Expression patterns of a cinnamyl alcohol dehydrogenase gene involved in lignin biosynthesis and environmental stress in Ginkgo biloba

The cinnamyl alcohol dehydrogenase (CAD) is a key enzyme in lignin biosynthesis as it catalyzes the final step in the synthesis of monolignols. A cDNA sequence encoding the CAD gene was isolated from the leaves of Ginkgo biloba L, designated as GbCAD1. The full-length cDNA of GbCAD1 was 1,494?bp containing a 1,074?bp open reading frame encoding a polypeptide of 357 amino acids with a calculated molecular mass of 38.7?kDa and an isoelectric point of 5.74. Comparative and bioinformatic analyses revealed that GbCAD1 showed extensive homology with CADs from other gymnosperm species. Southern blot analysis indicated that GbCAD1 belonged to a multi-gene family. Phylogenetic tree analysis revealed that GbCAD1 shared the same ancestor in evolution with other CADs and had a further relationship with other gymnosperm species. GbCAD1 was an enzyme being pH-dependent and temperature-sensitive, and showing a selected catalyzing. Tissue expression pattern analysis showed that GbCAD1 was constitutively expressed in stems and roots, especially in the parts of the pest and disease infection, with the lower expression being found in two- to four-year-old stem. Further analysis showed the change in lignin content had some linear correlation with the expression level of GbCAD1 mRNA in different tissues. The increased expression of GbCAD1 was detected when the seedling were treated with exogenous abscisic acid, salicylic acid, ethephon, ultraviolet and wounding. These results indicate that the GbCAD1 gene may play a role in the resistance mechanism to biotic and abiotic stresses as well as in tissue-specific developmental lignification.     

腹腔镜手术联合微生态制剂对结直肠癌患者肠道菌群和肠道屏障功能的影响

目的观察腹腔镜手术联合微生态制剂对结直肠癌患者肠道菌群和肠道屏障功能的影响,为临床治疗提供依据。方法选择我院2016年12至2018年12月收治的84例结直肠癌患者为研究对象。入选患者分为观察组和对照组。观察组患者采用腹腔镜手术联合口服益生菌治疗,对照组患者单纯采用腹腔镜手术治疗。比较两组患者术后恢复情况、并发症情况、肠道菌群变化和肠道屏障功能。结果观察组患者第1次完全进食时间、术后住院总时间(d)均短于对照组(9.54±0.52 vs 11.56±0.24、11.61±2.14 vs 14.94±3.65,P<0.05);观察组患者术后并发症总发生率低于对照组(9.5%vs 28.6%,P<0.05)。观察组患者术后第1次排便时肠道乳杆菌、双歧杆菌数量(lg CFU/g)大于对照组(7.21±0.35 vs 6.78±0.21、7.12±0.23 vs 6.84±0.25,P<0.05),大肠埃希菌、球杆菌数量低于对照组(8.12±0.56 vs 9.55±0.54、8.24±0.24 vs 8.85±0.25,P<0.05)。观察组患者术后第15天肠道乳杆菌、双歧杆菌数量大于对照组(9.51±0.56 vs 8.21±0.45、9.61±0.44 vs 7.85±0.23,P<0.05),大肠埃希菌、球杆菌数量低于对照组(7.22±0.36 vs 9.15±0.35、7.68±0.54 vs 8.25±0.55,P<0.05)。观察组患者术后第15天粪便sIgA水平(mg/g)大于对照组(1.21±0.13 vs 1.05±0.14,P<0.05);血清D-乳酸、尿L/M水平(μg/mL)低于对照组(5.48±0.85 vs 0.62±0.54、3.24±0.28 vs 2.68±0.54,P<0.05)。结论腹腔镜手术联合益生菌制剂可纠正并改善结直肠癌患者术后肠道微生态失调,修复并增强肠道屏障功能。     

Properties of plate meristem of growing epigeal cotyledons in an experimental system

Plate meristem activity in epigeal cotyledons of plants, which are largely used in research, was comparatively studied. Formation of growing clusters of daughter cells is a common feature of cotyledon meristems. Species-specific differences connected with the number of cells entering division, the homogeneity of the palisade cell population, tissue specification of proliferation, the end number of daughter cells in clusters and the possibility to use clusters for simultaneous determination of the cell growth and division activity are shown. Exogenous cytokinin enlarges the number of cells entering proliferative divisions in the division competent tissues of the respective cotyledon and stimulates the growth of isolated cotyledons cultured in darkness. The analysis of morphological peculiarities substantiates the properties of the meristems of studied species in an experimental system and the possible light microscopy approach for using them in obtaining data on the number of divisions and accompanying cell growth. The first palisade layer of zucchini cotyledon was chosen as the most suitable experimental system reflecting the cellular behaviour during the growth of a plant organ and permitting easy and exact quantification of the cell divisions and growth simultaneously.     

楮实子油精提前后脂肪酸的GC-MS分析比较

首次采用皂化、水解和冷冻等方法纯化楮实子油中的不饱和脂肪酸,确定较好的皂化条件为:碱含量为原油重的35%,温度为80~90℃;冷冻处理的最佳条件为:加5倍楮实子油重的丙酮溶解后,置入-8~-10℃保持48 h,去掉饱和脂肪酸,可使不饱和脂肪酸的含量由65%提高到88%。     

The potential therapeutic of siRNA eye drops in ocular diseases

In recent years, researchers have expressed an ongoing interest in developing RNA interference (RNAi) technology for therapeutic gene suppression in various diseases. Preclinical studies in animal models and cultured cell studies indicated that RNAi technology was an effective experimental tool against a variety of ocular diseases, and some small interference RNA (siRNA) drugs have been entered into clinical trials in Stage I and Stage II. However, in these studies siRNAs were delivered into ocular tissues via either systemic or subconjunctival/intravitreous injection, which is invasive and harmful if repeated. Based on this evidence, we hypothesize that topical application of siRNA eye drops may be a safe and effective therapeutic option in ocular surface diseases with temporary changes of gene expression. Furthermore, siRNA eye drops targeting different genes may simultaneously treat several ocular surface diseases.     

应用CTAB法对砂梨品种DNA提取效果的研究

为了获得质量较好的DNA,我们采用CTAB法对11个砂梨品种的叶片DNA提取情况进行了研究,发现参试样品中一些样品的蛋白质含量较多,而另外一些样品的多糖、酚类物质含量较高。对于蛋。白质含量较多的这类材料,适当增加24：1的处理次数能够使蛋白质沉淀下来;对于多糖、酚类物质含量较高的材料,用5mol／L的NaCl和3mol／L的NaAc等处理能够有效的降低多糖含量。另外,对研磨样品的加入量和PVP的加入时间进行了对比,最后用双酶切、电脉检测等不同的分析方法对所得到的DNA提取物的浓度和纯度进行检测,发现加入样品量在0．3g左右、在研磨后的粗提液中加入PVP,所得到的DNA质量较好.     

B交配型因子对香菇双核体核型分离比的影响

通过探明A或B交配型因子对双核体回收核型的影响,探讨了香菇双核体经原生质体形成和再生后两个成员核偏分离现象的遗传基础。结果表明,B因子或某些假定的与B因子连锁的基因明显影响去双核化后核的存活力,而A因子对此无明显影响。B因子的特异性与分离自两类异核体（A≠B≠和A=B≠）回收的成员核的存活比例密切相关。可以根据这种功能将B因子排成一个分级的序列。两个参试菌株中的4个B因子的特异性顺序为B1〉B3〉B4〉B2。     

<Emphasis Type="Italic">ADH</Emphasis> and <Emphasis Type="Italic">PDC</Emphasis> genes involved in tannins coagulation leading to natural de-astringency in Chinese pollination constant and non-astringency persimmon (<Emphasis Type="Italic">Diospyros kaki</Emphasis> Thunb.)

Pollination constant non-astringency (PCNA)-type persimmons are the most desirable cultivar because the fruit loses astringency naturally and does not require any treatments for edibility. The mechanism of natural astringency loss in Chinese PCNA (C-PCNA)-type persimmon is probably related to the coagulation of soluble tannins into insoluble tannins, which is quite different from that in the Japanese PCNA (J-PCNA) type. In this work, three types of persimmon cultivars were sampled: ‘Luotian-tianshi’ (C-PCNA), ‘Maekawa-jirou’ (J-PCNA), and ‘Mopanshi’ (pollination constant astringent (PCA)) were sampled. Three DkADH and four DkPDC genes were isolated from C-PCNA plants. Three candidate genes for soluble tannins coagulation identified in C-PCNA fruit (DkADH1, DkPDC1, and DkPDC2) were characterized through combined analysis of spatiotemporal expression patterns and tannin and acetaldehyde contents during fruit development. Transient over-expression in persimmon leaves showed that DkADH1 and DkPDC2 led to a significant decrease in the levels of soluble tannins in infiltrated leaves. These results indicated that DkADH and DkPDC genes should be considered key genes for natural astringency loss in C-PCNA types.     

June–September temperature reconstruction in the Northern Caucasus based on blue intensity data

Although long-lived trees grow in the Northern Caucasus, no single tree-ring chronology has been reported thus far from this area in the International Tree-Ring Data Base (ITRDB), neither has one been published in international journals. Extensive tree-ring studies were conducted over the last decade, and a tree-ring network was developed for the investigated area. The data on the minimum blue intensity based on 33 series of pine (Pinus sylvestris L.) and fir (Abies nordmanniana (Steven) Spach) is presented in this study. The minimum blue intensity (BI) chronology covers the period 1596–2011 with EPS value ≥0.85. The BI chronology strongly correlates with the mean June-September temperature (R = 0.74; p < 0.05) from the weather station “Kluhorskij Pereval” (1951–2011). Mean June-September temperature anomalies were reconstructed using the rescaling method. Based on the reconstruction provided in this study the twentieth century is characterized by highly increased June-September temperature. According to this study, the minimum blue intensity approach demonstrates a great potential for paleoclimatic research in the Caucasus. Vast spatial coverage of the new BI-based reconstruction based on data from only two locations in the Northern Caucasus provides prospects for reconstruction of temperature variations for a great region in the Middle East and Northern Africa.     

Modification of chrysanthemum odour and taste with chrysanthemol synthase induces strong dual resistance against cotton aphids

Aphids are pests of chrysanthemum that employ plant volatiles to select host plants and ingest cell contents to probe host quality before engaging in prolonged feeding and reproduction. Changes in volatile and nonvolatile metabolite profiles can disrupt aphid–plant interactions and provide new methods of pest control. Chrysanthemol synthase (CHS) from Tanacetum cinerariifolium represents the first committed step in the biosynthesis of pyrethrin ester insecticides, but no biological role for the chrysanthemol product alone has yet been documented. In this study, the TcCHS gene was over‐expressed in Chrysanthemum morifolium and resulted in both the emission of volatile chrysanthemol (ca. 47 pmol/h/gFW) and accumulation of a chrysanthemol glycoside derivative, identified by NMR as chrysanthemyl‐6‐O‐malonyl‐β‐D‐glucopyranoside (ca. 1.1 mM), with no detrimental phenotypic effects. Dual‐choice assays separately assaying these compounds in pure form and as part of the headspace and extract demonstrated independent bioactivity of both components against the cotton aphid (Aphis gossypii). Performance assays showed that the TcCHS plants significantly reduced aphid reproduction, consistent with disturbance of aphid probing activities on these plants as revealed by electropenetrogram (EPG) studies. In open‐field trials, aphid population development was very strongly impaired demonstrating the robustness and high impact of the trait. The results suggest that expression of the TcCHS gene induces a dual defence system, with both repellence by chrysanthemol odour and deterrence by its nonvolatile glycoside, introducing a promising new option for engineering aphid control into plants.