玉米S型细胞质雄性不育与恢复花粉中基因表达差异分析

以近等基因系S-Mo17Rf3Rf3和S-Mo17rf3rf3为材料,通过抑制消减杂交对S(Rf3)和S(rf3)花粉中差异表达的基因进行了研究.结果表明,玉米(Zea mays L.)S(Rf3)和S(rf3)花粉中存在与信号传导、膜系统形成、花粉的成熟以及抗细胞衰老等细胞和生理活动相关的基因表达的差异,但没有发现参与糖代谢、淀粉合成及其转运相关基因的表达差异.O-乙酰半乳糖胺转移酶(O-linked GlcNAc transferase,OGT)基因在Rf3花粉中表达累积.依据OGT基因的功能及其在玉米不同育性花粉中的表达模式,推测OGT受糖类物质诱导表达并与S(Rf3)配子的育性恢复有关.这一假说还有待进一步实验证实.     

Identification and characterisation of ten glutathione S-transferase genes from oriental migratory locust, Locusta migratoria manilensis (Meyen)

BACKGROUND: Synthetic pyrethroids are the primary insecticides that are widely used for controlling Locusta migratoria manilensis (Meyen), a major pest in eastern and southern Asia and the Pacific region. In this paper, ten cDNAs encoding glutathione S‐transferases (GSTs) were sequenced and characterised in L. migratoria manilensis. The effects of deltamethrin on the ten GST gene expressions were studied. RESULTS: Phylogenetic analysis revealed nine GSTs in three different classes, including seven in sigma, one in delta and one in theta. The remaining GST (LmGSTu1) was unclassified. RT‐PCR analysis showed that most GST genes were expressed in all tissues examined, including the foregut, midgut, gastric caecum, hindgut, Malpighian tubules, fat bodies, muscles, spermaries and ovaries, except that LmGSTs2, LmGSTs4, LmGSTs7 and LmGSTu1 were expressed in several tissues. LmGSTu1 appeared to be the only gene whose expressions could not be detected in eggs. Real‐time quantitative PCR showed that deltamethrin at 0.08 and/or 0.12 µg mL^?1 increased almost all ten GST gene expressions in third‐instar nymph locusts. However, deltamethrin at 0.16 and/or 0.2 µg mL^?1 decreased the expressions of LmGSTd1, LmGSTs1, LmGSTs5 and LmGSTs6. CONCLUSION: The increases in GST gene expressions after deltamethrin exposure in L. migratoria manilensis might result in its elevating tolerance to other insecticides and xenobiotics. Copyright © 2011 Society of Chemical Industry     

采后荔枝果皮中谷胱甘肽转移酶基因的表达与酶活分析

为探明荔枝谷胱甘肽转移酶基因(Lc GST)的表达与果皮褐变之间的关系,在荔枝c DNA芯片中获得了荔枝Lc GST全长c DNA序列(ABR15777)。该序列全长913 bp,5′-UTR长53 bp,3′-UTR长215 bp,含一个645 bp的完整开放阅读框,编码含214个氨基酸残基的多肽。该氨基酸残基序列与沙梨等物种的谷胱甘肽转移酶蛋白相似性较高。基因表达分析表明,Lc GST在常温储存条件下基因的最大表达量出现在24 h,在保湿储存条件下,Lc GST的最大表达量出现在48 h。GST酶活性测定结果表明,在常温储存条件下酶活性的最大值出现在24 h,在保湿储存条件下酶活性的最大值出现在48 h。说明Lc GST在荔枝果皮褐化过程中起重要作用。     

鞘氨醇单胞菌TP-3中基因spsK的克隆及生物信息学分析

以自杀性质粒pUT携带的mini—Tn5转座子对菌株TP-3进行转座诱变,从转座突变库中筛选到不能合成产物鞘氨醇胶ss的突变株,进而采用Tn5外向扩增与LP—RAPD／fN结合的方法,得到糖基转移酶编码基因spsK的801bp序列全长。生物信息学分析表明,其氨基酸序列与迪特胶以及S88合成途径中的糖基转移酶同源性最高,达47％;SpsK蛋白具有典型的G—loop和DXD保守模式,属于糖基转移酶的GT—A家族。     

The enzymatic incorporation of isopentenyl pyrophosphate into polyisoprene in rubber particles from Parthenium argentatum Gray

Studies have indicated the presence of both a de novo biosynthesis of new polyisoprene chains and the elongation of pre-existing rubber-PP chains in rubber particles from Ficus elastica Roxb. and small rubber particles from Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg. In this paper, we have isolated rubber particles from the cortical parenchyma of Parthenium argentatum Gray with an adsorbed isopentenyl pyrophosphate isomerase that was competent to form polyisoprene to determine the presence of de novo biosynthesis of polyisoprene and the elongation of pre-existing rubber-PP. The gel filtrated rubber particles were supplied saturating concentrations of [¹⁴C]-isopentenyl pyrophosphate for 1 h and the resulting concentrations of [¹⁴C]-polyisoprene were isolated and analyzed with a Waters 150C Gel Permeation Chromatograph. The mol wt distribution of the [¹⁴C]-polyisoprene ranged from 10³ to 10⁶ Da with no formation of high mol wt chains equal to the polyisoprene in the mol wt distribution of natural rubber from P. argentatum. The mol wt distribution of [¹⁴C]-polyisoprene following 1 h of incubation of the reaction mixture was similar to the mol wt distribution formed by the bound rubber transferase in washed rubber particles of H. brasiliensis and the time-dependent formation of polyisoprene by washed rubber particles from P. argentatum. The data support the conclusion that the washed rubber particles from P. argentatum contain a bound rubber transferase that initiates the formation of new chains of polyisoprene from the dimethylallyl pyrophosphate initiator generated from the added isopentenyl pyrophosphate isomerase followed by the extensive polymerization of isopentenyl pyrophosphate to form a monomodal rubber polymer. There was no evidence in these washed rubber particles of a chain elongation of pre-existing rubber-PP.     

茶树类黄酮3-O-葡萄糖基转移酶基因的克隆和表达分析

以茶树叶片为材料,结合同源克隆方法和RACE技术,克隆了1条UFGT基因,命名为CsUFGT。该基因cDNA全长为1526bp,ORF长1380bp,编码459个氨基酸,推测等电点5.96,推测分子量为49.486kDa。该基因编码的蛋白质与葡萄UFGT（P51094.2）的一致性为59%,相似性为75%,其C-端含有植物UGT家族成员特有PSPG基序。荧光实时定量PCR分析表明,该基因在茶树根茎叶中均表达,在第4叶表达量最高,根和茎中表达量较低。     

The response of ACCase-resistant Phalaris paradoxa populations involves two different target site mutations

Phalaris paradoxa (awned canary-grass) is an aggressive annual winter weed in wheat and other arable crops that is controlled mainly by ACCase-inhibiting herbicides: cyclohexanediones (DIMs), aryloxyphenoxypropionates (FOPs) and phenylpyrazolines (DENs, e.g. pinoxaden). The selection pressure imposed on the weed populations by repeated use of these herbicides has resulted in the evolution of increased numbers of ACCase-resistant populations of P. paradoxa in Israel and other countries. Two populations, Revadim (RV) and Mishmar Ha'emek (MH) that were exposed to differing weed and crop management tactics were investigated. Both populations were highly resistant to all FOPs, pinoxaden and cycloxydim, but responded differently to some DIMs. RV plants exhibited much higher resistance to tralkoxydim than MH plants, while showing similar low levels of resistance to tepraloxydim and clethodim. Both populations were equally susceptible to graminicides with other modes of action. The mutations responsible for the observed resistance were identified using PCR-RFLP and by sequencing the carboxyl transferase domain of the chloroplastic ACCase gene. RV plants possess a substitution of Asp₂₀₇₈ to Gly, whereas in MH population a mixture of Ile₂₀₄₁ to Asn or Asp₂₀₇₈ to Gly was found. Our study demonstrates that lack of herbicide and crop rotation may result in the evolution of diverse target site mutations and differential response of the whole plant to ACCase inhibitors.     

黑尾叶蝉精氨酸激酶和一个谷胱甘肽S转移酶基因的克隆和发育表达特性研究

黑尾叶蝉（Nephotettix cincticeps）是一种能传播病毒的水稻害虫,对水稻生产有着巨大的威胁。本文在黑尾叶蝉中克隆得到了一个精氨酸激酶基因（NcAK）和一个delta类型的谷胱甘肽-S-转移酶基因（NcGST）,并对两个基因进行了序列分析和表达特性检测。结果表明,NcAK包含的开放阅读框长度为1 068 bp,编码一个含356个氨基酸的蛋白。进化研究表明该蛋白序列与玻璃翅叶蝉（Homalodisca vitripennis）的精氨酸激酶的序列亲缘关系最近。Real time结果表明NcAK在黑尾叶蝉的雄成虫中表达量高于在卵、1龄若虫、5龄若虫和雌成虫中的表达量。NcGST的开放阅读框由651个碱基组成,编码一个包含217氨基酸的蛋白,进化研究表明该蛋白与美国牧草盲蝽(Lygus lineolaris)GSTs编码蛋白亲缘关系最近。表达量检测表明NcGST在5龄若虫和雌雄成虫中的表达量要高于在卵和1龄的表达量。