Salt pollution in a Japanese stream and its effects on water chemistry and epilithic algal chlorophyll-a

Concentrations of major ions, total phosphorus, dissolved organic carbon, biological oxygen demand and chlorophyll-a of epilithic algae were determined weekly at nine sites in a Japanese stream receiving effluent from a groundwater treatment plant. The concentrations of four major cations (Na, K, Ca and Mg) and chloride ion increased significantly immediately at downstream sites of the effluent outfall. The ionic concentrations decreased with increasing dilution from merging tributaries but never reached the original concentrations and relative composition of stream water within a 10.7 km stream distance from the outfall. The changes in total ionic concentration and relative ionic proportion also changed the chlorophyll-a content of epilithic algae. The results also showed significantly higher chlorophyll-a content in epilithic algae under moderate salinity.     

Salinity induced nuclear and DNA degradation in meristematic cells of soybean (Glycine max (L.)) roots

Changes in the nuclei of meristematic root cells of soybean (Glycine max (L.) Merr. cv. Acme) in response to severe salinity were studied. Root growth was inhibited by 200 mM NaCl, when 1 mM CaCl_2 was present in the culture media. Increasing CaCl_2 up to 5 mM partially prevented this inhibition. However, inhibition also occurred with 100~mM NaCl without CaCl_2. We examined the meristematic cells under a series of NaCl treatments. Nuclear deformation of the cells occurred with 24 h of 150 mM or higher NaCl, and was followed by degradation of nuclei in the apical region of the root. TEM observation and agarose gel electrophoretic analysis confirmed that root tip nuclear DNA deformed or degraded with 150 mM or higher NaCl concentrations.     

盐胁迫对大麦幼苗质膜,液泡膜上共价和非共价结合多胺含量的影响

用不同浓度ＮａＣｌ处理７ｄ龄大麦（Ｈｏｒｄｅｕｍ ｖｕｌｇａｒｅＬ．）幼苗３ｄ。以非共价键和共价键形式分别与质膜和液泡膜微囊及膜蛋白结合的多胺含量受低 度盐的促进而被高浓度盐所抑制。以非共价键形式与膜微囊结合的各种多胺中亚精胺（Ｓｐｄ）含量最高,占膜上多胺总量的４０％－７０％,与膜蛋白共价结合的各种多胺中腐胺（Ｐｕｔ）含量占主导地位,占膜蛋白上多胺总量的３５％－６０％。在根系液泡膜上发现一种含量丰     

Transformation of Brassica juncea (L.) Czern with bacterial codA gene enhances its tolerance to salt stress

The codA gene for biosynthesis of glycinebetaine from Arthrobacter globiformis was used for transforming Brassica juncea cv. Pusa Jaikisan (which lack any means to synthesize glycinebetaine) through Agrobacterium mediated transformation. The stable insertion of the codA gene in the shoots obtained on medium with kanamycin and hygromycin was confirmed by PCR analysis of the nptII gene. Southern hybridization with a codA probe further demonstrated its successful integration. Immunoblot analysis revealed the presence of choline oxidase demonstrating that the bacterial codA gene had been successfully transcribed and translated. The seeds of transgenic lines showed enhanced capacity to germinate under salt stress as compared to that of the wild type. Further, the seedlings of transgenic plants that expressed codA gene showed significantly higher growth than that of the wild type under salt stress conditions. These results demonstrated that the introduction of a biosynthetic pathway for glycinebetaine into Brassica juncea significantly enhanced their salt tolerance. Hence, homozygous genotypes of selected transformed lines can be exploited for improving the salt tolerance of the desirable cultivars of Brassica juncea through breeding programmes.     

多胺浸种改善盐胁迫大麦根系液泡膜功能的机理

研究了0.1 mmol/L 腐胺 (Put) 和0.5 mmol/L 亚精胺 (Spd) 浸种对200 mmol/L NaCl胁迫下大麦(Hordeum vulgare L.)幼苗生长速率、干物质积累、离子分布、液泡膜蛋白结合多胺含量以及液泡膜膜脂组分与功能的影响.结果表明,Put和Spd浸种均可缓解盐胁迫对大麦幼苗的盐害,促进生长和干物质积累,降低大麦幼苗体内[Na+]/[K+].与盐处理的对照植株相比,Put和Spd浸种均可提高大麦幼苗根系液泡膜磷脂含量,降低糖脂结合半乳糖含量,而膜上非共价结合多胺含量Spd+PAx (一种未知多胺) 与 Put+Dap (二氨基丙烷)之比((Spd+PAx)/(Put+Dap))、共价和非共价结合多胺总量均上升.统计分析结果表明,液泡膜非共价结合多胺(Spd+PAx)/(Put+Dap)与H+-ATPase和H+-PPase活性呈显著正相关关系.     

Changes in Physiological Properties and Respiratory Pathway of the New Lines of Wheat Introduced Exogenous DNA Under Salt Stress

New lines of wheat (Triticum aestivum L.) was obtained by introducing the DNA of sorghum ( Sorghum vulgare Pers.) into wheat cultivar “Longchun 13”. The changes of respiratory pathway, contents of protein, Na+ and K+ in the leaves and roots of the new lines of wheat under salt stress were determined and compared with the control cultivar, “Longchun 13”. The decrease of the content of K+ was observed with the increase of NaCl concentrations, but the decrease was more in the control than that in the new lines, and more in roots than in leaves. Content of proline and Na+ in both two wheats lines increased greatly, but the former increased more significantly in the new lines and the latter more significantly in control both in leaves and roots. The operation of the cyanide-resistant pathway of respiration was enhanced at different degrees after salt stress and it increased much more in roots and leaves of the control plant than that in the new lines, but the cytochrome pathway of electron transport was still the main one consistently. The possible significance of these changes was discussed.     

水稻受盐抑制基因OsZFP1的转基因分析

OsZFP1(水稻锌指蛋白1)基因编码的蛋白含有3个推测的Cys2/Cys2-型锌指结构域,它的表达受盐胁迫负调控.构建了以35S为启动子的OsZFP1基因的植物表达载体,并将其转入拟南芥(Arabidopsis thaliana L.)植物和水稻(Oryza sativa L.)愈伤组织中以过量表达OsZFP1基因.转基因的拟南芥植株和水稻愈伤组织对盐处理的敏感性都比野生型要高.这一结果表明OsZFP1基因可能编码一种负调控蛋白,它可能抑制某些盐诱导基因的表达.在ABA处理下,转基因拟南芥植株比野生型植株抽苔晚,说明OsZFP1基因的作用可能受ABA调节.     

酿酒酵母HAL1基因的克隆及植物表达载体的构建

HAL1基因是酵母中重要的耐盐基因。以酿酒酵母AS2.375菌株的DNA为模板,根据已发表的序列设计引物,经PCR扩增得到约900 bp的HAL1基因片段,连接到pMD18-T载体上,转化大肠杆菌JM109,筛选重组质粒进行酶切分析和序列测定,结果显示已克隆到完整的可读框,该基因的序列与已知序列同源性达99%。将HAL1基因从T-载体上切下连接到pAM194载体上构建了HAL 1基因的植物表达载体,用于烟草的转化获得了耐盐性提高的转化植株。     

Hallstatt miners consumed blue cheese and beer during the Iron Age and retained a non-Westernized gut microbiome until the Baroque period

Download : Download video (38MB)