接种内生菌对干旱胁迫下甘蔗的生理影响

探索内生菌对甘蔗抗旱能力的影响,以期为开发利用甘蔗内生菌抗旱性功能菌株提供理论依据和技术支撑.以课题组前期分离鉴定的6株甘蔗内生菌为供试菌株,甘蔗品种'ROC22'幼苗接种7天后进行干旱胁迫,然后取完全展开的第一叶叶片测定相关生理指标.结果 表明,E3、09和YC89均有较高的ACC脱氨酶活性,不同甘蔗内生菌菌株对甘蔗...     

光照和生长阶段对菖蒲根系泌氧的影响

以自然湖泊沉积物为研究基质,利用微型电机控制溶氧微电极实现纵向精确微位移,在照光与遮光条件下,对典型湿地植物菖蒲幼苗、成株根系根基部起总根长1/4处(根1/4)、根系中部(根1/2)、从根基部起总根长3/4处(根3/4)及根尖(根1)处根系微界面径向溶氧浓度变化进行原位精确测定.结果表明:无论有无光照,菖蒲幼苗、成株根系不同部位均存在从根表面至沉积物氧饱和度由高到低的氧扩散层,其厚度0.18-0.68 mm;根1/2、3/4、1处氧扩散能力菖蒲成株较幼苗显著增强(P＜0.01),根1/4处二者则无显著差异(P＞0.05);光照对菖蒲幼苗、成株根系不同部位氧扩散能力的影响存在差异,光照对菖蒲幼苗根1/2及菖蒲成株根1/2、根3/4处影响显著(照光组显著高于遮光组,P＜0.01),而对菖蒲幼苗根1/4、根3/4、根1及菖蒲成株根1/4、根1处无显著影响(P＞0.05);从根系泌氧空间差异上看,照光条件下菖蒲幼苗、成株分别表现为根1/2＞根3/4≈根1≈根1/4 (P＜0.01,P＞0.05)和根1/2＞根3/4＞根1＞根1/4( P＜0.01),遮光条件下菖蒲幼苗、成株分别表现为根1/2≈根3/4≈根1≈根1/4( P＞0.05)和根1/2＞根3/4≈根1＞根1/4( P＜0.01,P＞0.05).     

矿区植物根内嗜鱼外瓶霉对重金属的耐性和超积累作用

从云南会泽铅-锌矿区自然生长植物密序野古草(Arundinella bengalensis(Spreng.)Druce)的健康根内分离得到一株深色有隔内生真菌(dark septate endophytes,DSE)。据其形态学特征和ITS1-5.8S-rDNA-ITS2序列分析,鉴定为一株嗜鱼外瓶霉(Exophiala pisciphila)。纯培养条件下研究了其对Pb2+、Zn2+、Cd2+的耐性和超积累作用。结果表明,此菌株在液体合成培养基上可以分别耐受2、3和0.5 g/L的Pb2+、Zn2+和Cd2+;在含Pb2+、Cd2+培养基中生长其菌丝可以富集超过其干重25%以上的Pb2+和5%以上的Cd2+;显示此菌株属于极端耐性并具有超积累作用的真菌。此真菌在植物根系的定殖或许可以通过菌丝体对金属离子的固持作用缓解植物根围土壤微环境中超量金属离子对植物的毒害作用。     

The effects of triacontanol on seedling growth and polyphenol oxidase activity in dark and light growth lettuce

The present study was designed to study the effects of various concentrations (0.00; 0.01, 0.10 and 1.00‐mg/ml) of triacontanol on root, stem and leaf growth and polyphenol oxidase activity in each respective tissue; in Grand Rapids and Great Lakes varieties of eleven‐day‐old dark and light grown lettuce seedlings.

Root, stem and leaf growth was less than in non‐triacontanol‐treated Grand Rapids seedlings in both TC‐treated dark and light exposed seedlings. With respect to Great Lakes seedlings, all dark‐grown roots exhibited greater growth than the corresponding untreated control. Light‐grown Great Lakes roots treated with 0.01‐mg/ml and 1.0‐mg/ml or triacontanol respectively, grew more than control or 0.1‐mg/ml triacontanol‐treated seedlings. Both dark and light‐grown triacontanol‐treated stem and leaf tissues of Great Lakes seedlings all produced less growth than the untreated controls.

The Grand Rapids variety had less polyphenol oxidase activity in both dark and light‐grown root and stem tissues than in untreated controls; however, both dark and light‐grown leaf tissue, treat ed with 0.01‐mg/ml and 1.0‐mg/ml of triacontanol respectively exhibited more polyphenol oxidase activity than 1.0‐mg/ml triacontanol ‐treated or untreated control tissues.

TC treatment of 0.1‐mg/ml caused no enhancement of PPO activity in dark or light‐grown root, stem and leaf tissues of Great Lakes tissue, however, seedlings treated with a concentration of 0.01‐mg/ml TC exhibited more PPO activity than non‐TC‐treated controls.     

光照处理对发芽燕麦中多酚类物质含量及抗氧化活性的影响

【目的】研究光照处理对发芽燕麦中多酚类物质含量及抗氧化活性的影响。【方法】将燕麦籽粒分为光照组和黑暗组,浸泡后分别在光照（光照强度为200 μmol/(m²·s)）和遮光条件下进行发芽,在发芽24,48,72和96 h时取样,提取样品中的游离态和结合态多酚,测定多酚、黄酮含量及肉桂酸、阿魏酸、没食子酸、对香豆酸、咖啡酸这5种主要酚酸的组分变化。测定游离态和结合态多酚提取物的抗氧化活性（ABTS、DPPH自由基清除能力和铁还原能力）,分析游离态和结合态多酚、黄酮含量与3种抗氧化指标间的相关性。【结果】光照处理下发芽燕麦中游离态和结合态多酚、黄酮含量明显高于黑暗组。游离态多酚提取物中,光照组样品中没食子酸、咖啡酸、阿魏酸含量在发芽过程中总体高于黑暗组,对香豆酸和肉桂酸的含量总体低于黑暗组;5种酚酸的总量在发芽前期（发芽24~48 h）光照组略低于黑暗组,发芽后期（发芽72~96 h）显著高于黑暗组。结合态多酚提取物中,除肉桂酸外,其余4种酚酸的含量在发芽过程中均表现为光照组显著高于黑暗组;在发芽过程中,光照组5种酚酸的总量显著高于黑暗组。光照组样品的游离态和结合态多酚提取物的抗氧化活性均显著高于黑暗组。2种处理下,除游离态黄酮外,发芽燕麦中的多酚、结合态黄酮均与其抗氧化活性间存在显著正相关。【结论】光照处理可有效提高发芽燕麦中多酚物质的含量及其抗氧化活性。     

海南省暗红湿润铁铝胶园土壤肥力综合评价及时空变化研究

本文通过对海南省不同割龄暗红湿润铁铝胶园地的土壤肥力进行评价分析,其评价结果表明,海南省不同割龄暗红湿润铁铝胶园的土壤肥力普遍较低,综合评价指标值介于0.24～0.50之间。不同割龄湿润铁铝胶园土壤综合评价指标值大小,0～10年（0.26）＞30～年（0.24）＞10～20年（0.23）＞20～30年（0.23）,且各割龄段综合评价指标值都低于0.4;不同纬度湿润铁铝胶园土壤综合评价指标值大小,海口（0.35）＞临高（0.25）＞澄迈（0.24）＞文昌（0.23）;不同经度湿润铁铝胶园土壤综合评价指标值大小,定安（0.50）＞海口(0.35)＞琼海（0.34）＞万宁（0.23）。且不同割龄,不同地区综合肥力都较差。     

Natural Polyether Ionophores and Their Pharmacological Profile

This review is devoted to the study of the biological activity of polyether ionophores produced by bacteria, unicellular marine algae, red seaweeds, marine sponges, and coelenterates. Biological activities have been studied experimentally in various laboratories, as well as data obtained using QSAR (Quantitative Structure–Activity Relationships) algorithms. According to the data obtained, it was shown that polyether toxins exhibit strong antibacterial, antimicrobial, antifungal, antitumor, and other activities. Along with this, it was found that natural polyether ionophores exhibit such properties as antiparasitic, antiprotozoal, cytostatic, anti-mycoplasmal, and antieczema activities. In addition, polyethers have been found to be potential regulators of lipid metabolism or inhibitors of DNA synthesis. Further study of the mechanisms of action and the search for new polyether ionophores and their derivatives may provide more effective therapeutic natural polyether ionophores for the treatment of cancer and other diseases. For some polyether ionophores, 3D graphs are presented, which demonstrate the predicted and calculated activities. The data presented in this review will be of interest to pharmacologists, chemists, practical medicine, and the pharmaceutical industry.     

立枯丝核菌诱导下深色有隔内生真菌A024代谢组学分析

为研究深色有隔内生真菌(Phialocephala bamuru)A 024时立枯丝核菌(Rhizoctonia solani Kühn)的抑制机制,本研究从采用LC-MS分析平台对立枯丝核菌诱导条件下深色有隔内生真菌A024的非靶向代谢组进行分析.结果 表明菌株A024代谢产物包括9大类,27小类,筛选得到52个差异...     

湖南益阳黑茶中桔青霉线粒体全基因组序列测定及分析

对黑茶中分离的一株桔青霉线粒体基因序列进行测定与分析,并探究其与近缘种微生物的系统发育关系。结果表明,桔青霉线粒体基因组是一条全长27β537βbp的环状DNA分子,共编码42个基因（15个蛋白质编码基因,2个rRNA,24个tRNA以及1个独立的ORF）,基因组碱基构成为：A（36.17%）、T（37.06%）、C（11.82%）、G（14.95%）。15个蛋白质编码基因均采用典型的ATG作为起始密码子、TAA或TAG作为终止密码子,基因排列顺序与已报道的青霉属物种相似,在进化上较为保守。蛋白质编码基因编码频率较高的氨基酸分别为Leu、Ile、Ser和Phe;RSCU频率最高的4个密码子依次是UUA、AUA、UUU和GGU。24个tRNA基因存在30处G-U错配,均可形成典型三叶草结构。系统发育分析结果表明,桔青霉分类地位上关系最密切是Penicillium ShG4C,其次是Penicillium polonicum与Penicillium nordicum。