时间序列修订对森林二氧化碳通量的影响

对长白山阔叶红松林2003年生长季的涡动相关实测时间序列进行了去倾修订与超声风速仪倾斜修订,并分析了不同修订方法对森林CO2通量计算值的影响．结果表明,基于未修订时间序列计算得到的森林CO2通量(Fcraw)被高估．线性与非线性去倾对Fcraw的修订量分别为1．6％、1．8％,两者差异很小．平面拟合坐标变换与流线坐标变换对Fcraw的修订量分别为3．7％、4．7％,两者差异较大．对线性去倾后的时间序列分别进行流线坐标变换与平面拟合坐标变换,二者对Fcraw的修订量分别为5．5％与4．6％．建议对时间序列进行线性去倾与平面拟合坐标变换综合修订．     

Expression of chemokine-like factor 1 is upregulated during T lymphocyte activation

Chemokine-like factor 1 (CKLF1) is a cytokine with chemotactic effects on leukocytes and a functional ligand of CCR4. This cytokine is widely expressed and the level of expression is reported to be upregulated in asthma and rheumatoid arthritis (RA), disease conditions in which T lymphocytes are over-activated. In order to determine the expression profile of CKLF1 in activated T lymphocytes, we first employed a PCR-based method on human blood fractions cDNA panels and found that CKLF1 was upregulated in activated CD4+ and CD8+ cells, with no obvious changes in CD19+ cells. We further performed kinetic analyses of CKLF1 expression in phytohemagglutinin (PHA)-stimulated human peripheral blood lymphocytes (PBL) at both the mRNA and protein levels. In resting PBL, the constitutive expression of CKLF1 was low at mRNA level and barely detectable at the protein level; however, both were remarkably upregulated by PHA, appearing at 8h after PHA-stimulation and persisting up to 72h. These results suggest that CKLF1 may be involved in T lymphocyte activation and further study of CKLF1 function will prove valuable.     

黄孢原毛平革菌抗营养阻遏产漆酶诱变育种及其产酶特性

【目的】筛选能抗营养阻遏产漆酶的黄孢原毛平革菌,论证其产漆酶的确定性及抗营养阻遏产木质素酶的可行性,为白腐菌产酶代谢调控、木质素降解机理的研究奠定基础。【方法】利用重复紫外诱变法,以愈创木酚富氮鉴别培养基筛选目标菌株;比较不同营养条件下菌体生长与产酶动力学差异研究产酶营养调控机理;通过热处理、排除锰离子和加入过氧化氢酶等不同措施论证黄孢原平毛平革菌能否产生漆酶。【结果】3种不同方法均证实选育到的pcR5305和pcR5324菌株在限氮与富氮条件下均能产生漆酶,pcR5305和pcR5324在限氮条件下产漆酶分别达到203.5、187.6 U/L;在富氮条件下为220.6、183.9 U/L,而原菌株pc530在两种条件下都基本不产生漆酶。二菌株产漆酶调控方式不同,pcR5305漆酶产生与菌体生长同步,而pcR5324漆酶产生却受营养氮阻遏。二菌株同时具有抗营养阻遏高产木质素过氧化物酶(LiP)和锰过氧化物酶(MnP)(分别为LiP 1343.2、MnP 252.2 U/L;LiP 1169.5、MnP 172.4 U/L)的能力。【结论】筛选到的黄孢原毛平革菌变异菌株能产漆酶,同时表现了抗营养阻遏产漆酶、木质素过氧化物酶和锰过氧化物酶的能力,具有重要的生产应用与理论研究价值,为白腐菌产酶代谢调控机理研究提供了原始菌株并奠定了良好的基础。     

Characterization of a novel nm23 gene and its potential roles in gametogenesis in the prawn Macrobrachium rosenbergii (de Man, 1879) (Crustacea: Decapoda)

Nm23 is a family of genes encoding the nucleoside diphosphate (NDP) kinase, which functions in a wide variety of biological processes, including growth, development, differentiation and tumor metastasis. In this study, a novel nm23 gene, designated as Mrnm23, was identified from the freshwater giant prawn Macrobrachium rosenbergii. The full-length cDNA was 776 bp in length, encoding for a protein of 176 amino acids with one typical NDP kinase domain that harbored all the crucial residues for nucleotide binding and enzymatic activity. Like human novel nm23-H1B, the putative protein contained a unique 21-amino-acid NH₂-terminal extension as compared to human nm23 (nm23-H1) homologs. Further, 3 extra amino acid residues prolonged the COOH-terminus. The Mrnm23 was ubiquitously expressed in all tissues examined, including androgenic gland, gill, heart, liver, muscle, ovary, and testis. In situ hybridization to gonad sections indicated that the Mrnm23 mRNA was localized in the cytoplasm of cup-base of differentiating spermatids, in the spike of the umbrella-shaped spermatozoa and in the cytoplasm of the early previtellogenic oocytes, suggesting that the Mrnm23 has potential roles in spermiogenesis and early differentiation of oocyte.     

Physiological dormancy in seeds of two endemic species of Begonia from Yunnan Province,China: diagnosis and classification

With the purpose of assessing the status of dormancy in seeds of two Begonia species (Begonia lithophila and Begonia guishanensis), freshly matured seeds were given gibberellic acid and moist chilling and allowed to dry after ripening. The seeds were then germinated on media with or without KNO₃ at 15, 20, 25, 30 and 18/25°C. All three treatments significantly increased germination percentages. Examination by X‐ray revealed that seeds of both species have a fully developed embryo and thus have no morphological component of dormancy; seeds readily imbibed water and KNO₃ solution. Therefore, we conclude that seeds of the two Begonia species have non‐deep physiological dormancy. Although KNO₃ significantly increased germination in both species, alternating temperatures did not, suggesting that the most favorable microhabitat for germination is small‐scale disturbances under the forest canopy.     

水杨酸、茉莉酸和乙烯在调控蚕豆气L运动中的相互关系

以蚕豆下表皮为材料研究了水杨酸、(±)茉莉酸和乙烯对气孔运动的影响及其相互关系。结果表明,在一定范围内,水杨酸和乙烯利都可诱导气孔关闭,并且二者能够相互增强其作用强度;(±)茉莉酸能够促进气孔开度增大,加入(±)茉莉酸减弱了乙烯利对气孔运动的影响,(±)茉莉酸和乙烯利存在拮抗效应。降低内源乙烯的水平可以增强(±)茉莉酸促进气孔张开的作用、降低水杨酸的诱导气孔关闭效应。而水杨酸和(±)茉莉酸之间的关系比较复杂。