Two serine protease inhibitors from the skin secretions of the toad, Bombina microdeladigitora

Two serine protease inhibitors (named BMSI 1 and BMSI 2, respectively) were identified from the skin secretions of the toad, Bombina microdeladigitora. The cDNAs encoding BMSIs were cloned from a cDNA library prepared from the toad skin. The deduced complete amino acid sequences of BMSIs indicate that mature BMSI 1 and BMSI 2 are composed of 60 amino acids including 10 half-cystines to form 5 disulfide bridges. A FASTA search in the databanks revealed that BMSIs exhibit sequence similarity with other serine protease inhibitors from amphibians of the genus Bombina. BMSI 1 potently inhibited trypsin and thrombin with a K(i) value of 0.02 μM and 0.15 μM, respectively. Sequence analysis revealed that all serine protease inhibitors from five amphibians of the genus Bombina share highly conserved primary structures.     

植物替代控制3种入侵杂草技术的研究与应用进展

植物替代控制是利用一种或多种植物的生长优势控制入侵杂草的方法,它是控制外来杂草危害的有效途径之一;因其既可控制入侵杂草危害又能取得一定的经济效益及生态效益而被人们广泛接受。本文简要介绍了我国3种入侵杂草植物替代控制技术研究与应用现状,系统总结了植物替代控制技术阻截和修复豚草、紫茎泽兰及黄顶菊扩散危害的技术模式和效果,提出了植物替代控制技术未来研究的方向和重点。     

不同施肥条件下旱田养分淋溶规律实验研究

从当今世界范围看 ,每年转入陆地生态系统中的总Ｎ量约为 2× 10 8ｔ。其中来自工业肥料的Ｎ含量占 2 0 %。目前全世界的施肥量仍在增加 ,发展中国家的增加速率比发达国家高得多。目前 ,我国的大部分耕地都需要补充Ｎ素 ,一半以上的耕地需要补充磷肥 ,大约 1/3～ 1/4以上的耕地需要补充钾肥。然而 ,由于种种原因 ,我国农田土壤养分的利用率一直较低 ,损失率较大。旱地土壤Ｎ素 (尿素 )利用率仅为 2 0 %～ 4 0 %。Ｐ的利用率 15 %～ 30 %。这一方面提高了农产品的成本 ,另一方面 ,过多的使用肥料又造成了环境问题[1,2 ] 。其中 ,一部分养分沿…     

Bcl-3 promotes TNF-induced hepatocyte apoptosis by regulating the deubiquitination of RIP1

Tumor necrosis factor-α (TNF) is described as a main regulator of cell survival and apoptosis in multiple types of cells, including hepatocytes. Dysregulation in TNF-induced apoptosis is associated with many autoimmune diseases and various liver diseases. Here, we demonstrated a crucial role of Bcl-3, an IκB family member, in regulating TNF-induced hepatic cell death. Specifically, we found that the presence of Bcl-3 promoted TNF-induced cell death in the liver, while Bcl-3 deficiency protected mice against TNF/D-GalN induced hepatoxicity and lethality. Consistently, Bcl-3-depleted hepatic cells exhibited decreased sensitivity to TNF-induced apoptosis when stimulated with TNF/CHX. Mechanistically, the in vitro results showed that Bcl-3 interacted with the deubiquitinase CYLD to synergistically switch the ubiquitination status of RIP1 and facilitate the formation of death-inducing Complex II. This complex further resulted in activation of the caspase cascade to induce apoptosis. By revealing this novel role of Bcl-3 in regulating TNF-induced hepatic cell death, this study provides a potential therapeutic target for liver diseases caused by TNF-related apoptosis.Subject terms: Protein folding, Genetics research     

套袋对苹果果实微域生态环境的影响

生长季晴天,树冠不同方位套袋果温度变化规律各有不同。就日最高温度而言,以西南方位套袋果最高,东北方位套袋果最低,二者相差8.13℃。除了东北方位以外,同方位套袋果日最高温一般低于裸露果2 .95～6 .6 7℃。一天中,不同方位套袋果日最高温出现的时间与裸露果有明显不同,主要原因是日照和气温能更直接地影响裸露果。在正常套袋前提下,袋内、外湿度差异不大,袋内湿度主要受袋外环境湿度的影响。生长季晴天,外袋温度和外袋与内袋之间的温度非常接近,二者日最高温度超出最高果温8.6℃。而袋内气温和果温非常接近,二者日最高温仅差0 .4℃,说明袋内果温直接受袋内气温的制约。一天中,袋内最低温度和最高湿度一般出现在6 :0 0左右,而最低湿度和最高温度出现在16 :0 0左右,袋内温度和湿度的变化呈极显著负相关,其回归方程为y=30 98.4 x- 1.35 34。日照强度或气温与套袋果日最高温度均呈极显著正相关。其回归方程分别为:y=0 .0 4 6 8x 8.91和y=1.4 11x- 2 .4 4 35。     

Immune response in COVID-19: what is next?

The coronavirus disease 2019 (COVID-19) has been a global pandemic for more than 2 years and it still impacts our daily lifestyle and quality in unprecedented ways. A better understanding of immunity and its regulation in response to SARS-CoV-2 infection is urgently needed. Based on the current literature, we review here the various virus mutations and the evolving disease manifestations along with the alterations of immune responses with specific focuses on the innate immune response, neutrophil extracellular traps, humoral immunity, and cellular immunity. Different types of vaccines were compared and analyzed based on their unique properties to elicit specific immunity. Various therapeutic strategies such as antibody, anti-viral medications and inflammation control were discussed. We predict that with the available and continuously emerging new technologies, more powerful vaccines and administration schedules, more effective medications and better public health measures, the COVID-19 pandemic will be under control in the near future. Subject terms: Infectious diseases, Antimicrobial responses     

The histone demethylase Kdm6b regulates the maturation and cytotoxicity of TCRαβ+CD8αα+ intestinal intraepithelial lymphocytes

Intestinal intraepithelial lymphocytes (IELs) are distributed along the length of the intestine and are considered the frontline of immune surveillance. The precise molecular mechanisms, especially epigenetic regulation, of their development and function are poorly understood. The trimethylation of histone 3 at lysine 27 (H3K27Me3) is a kind of histone modifications and associated with gene repression. Kdm6b is an epigenetic enzyme responsible for the demethylation of H3K27Me3 and thus promotes gene expression. Here we identified Kdm6b as an important intracellular regulator of small intestinal IELs. Mice genetically deficient for Kdm6b showed greatly reduced numbers of TCRαβ⁺CD8αα⁺ IELs. In the absence of Kdm6b, TCRαβ⁺CD8αα⁺ IELs exhibited increased apoptosis, disturbed maturation and a compromised capability to lyse target cells. Both IL-15 and Kdm6b-mediated demethylation of histone 3 at lysine 27 are responsible for the maturation of TCRαβ⁺CD8αα⁺ IELs through upregulating the expression of Gzmb and Fasl. In addition, Kdm6b also regulates the expression of the gut-homing molecule CCR9 by controlling H3K27Me3 level at its promoter. However, Kdm6b is dispensable for the reactivity of thymic precursors of TCRαβ⁺CD8αα⁺ IELs (IELPs) to IL-15 and TGF-β. In conclusion, we showed that Kdm6b plays critical roles in the maturation and cytotoxic function of small intestinal TCRαβ⁺CD8αα⁺ IELs.Subject terms: Epigenetics, Gene regulation, Immunological disorders, T cells     

用ELISA方法检测稻田捕食者对摇蚊的捕食作用

应用酶联免疫吸附（ELISA）双抗体夹心法,研究了稻田19种常见捕食性天敌对中性昆虫摇蚊的捕食作用。用摇蚊作抗原免疫雄性大白兔获得抗血清,用中和法、双向琼脂扩散实验及交叉反应对所制备的抗血清作特异性检测,抗体反应表明制备的抗血清对摇蚊抗原具有较高的特异性。测定了19种捕食者捕食摇蚊的临界吸收值。在检测的19种捕食者中,有13种捕食了摇蚊,占被检测捕食者种数的67.89％。ELISA阳性反应率最高的是在早稻前期采集的褶管巢蛛,阳性率高达50％,其次是晚稻中期采集的拟水狼蛛,其阳性率为40％。ELISA方法敏感,能快速检测捕食者对猎物的捕食作用及确定节肢类捕食者如蜘蛛对水稻害早控制作用大小,作为一种有效实验工具,可有助于发展水稻害虫综合管理理论。     

二棱大麦和杂种的β-淀粉酶同工酶研究

用水和木瓜蛋白酶提取的两种大麦β-淀粉酶同工酶在薄层等电聚焦电泳中能分辨出30条酶带,它们的pI在4.4—6.5之间,可以分成3个区(Ⅰ、Ⅱ、Ⅲ区)。水提取的游离态β-淀粉酶同工酶主要集中在Ⅰ区。而用木瓜蛋白酶提取的总β-淀粉酶同工酶主要分布在Ⅱ、Ⅲ区,Ⅰ区较少,它的分布区域与游离态酶的活性有关。37个二棱大麦品种的β-淀粉酶活性差异较大,但根据同工酶的电泳图谱可以分成两种类型,即Ⅰ型和Ⅱ型,两者在酶带数和分布上都有差异。 同一类型的不同品种之间杂交后,酶活性出现明显的杂种优势,但其同工酶的电泳图谱不发生改变。 对β-淀粉酶同工酶电泳类型的多型性及高β-淀粉酶活性在育种上的应用作了简要讨论。     

Novel chemically synthesized hydroxyl-containing jasmonates as powerful inducing signals for plant secondary metabolism

Novel hydroxyl-containing jasmonate derivatives were chemically synthesized and evaluated by bioassay as potential elicitors for stimulating the biosynthesis of plant secondary metabolites. A suspension culture of Taxus chinensis, which produces a bioactive taxoid, taxuyunnanine C (Tc), was taken as a model plant cell system. Experiments on the timing of addition of jasmonates and dose response indicated that day 7 and 100 microM was the optimal elicitation time and concentration, respectively, for both cell growth and Tc accumulation. Tc accumulation was increased more in the presence of novel hydroxyl-containing jasmonates compared to that with methyljasmonate (MJA) addition. For example, addition of 100 microM 2,3-dihydroxypropyl jasmonate on day 7 led to a very high Tc content of 47.2 +/- 0.5 mg/g (at day 21), whereas the Tc content was 29.2 +/- 0.6 mg/g (on the same day) with addition of 100 microM MJA. Quantitative structure-activity analysis of various jasmonates suggests that the optimal lipophilicity and the number of hydroxyl groups may be two important factors affecting their elicitation activity. In addition, the jasmonate elicitors were found to induce plant defense responses, including oxidative burst and activation of L-phenylalanine ammonia lyase (PAL). Interestingly, a higher level of H(2)O(2) production and PAL activity was detected with elicitation by the synthesized jasmonates compared with that by MJA, which corresponded well to the superior stimulating activity in the former. This work indicates that the newly synthesized hydroxyl-containing jasmonates can act as powerful inducing signals for secondary metabolite biosynthesis in plant cell cultures.