一个叶片异常、根向重力性消失的拟南芥

分离并鉴定了一个拟南芥突变体alr1,其叶片向下卷曲且不对称发育,顶端优势增强,根向重力性消失,下胚轴缩短,寿限延长. 此外,alr1叶片呈现较高的超氧物歧化酶活性. 遗传分析表明alr1是隐性单基因突变. 采用简单序列长度多态性标记将alr1的突变位点定位于第一条染色体上,距标记nga111约7.89 cM.     

鱼腥藻PCC7120染色体MazEF同源基因对asr0757/alr0758的初步研究

鱼腥藻PCC7120染色体上的基因对asr0757/alr0758,经NCBI比对显示其与大肠杆菌中的毒素-抗毒素基因Maz EF具有较高的同源性,且具有毒素-抗毒素系统基因的保守遗传结构,为研究其是否属于Maz EF家族系统基因,构建同时含有asr0757和alr0758基因的双启动子选择性表达载体,先选择性诱导了该基因对的表达,再验证了其表达产物对细菌生长的影响.结果显示:成功诱导表达出了目的蛋白asr0757(13.5KD)和alr0758(17.5KD),当单独诱导asr0757基因表达时,细菌生长状况不受影响,单独诱导alr0758表达时细菌生长明显受到抑制,同时诱导asr0757和alr0758基因时细菌生长恢复正常,说明asr0757/alr0758构成具有生物功能的Maz EF家族系统基因对,具有毒性与抗毒性功能.     

用长臂光敏生物素标记的cDNA探针核酸斑点杂交检测马铃薯纺锤块茎类病毒

用长臂光敏生物素标记含有马铃薯纺锤块茎类病毒（Ｐｏｔａｔｏｓｐｉｎｄｌｅｔｕｂｅｒｖｉｒｏｉｄ，ＰＳＴＶｄ）双拷贝ｃＤＮＡ的重组质粒ｐＳＴ－Ｂ１４，制备成光敏生物素标记ｃＤＮＡ探针，用核酸斑点杂交检测感染ＰＳＴＶｄ的马铃薯叶片和块茎提取物均出现较强的阳性杂交信号，而健康马铃薯为阴性．试验结果表明：光敏生物素标记ｃＤＮＡ探针检测感染ＰＳＴＶｄ的马铃薯叶片汁液最高稀释度为１１２８     

鱼腥藻PCC7120染色体基因对asr0757/alr0758的表达优化及其鉴定

NCBI预测鱼腥藻PCC7120染色体上的基因对asr0757/alr0758可能构成一个毒素-抗毒素系统.为研究其是否属于毒素-抗毒素系统家族,分别构建这两个基因的表达载体.用1.0 mM IPTG诱导重组菌表达,优化表达条件,并对表达出的蛋白进行纯化与western blot检测.SDS-PAGE结果显示：asr0757与alr0758在37℃下诱导6 h后,均成功诱导表达出目的蛋白asr0757(13.5 KD)和alr0758(17.9 KD).抗毒素表达量较好,毒素alr0758表达量较少.通过设置诱导时间梯度和IPTG浓度梯度优化毒素基因表达条件,优化结果显示：毒素基因alr0758在28℃,IPTG浓度为0.4 mM,诱导10 h时有最大表达量.蛋白纯化与western blot结果证实诱导表达的蛋白为目的蛋白.     

应用Digoxigenin标记的cDNA探针检测香蕉束顶病毒

用非放射性的Ｄｉｇｏｘｉｇｅｎｉｎ标记的１１－ｄＵＴＰ取代３２Ｐ标记的ｄＡＴＰ或ｄＣＴＰ，标记克隆的ＢＢＴＶｃＤＮＡ－１０．５ｋｂｃＤＮＡ，制备成探针．通过核酸斑点杂交对粗提取的ＢＢＴＶ，ＢＢＴＶ－ＤＮＡ，感染ＢＢＴＶ的香蕉植物的拟茎，球茎处的组织，新生叶片以及成熟后的叶片进行了检测．结果表明：ＢＢＴＶｃＤＮＡ－１ｃＤＮＡ探针特异性强，不与ＣＭＶ—ＲＮＡ、无毒香蕉组培苗提取的核酸发生杂交反应；仅与粗提ＢＢＴＶ、ＢＢＴＶ－ＤＮＡ、ＢＢＴＶ侵染的香蕉组织的核酸提取物发生杂交反应．此探针灵敏度高，可检出含有ＢＢＴＶｃＤＮＡ－１０．５ｋｂ的质粒ＤＮＡ的最小量为１０ｐｇ；测定感病香蕉植株的拟茎汁液的最高稀释度可达１∶１２８，相当于０．４ｍｇ病蕉组织中的病毒含量．测定同一病株不同部位的结果表明，ＢＢＴＶ在植物体内的分布不均匀，拟茎处组织中病毒含量最高，球茎处的组织以及新生叶片中的病毒含量次之，成熟后的叶片中的病毒含量最低     

Detection of PSTVd with a New Nonradioactive Method──Digoxigenin Labeled cDNA Probe

使用非放射性标记ｄｉｇｏｘｉｇｅｎｉｎ标记的１１－ｄＵＴＰ取代３２Ｐ标记的ｄＡＴＰ或ｄＣＴＰ进行核酸斑点杂交检测马铃薯纺锤块茎类病毒（ＰＳＴＶｄ）．结果表明，ｄｉｇｏｘｉｇｅｎｉｎ标记具有灵敏度高，操作简单快捷，无放射性污染等优点．可检出含有ＰＳＴＶｄ的马铃薯叶片汁液最大稀释度及含有ＰＳＴＶｄ全序列的质粒ＤＮＡ的最小量分别为１３００和１０ｐｇ．同时该探针也用于检测了不同马铃薯品种及ＴＰＳ亲本中的ＰＳＴＶｄ感染情况，结果显示，其中一些品种及ＴＰＳ亲本已不同程度的被ＰＳＴＶｄ感染．     

鱼腥藻PCC7120质粒上毒素-抗毒素基因对alr9029/asr9028的初步研究

指出了大肠杆菌的毒素-抗毒素系统(TAs)能介导解离后致死机制维持细菌质粒的稳定性和参与环境胁迫诱导细菌生长抑制或死亡,在鱼腥藻PCC7120质粒上的基因对alr9029/asr9028具有与TA系统较高的同源性.为了证实该基因对属于TA系统,通过生物信息学分析了alr9029/asr9028的遗传结构,设计特异性引物,扩增得到大小为198 bp的asr9028和387 bp的alr9029.PCR产物经Bam H I和HindШ双酶切后被插入p MD18-T和p ET-30a中,依次构建克隆载体和表达载体.经SDS-PAGE电泳检测,含有His6标签的表达蛋白相对分子量分别为12.4k Da和19.2 k Da,且为可溶性蛋白.故初步认定asr9028为抗毒素基因,alr9029为毒素基因,二者共同构成一个TA系统.     

不同基质的水分亏缺对大花蕙兰生理生化特性的影响

测定了大花蕙兰（Cymbidium hybridum)在不同基质及基质含水量下的基质含水量（MWC），叶片含水量（LWC），叶水势（LWP）气孔导度，蒸腾速度，叶绿素含量，以及SOD，CAT，POD活性，MDA和PRO含量及叶片相对透性，结果表明，水藓（SP）基南的保水力高于花生壳掺沙（VPH：Vs=1:1)基质，SP基质临界水分是基质相对含水量的15．86％－12．32％，PH／S基质临界水分16．42％－12．29％，叶片含水量的阈值为87．41％－80．31％。气孔对水分亏缺反应的水势阈值是－0．70－1．35MPa。叶绿素含量对水分亏缺的反应不敏感，叶绿素的变化滞后于水势和叶片含水量，叶片外渗液相对电导率值在水分亏缺处理的后期急剧增加，SOD，CAT，POD活性和MDA及PRO含量变化与水分亏缺之间的变化复杂不宜作水分亏缺的指标，叶片含水量，叶水势可作为大花蕙兰水分亏缺的指标。     

压印光刻对准中阻蚀胶层的设计及优化

针对高速旋涂造成标记区阻蚀胶薄膜覆盖不对称和压印曝光造成标记区薄膜聚合的问题，利用压印光刻压印曝光固化脱模的工艺原理，提出了用压印预处理标记表面薄膜来优化阻蚀胶层厚度和形貌的工艺方法．该方法采用下压力约束薄膜，使阻蚀胶在标记区的栅格间重新分布，从而削弱了覆盖膜的不对称性，获得了相应的薄膜厚度．采用旋涂厚度为1．1μm的覆盖膜对压印预处理工艺方法进行了试验，发现下压力大于0．48MPa时，薄膜结构具有较好的对称性，下压力为1．12MPa时，对准信号的对比度达到最大．试验结果表明，压印预处理对于压印光刻系统具有较好的工艺适应性，利用该方法优化标记区的阻蚀胶层不仅能够有效削弱覆盖膜不对称和压印曝光的影响，而且对准精度可满足100nm压印光刻的要求．     

不同玉米群体灌浆期叶片生理特性的研究

在两种种植密度下，对三种株型玉米品种灌浆期叶片生理特性进行了研究．结果表明：耐密型品种中层叶片可溶性糖、可溶性蛋白和比叶重分别比对照提高20．1％、15．2％、8．1％；中间型品种的各指标也分别比对照提高17．8％，12．1％，11．8％；平展型品种的各指标分别比对照提高13．2％，11．4％，9．7％．因此，选择合理的种植密度，保证中层叶片发挥最佳生理功能是不同株型玉米品种达到高产的基础。     

Fine mapping and cloning of MT1,a novel allele of D10

Rice tillering is an important determinant for grain production.To investigate the mechanism of tillering,we characterized a multiple tillering mutant (mt1) identified from the japonica variety,Zhonghua 11,treated with EMS.This mutant exhibits advanced tillering development and dwarfed compared with wild-type plants.Genetic analysis and fine gene mapping indicated that the mt1 mutant was controlled by a recessive gene,residing on a 29-kb window on AP003376 of chromosome 1.One putative gene in this region,encoding a carotenoid cleavage dioxygenase 8 (CCD8),was allelic to D10.The mt1 mutant phenotype was complemented by introduction of wild-type MT1,and knockdown of MT1 in wild-type rice mimicked the mutant phenotype.Real-time PCR analysis indicated that the MT1 gene is expressed highly in stems and at a low level in axillary buds,panicles,leaves,and roots.In addition,MT1 expression is clearly under feedback regulation.     

Genetic analysis and gene mapping of a narrow leaf mutant in rice (Oryza sativa L.)

A narrow leaf mutant was obtained after T-DNA transformation conducted on a rice variety Zhonghua 11. Several abnormal morphological characteristics, including semi-dwarf, delayed flowering time, narrow and inward rolling leaves, and lower seed-setting, were observed. The rate of net photosynthesis (un-der saturate light) of flag leaves in the mutant was significantly lower than that of the wild type. More-over, the leaf transpiration rate and stomatal conductance in the mutant flag leaf were lower than tho...     

Isolation and characterization of rice lesion mimic mutants from a T-DNA tagged population

A rice ( Oryza sativa L. ssp. japonica cv. Nipponbare) T-DNA tagged population consisting of about 7000 individual lines was generated and screened for rice lesion mimic mutants in the T1 generation. Ten lines were found to develop spontaneous lesions in the absence of pathogen infection and displayed distinct lesion phenotypes. These mutants were tentatively designated as lm1 -lm10 (for lesion mimic), respectively. Lesion formation of lm mutants was developmentally regulated, and all the mutants showed stunted growth and reduced fertility. Genetic analysis demonstrated that all the mutations were recessive, and five partially fertile mutants (lm4-lm8) were derived from different loci. Mimic lesions occurring on the leaves of lm mutants resulted from cell death as revealed by trypan blue staining. Six of them ( lm3 -lm8 ) exhibited enhanced resistance to five bacterial blight isolates, indicating their wide-spectrum resistance to this pathogen. These results imply that some lesion mimic mutations of rice might be involved in disease resistance signaling pathways,and that isolation of these mutated genes may be useful for elucidating molecular mechanisms of plant disease resistance. Among the mutants, only one mutant, lm6, was preliminarily shown to cosegregate with the inserted T-DNA in its T1 generation, making it feasible to isolate the gene responsible for the phenotype of this mutant.     

谷子抽穗期突变体jt1242-14b的遗传分析和定位

为鉴定控制谷子抽穗的关键基因,通过甲基磺酸乙酯(ethyl methyl sulfonate,EMS)诱变谷子参考基因组测序品种豫谷1号,获得遗传稳定的谷子超早抽穗突变体jt1242-14b.与豫谷1号相比,jt1242-14b抽穗期明显提前,茎秆变细,叶片变窄、变短.遗传分析表明,突变性状受隐性单基因控制.以SSR41(父本)、jt1242-14b(母本)和F₂群体进行突变基因定位,结果表明,该基因位于第9号染色体,在分子标记In4746和In9-11之间的4 447 kb之内.进一步测序比对分析发现突变位点位于PHYB基因内部,因此,PHYB很可能是该早熟突变体的目标基因.本研究为谷子早抽穗基因克隆及PHYB基因功能研究提供材料基础.     

拟南芥温敏雄性不育突变体atms1的获得及表型分析

从甲基磺酸乙酯（ethylmethane sulfonate,EMS）化学诱变建立的野生型拟南芥（Col-0）突变体文库中筛选到1株突变体.在低温16 ℃时,该突变体的雄性育性与野生型没有显著差异,花粉染色呈现100%可育.随着培养环境温度的升高,突变体花粉育性逐渐下降,因此,该突变体为一温敏雄性不育突变体,并被命名为atms1（ambient temperature-sensory male sterility 1,即环境温度敏感雄性不育1）.花药切片结果显示,在23 ℃以下,该突变体花药各个发育时期的形态与野生型花药没有显著的差异;而27 ℃处理1周后的突变体花药呈现多种表型：同一朵花中各个花药的发育时期出现显著分化,花粉母细胞胼胝体单薄,绒毡层发育滞后于同时期的野生型花药.遗传分析确定,atms1的不育表型是由单个隐性核基因控制的.     

水稻矮化突变体G蛋白α亚基基因的结构和表达

利用γ-Co60辐射诱发水稻特光矮-2(Oryza sativa L.cv.TGA-2)产生变异,获得一种稳定遗传的新型水稻矮化突变体dwarf69.dwarf69和TGA-2及其杂交后代F1、F2、F3成熟期的株高数据表明矮化表型受一对隐性基因控制.进一步研究发现,虽然dwarf69和TGA-2的G蛋白α亚基基因(Rice G protein alpha-subunit,RGA)编码区核苷酸序列只有一个核苷酸的差异,但RGA在野生型TGA-2中的表达量明显高于在突变体dwarf69中的表达量.对矮化突变体dwarf69和野生型TGA-2的RGA基因5＇上游区的序列分析表明,dwarf69 RGA 5＇上游区比TGA-2RGA5＇上游区多出1076bp.首次报道水稻矮化突变体中的RGA5＇上游区序列与其野生种的RGA5＇上游区序列存在显著的差异.     

一个水稻白化致死突变体abl25鉴定及其基因定位

经Co60辐照的粳稻嘉花1号得到一个新的致死白化突变体albino lethal 25(abl25),该突变体从发芽至4叶期表现为白化苗,之后逐渐死亡.与野生型嘉花1号相比,abl25突变体的叶绿素含量和类胡萝卜素的含量大大降低,叶绿体结构不正常,说明其叶绿体发育受到严重阻碍,导致植物死亡.遗传分析表明:该突变体受一对隐性核基因(abl25)控制,进一步利用abl25与广占63S杂交的F2分离群体,将该突变体基因(abl25)定位于第2染色体上SSR标记RM424与Indel分子标记ID7330之间,随后利用新开发的分子标记和扩大群体将其定位在Indel分子标记ID9111和ID9261之间的150 kb内,发现abl25是一个新的水稻苗期白化致死基因.     

Genetic analysis and gene fine mapping of a rolling leaf mutant (<Emphasis Type="Italic">rl</Emphasis><Subscript><Emphasis Type="Italic">11(t)</Emphasis></Subscript>) in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

The exploration of new genes controlling rice leaf shape is an important foundation for rice functional genomics and plant archi-tecture improvement. In the present study, we identified a rolling leaf mutant from indica variety Yuefeng B, named rl_11(t), which exhibited reduced plant height, rolling and narrow leaves. Leaves in rl_11(t) mutant showed abnormal number and morphology of veins compared with those in wild type plants. In addition, rl_11(t) mutant was less sensitive to the inhibitory effect of auxin than the wild type. Genetic analysis suggested that the mutant was controlled by a single recessive gene. Gene Rl_11(t) was initially mapped between SSR markers RM6089 and RM124 on chromosome 4. Thirty-two new STS markers around the Rl_11(t) region were developed for fine mapping. A physical map encompassing the Rl_11(t) locus was constructed and the target gene was finally delimited to a 31.6 kb window between STS4-25 and STS4-26 on BAC AL606645. This provides useful information for cloning of Rl_11(t) gene.     

An Arabidopsis ctpA homologue is involved in the repair of photosystem II under high light

A T-DNA insertion mutant AtctpA1 was identified to study the physiological roles of a carboxyl-terminal processing protease (CtpA) homologue in Arabidopsis. Under normal growth conditions, disruption of AtctpA1 did not result in any apparent alterations in growth rate and thylakoid membrane protein components. However the mutant plants exhibited increased sensitivity to high irradiance. Degradation of PSII reaction center protein D1 was accelerated in the mutant during photoinhibition. These results demostrated that AtctpA1 was required for efficient repair of PSII in Arabidopsis under high irradiance.