脂筏及其在植物细胞中的研究进展

脂筏(lipid rafts)是细胞质膜上富含固醇类和鞘脂类的微结构域,其大小为10~200 nm,是一种高度动态的结构。脂筏假说认为,质膜上一些小而动态的纳米级异质性结构可以通过脂类-脂类、蛋白-脂类和蛋白-蛋白之间的相互作用形成大的反应平台,进而可以介导细胞信号的转导过程。研究表明脂筏具有多种重要的生物学功能,其中包括参与信号转导、跨膜转运、胞吞和胞吐平衡调节、细胞骨架组织以及病原菌入侵等。目前对脂筏的研究还只是近几年才得到快速发展的一个领域,但已经受到越来越多的重视,并且取得初步的研究进展。本文主要介绍了脂筏的特性和生物学功能,尤其对脂筏在植物细胞中的研究进展进行了总结,为今后系统开展脂筏的研究提供理论参考

塔里木河下游浅层地下水变化的生态效应及生态系统健康评价研究

该项目研究提出塔里木河三源流区用水量增加是致使进入塔里木河干流水量减少的主要原因；揭示了断流河道输水后地下水位的动态变化规律；分析了得出地下水是维系塔里木河下游植被生存的惟一水源，地下水埋深对天然植被的组成、分布及物种多样性有直接关系；在分析塔里木河下游地下水位变化与植物生理生态特点关系的基础上，提出了塔里木河下游主要建群种胡杨的合理生态水位、胁迫地下水位和临界地下水位。项目探讨了塔里木河下游生态受损过程和对浅层地下水变化的响应，指出自然因素和人为因素共同作用是塔里木河下游生态环境退化的主要驱动力；并对维持塔里木河生态安全的需水量进行了估算

α-酮戊二酸及其钠盐对雨生红球藻生长和虾青素积累的促进作用

雨生红球藻是已知虾青素(astaxanthin,AST)含量最高的生物,是理想的细胞制备工厂。尽管研究表明添加α-酮戊二酸(OG,α-oxoglutarate)能有效促进混养条件下雨生红球藻AST积累,但在自养条件下是否也有类似效果不清楚。研究以自养雨生红球藻为对象,在正常(CK)、高光(HL)、缺氮(DN)和高光-缺氮双重逆境(HL-DN)下从细胞生长和AST积累两方面评估OG及其钠盐(OG-2Na)的促进作用。结果显示,添加OG或OG-2Na显著缓解HL、DN和HL-DN胁迫对细胞生长的抑制作用,培养至6d的生物量分别为0.58、0.53和0.38g/L,约是未添加组的2.0倍。添加OG或OG-2Na显著促进AST积累。培养至6d,在HL、DN和HL-DN下,AST含量分别达到13.62、19.51和28.29mg/g,是未添加组的2.39、1.16和1.35倍。同时在胁迫条件下,添加OG或OG-2Na有效提高单位细胞中AST含量。针对OG和OG-2Na添加,最大单位细胞AST含量分别出现在HL和HL-DN条件下,达到53.72和60.58pg/cell,是对照的3.09和2.83倍。在CK下,添加10.0mg/L的OG或OG-2Na,其AST含量显著高于单独的胁迫条件。上述结果证实OG或OG-2Na不但可减少HL、DN和HL-DN胁迫对红球藻细胞生长的抑制、显著提高其AST含量,是一种在提高AST产量的有效途径

Identification of blue light receptor phototropin (PHOT) interacting protein from Haematococcus pluvialis and physiological effect of its heterologous expression in tobacco

Photropin (PHOT) is a unique blue light receptor in plants and green algae.Identification of PHOT interacting proteins and their functions will lay a foundation for elucidating PHOT-mediated signaling pathways and physiological functions.In this study,the yeast two-hybridization (Y2H) was used to screen the candidate interacting proteins of HaePHOT from the cDNA library of Haematococcus pluvialis.A total of 23 positive clones were obtained,of which four clones were annotated as DnaJ.The expression correlation of HaePHOT and DnaJ in H.pluvialis showed a strong positive model basing on RNA-Seq data.Further analysis of the expression correlation between HaePHOT or DnaJ and astaxanthin synthetic genes showed that HaePHOT and DnaJ were positively correlated with LYCB,BKT,BCH and CYP97B,but negatively correlated with PSY,PDS,KAS and FAD,respectively.Transient expression assay in tobacco showed that there was no significant difference in chlorophyll a,chlorophyll b and carotenoids contents between wildtype tobacco and HaePHOT-overexpressing tobacco under normal light (white light).However,under blue light,the contents of those pigments were higher in the transient-expression plants than that in the wildtype tobacco.qRT-PCR analysis showed that the expression of genes encoding chlorophyll a oxygenase(CAO),protochlorophyllide oxidoreductase (POR),phytoene synthase (PSY),phytoene desaturase (PDS) and lycopene beta-cyclase (LYCB) were significantly increased under blue light irradiation in the transient-expression tobacco plants,which was consistent with the change pattern of chlorophylls and carotenoids contents.These findings provide a theoretical basis for further revealing the regulatory mechanisms mediated by HaePHOT and its interacting proteins

Phenotypic Characterization of Blue Photoreceptor Plant Type Cryptochrome CRY Mutant in Chlamydomonas reinhardtii

The phenotypic differences of Chlamydomonas reinhardtii wild strain(CC5325)and CRY mutant strain(crcry)under normal CK(Control)and Blue BL(Blue light)cultures were investigated. The PCR verification showed that the crcry mutant was inserted with paromomycin resistance gene AphVIII expression box in the coding region. AphVIII resistance gene was inserted into crcry mutant and successfully expressed in plate and liquid culture system with paromomycin as screening condition. Phenotypic identification showed that there were no significant differences in growth, pigment, photosynthesis and lipid synthesis between wild strain CC5325 and mutant strain crcry under CK culture condition. However, under BL condition, the growth of mutant crcry was significantly inhibited, and the color of algae liquid turned yellow. Chlorophyll a, chlorophyll b and total pigment contents of unit cells decreased significantly, while total carotenoid contents increased significantly. The photosynthetic system was severely suppressed and the total lipid content significantly reduced. In conclusion, plant cry is involved in the blue light response of C. reinhardtii

α-酮戊二酸及其钠盐对雨生红球藻生长和虾青素积累的促进作用

雨生红球藻是已知虾青素(astaxanthin,AST)含量最高的生物,是理想的细胞制备工厂。尽管研究表明添加α-酮戊二酸(OG,α-oxoglutarate)能有效促进混养条件下雨生红球藻AST积累,但在自养条件下是否也有类似效果不清楚。研究以自养雨生红球藻为对象,在正常(CK)、高光(HL)、缺氮(DN)和高光-缺氮双重逆境(HL-DN)下从细胞生长和AST积累两方面评估OG及其钠盐(OG-2Na)的促进作用。结果显示,添加OG或OG-2Na显著缓解HL、DN和HL-DN胁迫对细胞生长的抑制作用,培养至6d的生物量分别为0.58、0.53和0.38g/L,约是未添加组的2.0倍。添加OG或OG-2Na显著促进AST积累。培养至6d,在HL、DN和HL-DN下,AST含量分别达到13.62、19.51和28.29mg/g,是未添加组的2.39、1.16和1.35倍。同时在胁迫条件下,添加OG或OG-2Na有效提高单位细胞中AST含量。针对OG和OG-2Na添加,最大单位细胞AST含量分别出现在HL和HL-DN条件下,达到53.72和60.58pg/cell,是对照的3.09和2.83倍。在CK下,添加10.0mg/L的OG或OG-2Na,其AST含量显著高于单独的胁迫条件。上述结果证实OG或OG-2Na不但可减少HL、DN和HL-DN胁迫对红球藻细胞生长的抑制、显著提高其AST含量,是一种在提高AST产量的有效途径

塔里木河中下游荒漠化防治与生态系统管理研究与示范

该项目成果建立了荒漠区生态环境与经济和谐发展的模式，为正确处理生态环境建设与经济发展的关系提供了理论依据；建立了塔里木河中下游土地利用的5种模式和适宜性评价体系；创立了塔里木河中下游生态经济型植被的模式和结构优化配置方案；提出了6项绿洲灌溉农业节水节肥和棉花高产技术；确定了维护塔里木河中下游至大西海子和台特马湖生态安全的最低年需水量、最佳输水期，提出了塔里木河中下游天然植被合理地下水位的科学依据；揭示了塔里木河中下游30年断流输水后地表生态的响应规律；构建了数字塔河的框架，完成了水、土、植被等23个因子的图层