidal activity with LC₅₀ <10 μg/mL. In most cases, the essential oils and microemulsions showed greater pesticidal activity against target organisms than the non-target freshwater fish, Oreochromis niloticus. The in silico studies on physicochemical and ADMET properties of the major components in the studied essential oils were also investigated and most of the compounds possessed a favorable ADMET profile. Computational modeling studies of the studied compounds demonstrated a favorable binding interaction with the mosquito odorant-binding protein target and support atractylone, β-selinene, and caryophyllene oxide as potential inhibitors. Based on the observed pesticidal activities of the essential oils and their microemulsions, the Callicarpa species and K. fragrans should be considered for potential cultivation and further exploration as botanical pesticidal agents.