缺铁敏感度不同的大豆品种对缺铁的适应机制

与供铁处理相比,对缺铁敏感的大豆品种“哈８３”幼苗在缺铁胁迫条件下根际没有酸化现象,根系对Ｆｅ（Ⅲ）的还原能力也没有明显增强。但抗缺铁的大豆品种“８７０１”幼苗根际则严重酸化,根系对Ｆｅ（Ⅲ）的还原能力显著增强;加入能抑制根系Ｈ＋－ＡＴＰ酶活性、减弱根际酸化作用的Ｈ＋－ＡＴＰ酶抑制剂正钒酸钠会降低根系对Ｆｅ（Ⅲ）的还原能力;说明根际酸化与根系还原Ｆｅ（Ⅲ）能力相互联系,初步证实根细胞原生质膜Ｈ＋－ＡＴＰ酶和缺铁诱导的还原酶相互偶联的假说。     

利用假型反转录病毒对大部分胰腺切除后再生细胞的世系追踪

胰腺是一个重要的内外分泌混合腺, 胰腺发生损伤后能够再生。为了探讨胰腺活体细胞世系追踪的方法和胰腺损伤后再生细胞的来源,分别通过胰腺伤口涂抹并胰内注射、尾静脉注射及腹腔注射三种方法, 利用假型反转录病毒对成体小鼠大部分切除后胰腺的细胞进行世系追踪。结果发现在活体条件下, 与尾静脉注射及腹腔注射法相比, 胰腺伤口涂抹并胰腺内注射反转录病毒的方法能够更有效的标记胰腺细胞; 而且, 通过对标记细胞的世系追踪研究证明, 在胰腺损伤后, 胰腺腺泡细胞能够接受损伤信号刺激发生再生。为今后进一步利用反转录假病毒对活体胰腺进行细胞命运追踪研究奠定基础, 为利用反转录病毒载体进行胰腺疾病的基因治疗提供线索。     

Fine mapping and candidate gene analysis of dense and erect panicle 3, DEP3, which confers high grain yield in rice (Oryza sativa L.)

Architecture of the rice inflorescence, which is determined mainly by the morphology, number and length of primary and secondary inflorescence branches, is an important agronomical trait. In the current study, we characterized a novel dense and erect panicle (EP) mutant, dep3, derived from the Oryza sativa ssp. japonica cultivar Hwacheong treated with N-methyl-N-nitrosourea. The panicle of the dep3 mutant remained erect from flowering to full maturation, whereas the panicle of the wild type plant began to droop after flowering. The dep3 mutation also regulated other panicle characteristics, including panicle length, grain shape and grain number per panicle. Anatomical observations revealed that the dep3 mutant had more small vascular bundles and a thicker culm than wild type plants, explaining the EP phenotype. Genetic analysis indicated that the phenotype with the dense and EP was controlled by a single recessive gene, termed dep3. The DEP3 gene was identified as the candidate via a map-based cloning approach and was predicted to encode a patatin-like phospholipase A2 (PLA2) superfamily domain-containing protein. The mutant allele gene carried a 408?bp genomic deletion within LOC_Os06g46350, which included the last 47?bp coding region of the third exon and the first 361?bp of the 3??-untranslated region. Taken together, our results indicated that the patatin-like PLA2 might play a significant role in the formation of vascular bundles, and that the dep3 mutant may provide another EP resource for rice breeding programs.     

Joint structural and physiological control on the interannual variation in productivity in a temperate grassland: A data‐model comparison

Given the important contributions of semiarid region to global land carbon cycle, accurate modeling of the interannual variability (IAV) of terrestrial gross primary productivity (GPP) is important but remains challenging. By decomposing GPP into leaf area index (LAI) and photosynthesis per leaf area (i.e., GPP_leaf), we investigated the IAV of GPP and the mechanisms responsible in a temperate grassland of northwestern China. We further assessed six ecosystem models for their capabilities in reproducing the observed IAV of GPP in a temperate grassland from 2004 to 2011 in China. We observed that the responses to LAI and GPP_leaf to soil water significantly contributed to IAV of GPP at the grassland ecosystem. Two of six models with prescribed LAI simulated of the observed IAV of GPP quite well, but still underestimated the variance of GPP_leaf, therefore the variance of GPP. In comparison, simulated pattern by the other four models with prognostic LAI differed significantly from the observed IAV of GPP. Only some models with prognostic LAI can capture the observed sharp decline of GPP in drought years. Further analysis indicated that accurately representing the responses of GPP_leaf and leaf stomatal conductance to soil moisture are critical for the models to reproduce the observed IAV of GPP_leaf. Our framework also identified that the contributions of LAI and GPP_leaf to the observed IAV of GPP were relatively independent. We conclude that our framework of decomposing GPP into LAI and GPP_leaf has a significant potential for facilitating future model intercomparison, benchmarking and optimization should be adopted for future data‐model comparisons.     

长白山森林动态监测样地鸟兽的红外相机初步监测

<正>长白山国家级自然保护区(41o41′49″–42o25′18″N,127o42′55″–128o16′48″E)位于吉林省东部,面积为196,465 ha,设立于1960年,并于1980年被列为联合国教科文组织世界生物圈自然保护区。保护区内植被垂直带明显,包括针阔混交林(1,100 m以下)、暗针叶林(1,100–1,800 m)、亚高山岳桦(Betula ermanii)林(1,800–2,000 m)和高山苔原(2,000–2,700m)等4个植被带,其中阔叶红松林为该区域的地带性植被(代力民等,2004)。长白山地区野生动植物资源十分丰富,有被子植物98科454属1,190种,兽类     

人食管癌细胞株PTEN的激光共聚焦扫描显微镜检测

目的对人胚食管上皮永生化细胞株SHEE、SHEEMT、食管癌细胞株EC8712中PTEN表达情况进行定量比较和定位观察.方法采用激光共聚焦扫描显微镜光学切片和荧光探针的双重标记技术对三株细胞中PTEN的表达和分布情况进行检测.结果人食管癌细胞中PTEN主要表达在细胞浆和细胞核,在人胚食管癌上皮永生化细胞株SHEE、SHEEMT主要表达在细胞浆,食管癌细胞EC8712中细胞核表达增多,差异有统计学意义(P<0.01);PTEN在三种细胞株中表达强弱顺序为SHEE>SHEEMT>EC8712,差异有统计学意义(P<0.01).结论PTEN在SHEE、SHEEMT和EC8712分化程度不同的细胞株中均表达,表达和分布位置与分化程度相关.     

Highly sensitive determination of the methylated p16 gene in cancer patients by microchip electrophoresis

The p16 tumor suppressor gene is inactivated by promoter region hypermethylation in many types of tumor. Recent studies showed that aberrant methylation of the p16 gene is an early event in many tumors, especially in lung cancer, and may constitute a new biomarker for early detection and monitoring of prevention trials. We detected tumor-associated aberrant hypermethylation of the p16 gene in plasma and tissue DNA from 153 specimens using a modified semi-nested methylation-specific PCR (MSP) combining plastic microchip electrophoresis or slab gel electrophoresis, respectively. Specimens were from 79 lung cancer patients, 15 abdominal tumor patients, 30 positive controls and 30 negative controls. The results showed that the positive rate obtained by microchip electrophoresis was more than 26.6% higher and the same specificity was kept when compared with slab gel electrophoresis. The microchip electrophoresis can rapidly and accurately analyze the PCR products of methylated DNA and obviously improve the positive rate of diagnosis of cancer patients when compared with gel electrophoresis. This method with the high assay sensitivity might be used for detection of methylation of p16 gene and even to facilitate early diagnosis of cancer patients.