拟南芥株型突变体zpr1的性状特征与基因鉴定分析

对本研究室经T-DNA插入法获得的拟南芥株型突变株系——隐性突变体zpr1植株进行植物学性状调查和遗传分析,并对该突变基因进行鉴定、表达定位和调控元件分析。结果显示:(1)性状分析表明,与野生型拟南芥Ws-2相比,突变体zpr1的茎生叶分枝数量增加,茎生叶分枝发生于拟南芥顶端花序部位;野生型拟南芥茎生叶为披针形,而突变体zpr1没有出现分枝的茎生叶呈倒卵形,出现分枝的茎生叶呈披针型;突变体zpr1的主花序高度、株高、分枝高度和分枝长度都高于野生型,且分枝数多于野生型。(2)利用质粒挽救和反向PCR法(IPCR)确定了ZPR1基因突变发生位置是该基因起始密码子上游426bp处,证明T-DNA插入破坏了ZPR1基因的启动子区域,导致该基因在拟南芥内不能正常表达。(3)基因转录调控区域的顺式作用元件分析发现在ZPR1基因的转录调控区有多个与植物激素相关的调控元件,还有与光周期调节相关的调控元件。(4)亚细胞定位发现,ZPR1基因在所有细胞中的细胞膜中表达,而在部分细胞的细胞膜、细胞质和细胞核中均有表达。研究表明,ZPR1基因的表达对植物株型发育有重要的调控作用,该基因的表达水平受植物激素和光照的调节,最终导致了植物株型的变化。     

S3307对秋大豆株型和产量的影响

秋大豆始花期和盛花期喷施５０￣１００ｍｇ·Ｌ＾－１Ｓ３３０７后，植株矮化，茎秆增粗，复叶小而厚、叶柄粗短、叶绿素含量增加，上部复叶功能期延长，主茎结荚部降低，荚数，粒数和百粒重增加，产量提高。     

一个高粱直立叶突变体的表型鉴定和遗传分析

直立叶是构建合理株型和培育密植化栽培品种的重要指标之一.本研究利用甲基磺酸乙酯(EMS)诱变高粱BTX623,获得一株可以稳定遗传的直立叶突变体,暂命名el(erect leaf).该突变体叶片从6叶期开始出现直立性状,直至整个生育期叶片均呈直立状态.抽穗期突变体el植株倒1叶至倒7叶各节位叶长极显著缩短,叶片宽度也显...     

甜瓜突变体库的构建及M2群体表型变异的研究

利用8种不同浓度的甲基磺酸乙酯（EMS）,4种不同的浸种时间,处理甜瓜品系“3-2-2”种子,根据M1代植株发芽率,筛选出适宜的诱变剂量为浓度1.2%,诱变时间为24 h。采用这种方法构建了含有67个M1家系及相应自交M2代种子的甜瓜突变体库。对M1代群体541个单株的表型变异进行了全生育期初步调查,总的表型变异频率达71.53%。对M2代群体603个单株的节间长度、主蔓粗度、叶片长度、叶片宽度、叶柄长度、叶柄粗度共6个表型性状进行形态学调查表明:除节间长度外,其它5个性状和野生型相比均差异显著;不同性状的变异系数不同,叶柄长度的变异系数最大,达15.37%,节间长度的变异系数最小,为7.10%;在M2代中,编号为25的家系叶片出现了黄色和绿色的性状分离。     

糜子EMS突变体库构建和突变体筛选北大核心CSCD

糜子(Panicum miliaceum L.)具有抗旱、耐瘠、适应性广、生育期短等特点,是我国北方地区的杂粮作物。糜子高产品种不耐水肥、易倒伏,锄草、间苗费时费工的问题严重影响着农民对糜子生产的积极性和收入。EMS(甲基磺酸乙酯)化学诱变方法成本低,操作简单,诱变率高,是作物育种的重要方法。本试验选用糜子品种伊选大红糜进行EMS化学诱变而构建突变体库,对获得的2333个M2材料进行突变频率和全生育期表型多样性等特征的分析。结果显示,所构建的糜子突变体库材料变异类型非常丰富,共发现104个形态性状突变株系,突变频率为4.5%,包括叶色、叶型、株高、生育期、育性、穗型、种皮颜色等性状,该突变体库的构建将为糜子功能基因组学研究和育种提供丰富的突变体资源和新型种质。     

S3307对秋大豆株型和产量的影响(简报)

秋大豆始施期和盛花期喷施50～100mg·L－1S3307后，植株矮化、茎秆增粗，复叶小而厚、叶柄粗短、叶色转绿、叶绿素含量增加，上部复叶功能期延长，主茎结英部位降低，荚数、粒数和百粒重增加，产量提高。     

EMS诱变玉米突变体苗期生理生化特性研究

实验分别选取四种白色突变玉米白1、白2、白3、白4为材料,以诱变的非突变玉米为对照。分析了玉米的代谢特性和抗性。结果表明突变体的代谢及抗性没有非突变体强,但我们也发现,在四种白色突变体中,白2表现突出。白2幼苗根系活力,叶绿素含量,POD、SOD活性,脯氨酸含量均比对照高,而加MDA含量比对照低,说明在四种突变体玉米中白2苗期表现出对环境的适应能力提高,且抗性增强。     

高粱EMS诱变及突变体筛选、鉴定

突变率和突变类型是突变体表型筛选和构建饱和突变体库的重要依据。采用不同时间和不同浓度甲基磺酸乙酯(EMS)处理高粱品种BTx623的种子,突变率和突变类型差异较大。突变类型可分为叶色、叶形、穗型、育性及生育期等,变异类型较丰富。根据处理后种子出苗率、结实率和突变率的情况,最终确定20 h+EMS 0.2%为最佳的诱变处理时间和浓度。但构建饱和突变体库,建议采用多浓度多时间处理方式。     

小麦矮秆圆粒突变体的鉴定与分析

小麦的子粒形态性状和株高与小麦的产量密切相关,是育种的重要选择目标性状。本研究通过对小麦品种偃展1号(YZ1)EMS突变体W98的农艺性状的调查与分析,发现W98的株高只有24 cm,而野生型YZ1的株高是73 cm。突变体株高的变异是由每个节间长度变短造成的,而非节间数目减少所致。相关分析表明矮秆与圆粒性状呈显著相关。利用高秆长粒的墨西哥品种10th12与突变体W98配制杂交组合,获得1544个F2∶3单株(株系),通过对分离群体的遗传分析,发现圆粒性状是由1对不完全显性基因控制的。赤霉素(GA)与油菜素内酯(BR)激素敏感性试验表明:野生型和突变体都对GA处理不敏感;不同浓度BR的展叶试验表明野生型对BR不敏感,而突变体W98对BR敏感。     

Isolation and characterisation of an antifolate insensitive (afi1) mutant of Arabidopsis thaliana

Antifolates can impair the synthesis and/or function of folates in living organisms. Mechanisms of resistance or tolerance to antifolates have been mainly described in plants using the drug methotrexate. In this work, the antifolate trimethoprim (TMP) was used with the aim of revealing a novel mechanism of resistance. EMS mutagenised seeds from Arabidopsis were screened to isolate individuals insensitive to TMP. Genetic analysis revealed a homozygous recessive mutation that segregates with the phenotype of tolerance to 50 μm TMP. Mapping analysis localised the mutation at the end of the short arm of chromosome 3. Preliminary characterisation demonstrated up‐regulation of several genes from the folate biosynthetic pathway in the TMP insensitive mutant, and a slight increase in total folate content in the mutant as compared with the Col‐0 control. Moreover, sequence analysis of the DHFR (dihydrofolate reductase) genes, which encode a known target for resistance to antifolates, did not reveal any changes. This study is the first report of a stable mutant insensitive (afi1) to the antifolate trimethoprim in plants, and suggests the existence of a novel mechanism of resistance to antifolates.     

A new mutant class of soybean lacks urease in leaves but not in leaf-derived callus or in roots

Summary We reported earlier the recovery of two classes of soybean urease mutants in soybean (Glycine max L. Merr. cv. Williams). Class I mutants lack the embryo-specific urease while class II mutants lack the activities of both urease isozymes, the embryo-specific and the ubiquitous urease, the latter found in all tissues examined. We report here the recovery of a true-breeding mutant, aj3, which represents the third phenotypic class: normal levels of embryo-specific urease and little or no ubiquitous urease. Unlike class II mutant plants which lack urease in all tissue, aj3 lacks urease activity only in leaves (ca. 2% normal activity); its roots have near normal urease activity. Callus derived from leaves of aj3 has 14% to 40% the urease activity of Williams 82 callus. This partial reduction in urease activity in aj3 callus is sufficient to reduce growth with urea as sole nitrogen source and to confer resistance to 50 mM urea added to callus maintenance medium. Leaves of aj3 produce more than 40 times the urease antigen expected from their urease activity. The aj3 trait is due to a single recessive lesion which is not allelic with lesions at theEu2, Eu3 (class II) orEu1 (class I) loci. We designate the aj3 genotype aseu4/eu4.     

Inheritance of high oleic acid content in the seed oil of soybean mutant M23

A mutant line, M23, of soybean [Glycine max (L.) Merr.] was found to have two fold increases in oleic acid content in the seed oil compared with the original variety, Bay. Our objective was to determine the inheritance of the high oleic acid content in this mutant. Reciprocal crosses were made between M23 and Bay. There were no maternal and cytoplasmic effects for oleic acid content. The F₁ seeds and F₁ plants were significantly different from either parents or the midparent value, indicating partial dominance of oleic acid content in these crosses. The oleic acid content segregated in the F₂ seeds and F₂ plants in a trimodal pattern with normal, intermediate and high classes, satisfactorily fitting a 121 ratio. The seeds of a backcross between M23 and F₁ segregated into intermediate and high classes in a ratio of 11. These results indicated that oleic acid content was controlled by two alleles at a single locus with a partial dominant effect. Thus, the allele in M23 was designated ol and the genotypes of M23 and Bay were determined to be olol and 0l0l, respectively. The oleic acid contents of the F₂ seeds and F₂ plants were inversely related with the linoleic acid content which segregated in a trimodal pattern with normal, intermediate and low classes in a 121 ratio. Thus, it was assumed that the low linoleic acid content in M23 was also controlled by the ol alleles. Because a diet with high oleic acid content reduces the content of low density lipoprotein cholesterol in blood plasma, the mutant allele, ol, would be useful in improving soybean cultivars for high oleic acid content.     

裸燕麦EMS突变体库筛选与分析

燕麦是重要的粮饲兼用作物,构建燕麦EMS突变体库对燕麦功能基因组学研究和遗传改良有重要意义。本试验利用化学诱变剂甲基磺酸乙酯(EMS,ethyl methane sulfonate)处理燕麦品种花早2号,获得了4083株M1材料;对其中2000个单株种植了M2株行,进行全生育期调查,鉴定其表型变化;对2份黄化苗突变材料种植了M3家系,进行相关突变性状的稳定性验证。结果表明,燕麦经EMS处理后代变异巨大,在M2发现表型突变材料196份,变异率为9.8%,变异类型非常丰富,包括幼苗习性、叶片性状、分蘖、株高、穗部形态及成熟期等突变株系。M3证实突变的黄化苗特性可以稳定遗传。本研究建立了燕麦EMS诱变体系,获得的燕麦变异类型丰富,为燕麦功能基因组学研究和燕麦遗传改良奠定了材料基础。     

The genetic interaction between non-nodulation and supernodulation in soybean: an example of developmental epistasis

Summary The interaction between three non-nodulation mutants (nod49, nod772 and nod139) and a supernodulation mutant (nts382) of soybean was studied by analysing the progeny from crosses between these mutants. Previously it had been shown that the non-nodulation mutants arose from single mutation events and that nod49 and nod772 are allelic, whereas nod139 represents another gene required for nodulation. Analysis of progeny from crosses between nts382 and the wild type showed that this mutant also arose from a single mutation. Complementation tests demonstrated that the mutation responsible for supernodulation in nts382 is not allelic to either of these non-nodulation characters, and that it segregates independently. Progeny were identified that were homozygous for both supernodulation and non-nodulation, and these plants were incapable of nodulation. Thus, non-nodulation is epistatic over supernodulation and this is discussed in terms of the developmental blockage in the two mutant types. The identification and confirmation of these double mutants of the supernodulation and non-nodulation mutations are described. Although the non-nodulation mutations behave as recessive characters in a wild-type background, these mutations are incompletely dominant in a genetic background homozygous for supernodulation. The significance of these results to the understanding of nodule ontogeny is discussed.     

田间大豆植株N2O通量的测定及光照的影响

采用封闭式箱法 ,在田间自然状况下对大豆植株N2 O通量进行了测定 .结果表明 ,在主要生育期内 ,大豆植株N2 O通量有 2个释放高峰 ,分别位于苗期和开花结荚期 .大豆植株N2 O通量的昼间变化模式基本上为上午有 1个释放高峰 ,而下午有一个释放低谷 .施肥和对照小区N2 O平均通量分别为 2 .2 7和 1 .2 8μgN2 Om- 2 ·h- 1 .在较强的光照条件下( 1 0 4 lx数量级 ) ,大豆植株N2 O通量较低 ,甚至可吸收大气中的N2 O ,而在较弱光照条件下( 1 0 3～ 1 0 2 lx数量级 ) ,大豆植株N2 O通量较高 .     

Enhanced transpiration rate in the high pigment 1 tomato mutant and its physiological significance

Tomato high pigment (hp) mutants represent an interesting horticultural resource due to their enhanced accumulation of carotenoids, flavonoids and vitamin C. Since hp mutants are known for their exaggerated light responses, the molecules accumulated are likely to be antioxidants, recruited to deal with light and others stresses. Further phenotypes displayed by hp mutations are reduced growth and an apparent disturbance in water loss. Here, we examined the impact of the hp1 mutation and its near isogenic line cv Micro-Tom (MT) on stomatal conductance (gs), transpiration (E), CO(2) assimilation (A) and water use efficiency (WUE). Detached hp1 leaves lost water more rapidly than control leaves, but this behaviour was reversed by exogenous abscisic acid (ABA), indicating the ability of hp1 to respond to this hormone. Although attached hp1 leaves had enhanced gs, E and A compared to control leaves, genotypic differences were lost when water was withheld. Both instantaneous leaf-level WUE and long-term whole plant WUE did not differ between hp1 and MT. Our results indicate a link between exaggerated light response and water loss in hp1, which has important implications for the use of this mutant in both basic and horticultural research.     

田间大豆植株N2O通量的测定及光照的影响

采用封闭式箱法,在田间自然状况下对大豆植株N₂O通量进行了测定.结果表明,在主要生育期内,大豆植株N₂O通量有2个释放高峰,分别位于苗期和开花结荚期.大豆植株N₂O通量的昼间变化模式基本上为上午有1个释放高峰,而下午有一个释放低谷.施肥和对照小区N₂O平均通量分别为2.27和1.28μgN₂Om^-2·h^-1.在较强的光照条件下(10⁴lx数量级),大豆植株N₂O通量较低,甚至可吸收大气中的N₂O,而在较弱光照条件下(10³～10²lx数量级),大豆植株N₂O通量较高.     

传统大豆发酵食品中大豆异黄酮的生理保健机能的研究进展

大豆异黄酮属于黄酮类化合物,是一类具有重要生物活性的化合物,在大豆和传统大豆发酵食品中含量丰富。近年来研究发现大豆异黄酮在预防癌症、骨质疏松症、心血管疾病和改善妇女更年期综合症等方面具有广泛的生理活性,因此引起了国内外学者的广泛关注。大豆异黄酮的研究,不仅为功能性大豆制品的开发提供理论基础,也为人们合理的膳食提供参考。综述近年来国内外对大豆异黄酮生理保健机能的研究进展。     

Aerobic and anaerobic alcohol dehydrogenases in Escherichia coli

Abstract Mutants unable to use ethanol for carbon and energy were counterselected from an ethanolutilizing mutant of Escherichia coli K12 derepressed for alcohol dehydrogenase (ADH). Mutants of one class were devoid of ADH activity under anaerobic conditions but exhibited aerobic activities comparable to those of wild-type E. coli. Mutants of a second class exhibited ADH activity levels intermediate between those of the wild-type and derepressed parent. Immunological studies showed that mutants of the former class synthesized far less ADH protein than did the derepressed parent while mutants of the latter class synthesized about the same amount. The ADH mutations in both classes were located within the previously described adh region which contains the structural gene for the activity that is derepressed in the parent. An Eth⁻ adh-lac fusion mutant with an insertion in the structural gene was also isolated and characterized. It exhibited no ADH activity under anaerobic conditions and wild-type levels under aerobic conditions. These data are consistent with the existence in E. coli of distinct aerobic and anaerobic ADH enzymes and a derepression of the anaerobic but not the aerobic enzyme in the ethanol utilizing strain.