南方根结线虫Col基因分子克隆及其VIGS效应分析

为了明确线虫角质层胶原蛋白基因(Col)与根结线虫病害的关系,利用从线虫基因组中预测的Col设计特异引物,克隆了南方根结线虫Meloidogyne incognitacol基因MiCol.该基因完整编码区长903bp,编码300个氨基酸.克隆的MiCol与预测的MiCol基因序列一致性高达99.67％,氨基酸序列一致性高达100％.利用病毒介导的基因沉默技术,将其导入番茄植株并接种南方根结线虫,60 d后,沉默载体pTV-MiColi处理番茄植株的根结数比空载体对照及清水对照分别减少49.4％和49.2％,表明MiCol基因沉默显著降低了南方根结线虫的侵染数量.     

褐飞虱海藻糖酶基因在表皮几丁质代谢中的调控作用

【目的】昆虫海藻糖酶能够调控几丁质代谢并控制蜕皮过程。本研究通过TRE表达被抑制后,检测褐飞虱(Nilaparvata lugens)蜕皮状况、几丁质含量及几丁质合成酶(chitin synthase,CHS)和几丁质酶(chitinase,Cht)基因表达情况,探究不同的海藻糖酶(trehalase,TRE)在褐飞虱表皮中对几丁质代谢的调控作用。【方法】采用RNAi技术,以实验室饲养种群褐飞虱为材料,通过向其体内注射双链RNA(dsRNA)分别抑制单个海藻糖酶基因或同时抑制多个海藻糖酶基因,注射48 h后通过Trizol法提取褐飞虱总RNA,反转录试剂盒合成第一链DNA后采用实时荧光定量PCR(qRT-PCR)技术检测该基因的表达情况,确定RNAi效果。氢氧化钾法测定48 h褐飞虱整体几丁质含量变化并对蜕皮困难虫体进行拍照;最后采用qRT-PCR检测褐飞虱CHS和Cht在mRNA水平上的相对表达量变化,分析TRE在调控几丁质代谢中的作用。【结果】与注射dsGFP相比较,其余各注射组褐飞虱整体几丁质含量显著下降,其中dsTRE1混合注射组与Validamycin注射组呈极显著下降,同时褐飞虱出现蜕皮困难等现象。qRT-PCR检测结果显示单个TRE的dsRNA注射后该基因的表达被抑制,但是部分TRE的表达有互补性上升。其中TRE1-2和TRE2在各注射组处理下表达均下降,dsTRE1s对TRE2的表达也有抑制效果,整体上dsTRE1混合注射组和海藻糖酶抑制剂Validamycin抑制效果明显;dsTRE注射组抑制CHS表达效果不明显,Validamycin能够显著降低CHS1和CHS1a在表皮中的表达,且2种dsTRE1注射后CHS1表达在上升,dsTRE1-2注射后表皮中的CHS1a的表达上升;Cht1和Cht8在dsTRE各注射组及Validamycin处理中表达下降或显著下降,dsTRE1-1注射后Cht2和Cht5表达显著上升;dsTRE1-2注射后Cht1、Cht6和Cht8表达下降,Cht2和Cht4表达显著上升;dsTRE2处理组中Cht1、Cht8和Cht10表达下降而Cht9表达显著上升;dsTRE1s注射后,Cht1和Cht5表达显著下降,而Cht9表达显著上升;Validamycin注射组中10个几丁质酶基因表达都显著或者极显著下降。【结论】TRE能够通过调控褐飞虱几丁质代谢途径来控制几丁质的合成,结果可为开展和筛选有效的海藻糖酶抑制剂控制褐飞虱等害虫提供理论依据。     

昆虫生长调节剂对东亚飞蝗表皮和脑神经分泌细胞的影响(Ⅱ)

通过光学显微镜及电子显微镜观察，综合分析了昆虫生长调节剂卡死克对东亚飞蝗表皮与脑的显微及亚显微形态结构的影响。结果表明，处理后的若虫表皮由于真皮细胞结构被破坏导致内表皮变薄、板层结构消失，而且真皮细胞层与内表皮层分离，细胞质内小泡变大而分布不均，核染色质凝结成为小颗粒且分布不匀。脑神经分泌细胞受药物影响数量明显减少，结构松散，胞间空泡变大，引起轴突变形。经透射电子显微镜检查发现，脑神经分泌细胞的轴突与胞体分离并膨大变形。线粒体结构发生改变，膜与内嵴消失。另外，轴浆运输中的神经分泌颗粒明显减少。     

水果裂果研究进展

综述了国内外对鲜食水果裂果的研究进展，从果实的形态解剖特性、环境因子、栽培措施、矿质营养元素与平衡等方面阐述了裂果发生的机理。认为表皮细胞大、果实角质层薄易于裂果；果实生长前期，土壤含水量不足，果皮发育受到影响，果实发育后期，久旱逢雨，果肉细胞迅速增大可造成裂果；缺钙、钾等矿质元素，易产生裂果。提出了预防裂果的几项措施。     

干旱胁迫对3种苹果属植物叶片解剖结构、微形态特征及叶绿体超微结构的影响

采用树脂包埋块半薄/超薄切片技术,通过光镜（LM）、扫描电镜（SEM）和透射电镜（TEM）方法,研究了轻度、中度和严重干旱胁迫对楸子（Malus prunifolia）、新疆野苹果（M. sieversii）和平邑甜茶（M. hupehensis）叶片组织解剖结构、表皮微形态特征（气孔密度、大小及角质层厚度）及叶绿体超微结构的影响。光镜观察结果表明,与对照相比,干旱胁迫条件下3种苹果属植物叶片厚度、栅栏组织厚度及叶肉组织结构紧密度（CTR）都显著减小（P＜0.05）,而海绵组织厚度与叶肉组织结构疏松度（SR）均显著增加（P＜0.05）。扫描电镜观察结果显示,3种苹果属植物幼叶气孔密度在干旱胁迫下显著增大（P＜0.05）,而气孔宽度、开张比及其开张度明显下降。透射电镜观察结果表明,在干旱胁迫下,楸子和新疆野苹果上下角质层厚度逐渐增加,而平邑甜茶的随干旱胁迫程度增加呈先增后减的变化;在轻度和中度水分胁迫下,叶绿体膨胀变形,淀粉粒变小消失,基粒片层排列松散减少,类囊体腔扩大;在严重胁迫条件下,叶绿体膨胀近圆形,叶绿体膜破裂,类囊体严重泡化开始解体。与平邑甜茶相比,严重水分胁迫下楸子和新疆野苹果叶绿体超微结构损伤较小,能较好地保持细胞结构的完整性。     

Characterization and genetic mapping of eceriferum-ym (cer-ym), a cutin deficient barley mutant with impaired leaf water retention capacity

The cuticle covers the aerial parts of land plants, where it serves many important functions, including water retention. Here, a recessive cuticle mutant, eceriferum-ym (cer-ym), of Hordeum vulgare L. (barley) showed abnormally glossy spikes, sheaths, and leaves. The cer-ym mutant plant detached from its root system was hypersensitive to desiccation treatment compared with wild type plants, and detached leaves of mutant lost 41.8% of their initial weight after 1 h of dehydration under laboratory conditions, while that of the wild type plants lost only 7.1%. Stomata function was not affected by the mutation, but the mutant leaves showed increased cuticular permeability to water, suggesting a defective leaf cuticle, which was confirmed by toluidine blue staining. The mutant leaves showed a substantial reduction in the amounts of the major cutin monomers and a slight increase in the main wax component, suggesting that the enhanced cuticle permeability was a consequence of cutin deficiency. cer-ym was mapped within a 0.8 cM interval between EST marker {"type":"entrez-nucleotide","attrs":{"text":"AK370363","term_id":"326489160","term_text":"AK370363"}}AK370363 and {"type":"entrez-nucleotide","attrs":{"text":"AK251484","term_id":"151420132","term_text":"AK251484"}}AK251484, a pericentromeric region on chromosome 4H. The results indicate that the desiccation sensitivity of cer-ym is caused by a defect in leaf cutin, and that cer-ym is located in a chromosome 4H pericentromeric region.     

Hull to caryopsis adhesion and grain skinning in malting barley: Identification of key growth stages in the adhesion process

Strong adhesion between the hull and the caryopsis is essential for barley to be of good malting quality. Poor hull adhesion, a condition known as grain skinning, is undesirable for malting and downstream processes. At present, the processes mediating hull adhesion during grain development are poorly understood. The barley cultivar Chariot was grown in greenhouse conditions and grain development was recorded at defined growth stages to examine the timing of hull adhesion. Initiation of adhesion was first observed when caryopsis fresh weight and volume were approaching their maximum at 19 days after anthesis, during early dough. Hull adhesion was complete by 27 days after anthesis, or soft dough. Sections of developing grains were observed using light and transmission electron microscopy to examine a lipid-rich cementing layer believed to be responsible for adhesion between the hull and the pericarp. Evidence for a lipid-rich cementing material was supported by the observation that neither pectinase nor cellulase effected hull loosening. Grain growth, the presence of globular material originating from the pericarp and an electron dense material in the cementing layer are discussed in relation to hull adhesion. Grain skinning could be caused by poor adherence of cuticular material or inadequate fusion between cuticles.     

植物角质层结构组成、生物学功能及分离方法研究进展

角质层包括角质和蜡质,是覆盖在花、叶和非木质茎等植物地上部分器官的一层疏水性脂类物质,具有限制植物体内水分过度散失、抵御紫外辐射、防止病虫害入侵等功能,在植物生长发育和适应生物与非生物逆境过程中起到重要保护作用。角质层结构以及化学组成是影响其生物学功能的主要原因,具有十分重要的研究价值。综述了植物角质层的结构组成、生物学功能及其常用分离方法,并对已有研究中存在的问题进行了探讨,以期为今后角质层生理作用及其生物学功能方面研究提供理论参考。     

The physical action of three diatomaceous earths against the cuticle of the flour mite Acarus siro L. (Acari: Acaridae)

Experiments examined the accepted modes of action of the desiccant dust, diatomaceous earth (DE), against the flour mite, Acarus siro (L.) (Astigmata). Adult mites were exposed to three DE products for periods of 3, 18 and 72 h under conditions designed to allow partial desiccation of the mites without causing mortality. After exposure, the DE dust particles were washed off the mite bodies, and both the DE and the mites were examined for presence of cuticular hydrocarbons by gas chromatography-mass spectroscopy (GC-MS) analysis. GC-MS identified seven major cuticular lipids of chain length C(13)--C(26) that may have a role in the waterproofing of A. siro. After 18 h exposure, n-tridecane and several different long-chain fatty acid ethyl esters were detected on one of the DE products. After 72 h, n-tridecane was detected on all three DE products. Mite samples retained after removal of the DEs were examined by microscopy. Tentative evidence was observed by conventional low-power microscopy that might indicate uniform removal of the epicuticle. However, a detailed examination by scanning electron microscopy showed no signs of abrasion.     

棉铃虫对氰戊菊酯的抗性机理研究

以羧酸酯酶抑制剂磷酸三苯酯（ＴＰＰ）和多功能氧化酶抑制剂增效醚（ＰＢＯ）以及￣（１４）Ｃ－氰戊菊酯为材料，选择对氰戊菊酯具有不同抗性程度的棉铃虫自然种群为试虫，研究其抗性机理。结果表明：棉铃虫对氰戊菊酯的抗性与其体内酯酶活性无关，而与多功能氧化酶活性直接相关；同时，表皮对氰戊菊酯的渗透性降低也是棉铃虫对氰戊菊酯产生抗性的强化因子。