Compositional characterization and imaging of “wall-bound” acylesters of Populus trichocarpa reveal differential accumulation of acyl molecules in normal and reactive woods

Acylesterification is one of the common modifications of cell wall non-cellulosic polysaccharides and/or lignin primarily in monocot plants. We analyzed the cell-wall acylesters of black cottonwood (Populus trichocarpa Torr. & Gray) with liquid chromatography-mass spectrometry (LC-MS), Fourier transform-infrared (FT-IR) microspectroscopy, and synchrotron infrared (IR) imaging facility. The results revealed that the cell wall of dicotyledonous poplar, as the walls of many monocot grasses, contains a considerable amount of acylesters, primarily acetyl and p-hydroxycinnamoyl molecules. The "wall-bound" acetate and phenolics display a distinct tissue specific-, bending stress responsible- and developmental-accumulation pattern. The "wall-bound" p-coumarate predominantly accumulated in young leaves and decreased in mature leaves, whereas acetate and ferulate mostly amassed in the cell wall of stems. Along the development of stem, the level of the "wall-bound" ferulate gradually increased, while the basal level of p-coumarate further decreased. Induction of tension wood decreased the accumulation of the "wall-bound" phenolics while the level of acetate remained constant. Synchrotron IR-mediated chemical compositional imaging revealed a close spatial distribution of acylesters with cell wall polysaccharides in poplar stem. These results indicate that different "wall-bound" acylesters play distinct roles in poplar cell wall structural construction and/or metabolism of cell wall matrix components.     

江西珍稀濒危植物优先保护定量研究

以江西省50种珍稀濒危植物为定量研究对象,采用以濒危系数、遗传价值系数、物种价值系数和生物学特征系数4个指标构成的珍稀濒危植物等级综合评价值的方法对上述植物优先保护顺序进行了定量研究。对50种珍稀植物进行排序的结果基本符合《中国珍稀濒危植物》和《中国植物红皮书》第1册的分析,但也有不同：属一级保护的有长柄双花木、天目木姜子和长序榆等共10种,占研究物种总数的20．00％,其中有浙江楠和华东黄杉等2渐危种;二级保护的有胡豆莲、连香树、伯乐树、银钟花等共26种,占52．00％,其中胡豆莲属于濒危种;三级的有小花木兰、观光木等12种,占24．00％,其中有4种属稀有种,8种属渐危种;此外,八角莲、野大豆等在江西可以暂不列入保护,这两者均属渐危种,占4．00％。     

顶空固相微萃取法分析毛药山茶花香气成分

采用顶空固相微萃取法提取了毛药山茶鲜花的香气成分,通过气相色谱-质谱联用技术(GC-MS)对香气成分进行了分析。共检测到50种香气成分,鉴定出19种,占总香气含量的71.72%。毛药山茶花香气成分主要为芳香族化合物、倍半萜、烷烃、烯烃和脂肪酸酯,其中倍半萜在总香气中的比例最高,为46.31%,其次为烷烃,为19.79%。     

移植胚胎数目对高龄不孕患者IVF-ET结局的影响

目的:探讨移植胚胎数目对高龄不孕患者IVF-ET结局的影响.方法:根据移植胚胎个数将年龄超过35岁的不孕患者338个周期分为单胚胎移植组(Ⅰ组),2个胚胎移植组(Ⅱ组),3个胚胎移植组(Ⅲ组).分析患者IVF治疗情况并按年龄分层比较三组患者的IVF-ET结局.结果:高龄不孕患者行IVF,随年龄增加,获卵数、优质胚胎率和临床妊娠率降低,流产率呈增高趋势.Ⅰ组的妊娠率9.43%,显著低于Ⅱ组(24.24%)和Ⅲ组(31.37%)(P＜0.05).对于40岁以下的患者,移植3个胚胎的妊娠率与移植2个胚胎差无异,但显著高于移植1个胚胎(P＜0.05).增加40岁以上患者移植胚胎的数目,妊娠率未出现有统计学意义的升高.三组的胚胎种植率分别为9.43%,12.12%和12.2%,无统计学差异.Ⅲ组中多胎率12.5%(6/48),其中35～36岁年龄段多胎率16.67%(5/30).结论:高龄不孕患者可移植的胚胎数目随年龄增加和获卵数目降低而降低.其中较年轻者(35～36岁年龄段),移植3个胚胎,对妊娠率提高无明显效果,但多胎发生显著增加.     

四种豆科作物的光合生理和生长发育对弱光的响应

为了确定豆科作物作为林果行间套种作物的适宜性, 于2014年通过田间试验和盆栽试验对4种豆科作物的耐阴能力及其光合生理进行了研究。测定全光和弱光处理(全光的48%)下豆科作物在初花期的叶片光合特征参数、光合色素含量与核酮糖-1,5-二磷酸羧化酶(RuBPCase)活性, 监测其生长发育对弱光的响应。结果表明: 弱光使供试作物的最大净光合速率、光饱和点、光补偿点、表观量子效率和暗呼吸速率不同程度地向耐阴植物变化; 弱光还使供试作物的净光合速率、气孔导度、蒸腾速率、瞬时水分利用效率和RuBPCase活性不同程度地下降, 而胞间CO₂浓度显著上升; 遮阴后, 乌豇豆(Vigna cylindrica)和绿豆(Vigna radiata)的叶绿素(Chl) a和Chl b含量显著增加, Chl a/b值显著降低, 大猪屎豆(Crotalaria assamica)和望江南(Senna occidentalis)的光合色素含量也有不同程度的变化; 弱光使供试作物茎变细, 侧枝数减少, 生物量和干物质积累效率降低, 根冠比降低, 根瘤量减少, 叶片变小变薄, 叶片数减少, 叶面积指数降低; 弱光胁迫下, 大猪屎豆不开花, 望江南只开花不结实, 而绿豆和乌豇豆开花数减少, 花期缩短, 种子产量显著降低。根据供试作物的光合特性和生长发育对弱光的响应, 得出它们的耐阴能力排序是: 乌豇豆>绿豆>望江南>大猪屎豆, 其中乌豇豆和绿豆适宜与林果套种, 而望江南和大猪屎豆不适宜套种。     

中国狭顶蚱属的研究及一新种记述(直翅目: 蚱总科)

记述中国狭顶蚱属11种, 包括采自云南的1新种, 即短背狭顶蚱Systolederus brachynotus sp. nov. 附有中国种类的检索表、分布和文献引证。 新种模式标本保存于陕西师范大学动物研究所标本室及西南林学院博物馆.     

Molecular cloning and characterization of <Emphasis Type="Italic">Izumo1</Emphasis> gene from sheep and cashmere goat reveal alternative splicing

We cloned the cDNA and genomic DNA encoding for Izumo1 of cashmere goat (Capra hircus) and sheep (Ovis aries). Analysis of 4.6 kb Izumo1 genomic sequences in sheep and goat revealed a canonical open reading frame (ORF) of 963 bp spliced by eight exons. Sheep and goat Izumo1 genes share >99% identity at both DNA and protein levels and are also highly homologous to the orthologues in cattle, mouse, rat and human. Extensive cloning and analysis of Izumo1 cDNA revealed three (del 69, del 182 and del 217) and two (del 69 and ins 30) alternative splicing isoforms in goat and sheep, respectively. All of the isoforms are derived from splicing at typical GT-AG sites leading to partial or complete truncation of the immunoglobulin (Ig)-like domain. Bioinformatics analysis showed that caprine and ovine Izumo1 proteins share similar structure with their murine orthologue. There are a signal peptide at the N-terminus (1–22 aa), a transmembrane domain at the C-terminus (302–319 aa), and an extracellular Ig-like region in the middle (161–252 aa) with a putative N-linked glycosylation site (N²⁰⁵-N-S). Alignment of Izumo1 protein sequences among 15 mammalian species displayed several highly conserved regions, including LDC and YRC motifs with cysteine residues for potential disulfide bridge formation, CPNKCG motif upstream of the Ig-like domain, GLTDYSFYRVW motif upstream of the putative N-linked glycosylation site, and a number of scattered cysteine residues. These distinctive features are very informative to pinpoint the important gene motifs and functions. The C-terminal regions, however, are more variable across species. Izumo1 cDNA sequences of goat, sheep, and cow were found to be largely homologous, and the molecular phylogenetic analysis is consistent with their morphological taxonomy. This implies the Izumo1 gene evolves from the same ancestor, and the mechanism of sperm–egg fusion in mammals may be under the same principle in which Izumo1 plays an important role.     

ABA信号转导途径中的MAPKs

脱落酸（ABA）是植物体内一种重要的激素分子,在调节植物生长发育和对环境适应的过程中发挥重要的信号作用。促分裂原活化蛋白激酶（MAPK）是一种广泛存在于真核生物中的信号转导途径,由环境胁迫、细胞因子、植物激素、生长因子等诱导,是植物细胞信号转导过程中的主要级联途径之一。已知许多蛋白激酶和蛋白磷酸酶参与了ABA信号途径,MAPKs作为ABA信号转导的下游组分发挥着重要的调节作用。本文就MAPK级联参与ABA信号转导途径的相关研究进展进行叙述,以便对MAPKs和ABA信号之间的交互作用（cross-talk）机制有更深入了解。     

湖北省两栖类一新纪录——大绿臭蛙

2009年8～9月及2010年7月,在湖北省宜昌市高家堰镇采集两栖类标本,其中,部分臭蛙标本被鉴定为大绿臭蛙(Odorrana graminea),属湖北省新纪录。要确定中国大绿臭蛙各居群的关系、澄清其分类问题,有必要进行适度的资源考察和深入的系统地理学研究。