伪应答调控蛋白在植物光周期调控途径中的作用

开花是植物由营养生长向生殖生长转变的重要过程,光周期是调控这一过程的关键环境因素之一。在高等植物开花的光周期途径中,生物钟处于关键位置,在调控植物开花中发挥重要作用,它能对输入信号进行振荡处理,并传递给下游基因,同时保持自身节律性,从而调控开花。伪应答调控蛋白(PRRs)作为生物钟中央振荡器的重要组成部分,主要作用是调控下游基因的表达,参与昼夜节律的调节。本文综述了PRRs家族的结构特征、表达规律、成员之间的调控关系及其在光周期调控网络中的作用,为进一步研究PRRs基因家族的分子功能及互作提供了一定的理论参考。     

二穗短柄草BdGI基因表达及其蛋白互作分析

光周期是调控植物开花的主要途径之一,GI在光周期途径中是控制生理节律和开花的关键因子。为探索二穗短柄草（Brachypodiam distachyon）BdGI基因的表达模式和蛋白互作关系,本研究通过实时荧光定量PCR(qRT-PCR)技术分析BdGI基因在不同光照条件下和长日照下不同生长发育阶段的表达情况;运用酵母双杂交初步筛选出互作蛋白BdZTL,并用双分子荧光互补法（BiFC）和免疫共沉淀法（CoImmunoprecipitation）进行验证。qRT-PCR分析结果表明,BdGI基因在不同光照下和长日照下不同生长发育阶段的表达情况不同,且都保持一定的昼夜节律,并且受到光周期的调控;利用酵母双杂交检测到GI与ZTL蛋白存在互作关系,双分子荧光互补与免疫共沉淀检测结果验证了两者互作关系的真实性。综上所述,BdGI的表达受光周期调控,具有昼夜节律性,在光周期诱导二穗短柄草开花的过程中也具备一定的调控作用。本研究结果为GI基因的功能研究奠定了理论基础。     

蓝光受体ZTLs家族调控植物光周期途径研究进展

光周期途径是调控植物开花的重要途径之一,在长期的进化过程中,植物对光周期途径中的光诱导形成了极其精细和完善的光感受系统。植物接收光信号主要通过光感受系统中的光受体(photoreceptor)实现。ZTLs家族是一类蓝光受体蛋白,泛素化调节植物体内蛋白质的降解,在光信号向生物钟输入和调节下游开花基因表达中发挥重要作用。本文对不同植物中ZTLs家族蛋白的结构、功能等研究进行了综述与展望,为阐明ZTLs家族通过光周期途径调控开花的机制提供了一定的理论依据。     

MADS-box基因控制植物成花的分子机理

植物花器官的发育和开花是植物生殖发育中最重要的过程,植物在长期的进化过程中产生了春化（低温）途径、自主途径、光周期途径以及不依赖于光温环境条件的赤霉素信号途径来适应多变的环境和调控植物开花过程。本文综述了模式植物拟南芥中由LEAFY（LFY）、CONSTANS（CO）、FLOWERING LOCUSC（FLC）、FLOW ERING LOCUS T（FT）和SUPPRESSOR OF OVEREXPRESSION OF CO1（SOC1）等基因构成的双子叶植物响应光温条件变化的开花调控网络;以及大麦、小麦中由VERNALIZATION1（VRN1）、VRN2、ODD-SOC2（OS2）和拟南芥CO、FT同源基因构成的禾本科植物开花调控网络。其中最重要的是转录调控因子MADS-box基因FLC、SOC1、VRN1和OS2,并发现组蛋白的乙酰化/脱乙酰化,赖氨酸的甲基化/脱甲基化在调控FLC、VRN1染色质活性状态及基因表达,从而产生开花控制的机理。这些研究发现将有助于对具有重要经济价值的单双子叶植物,通过生物技术手段改良其品种特性以应对非生物逆境,特别是低温胁迫的指导。     

高羊茅FaGI基因在拟南芥中异源表达及蛋白互作分析

为探究高羊茅FaGI基因的生物学功能,本研究利用酵母双杂交、双分子荧光互补和免疫共沉淀探究与FaGI互作的蛋白;通过农杆菌介导法将过表达载体p1300-FaGI遗传转化拟南芥,获得转FaGI基因拟南芥株系,以拟南芥野生型Col-0、过表达FaGI基因株系和gi突变体为材料进行转录组学测序并观察其开花表型。结果表明,利用酵母双杂交方法筛选出与FaGI互作的FaCO蛋白,并通过双分子荧光互补和免疫共沉淀证明了FaGI和FaCO在体内和体外存在互作关系;过表达FaGI基因拟南芥植株的开花时间比野生型Col-0提前约1.24 d;将FaGI-OE、gi与野生型比对,分别筛选出1 963和92个差异表达基因（DEGs）,与野生型植株相比,过表达FaGI基因株系的差异基因富集在与生长发育、光周期途径、激素合成和信号传导、碳代谢等相关生物过程和代谢通路。综上,FaGI影响光周期途径相关基因的表达,在长日照条件下过表达FaGI基因促进了拟南芥开花,同时该基因的功能具有多样性与复杂性,可作为高羊茅调控分子育种的目标基因。本研究结果为揭示FaGI基因的功能及其调控网络奠定了基础。     

粉菠萝FVE同源基因的克隆及表达分析

FWE是植物自主开花途径中的关键基因,主要通过抑制FLC的表达来调控花发育过程。本研究利用粉菠萝似echmeafasciata）茎尖组织转录组序列数据,通过RACE技术克隆获得了粉菠萝中n,E同源基因A毋yE的cDNA全长序列。该序列全长为1672bp,开放阅读框为1404bp,编码由468个氨基酸残基组成的蛋白,该蛋白序列中含有6个保守的WD重复区域。氨基酸序列比对结果表明,4椰E基因编码的氨基酸序列与其它物种中WE的同源序列具有较高的相似性。qRT—PCR（实时荧光定量PCR）分析结果显示,粉菠萝中A椰E基因对外源乙烯的刺激产生了应答。在采用乙烯利灌心处理不同时间的过程中,发现A删E基因的转录水平均在处理后1d时达到最大,推测A椰E可能参与乙烯信号反应,该基因在粉菠萝自主开花途径中的调节作用可能受乙烯影响。     

试管开花生物技术研究概况

本文对试管开花生物技术的研究进展进行了简要综述,着重介绍了植物生长调节剂、光周期、温度等影响因子对植物花的发育过程的调节。试管开花技术还有一些方面有待于进一步研究,而高速发展的生物技术为试管开花提供了广阔的市场前景。     

小麦光周期基因TaCO9-1A的克隆、功能标记开发及其与冬春性关系的研究

光周期是植物从营养生长转为生殖生长的重要影响因子,CO(constans)基因在模式植物拟南芥(Arabidopsis thaliana)的光周期途径中起重要作用。本研究利用同源克隆技术从普通小麦(Triticum aestivum L.)宁春4号中克隆了CO同源基因Ta CO9-1A(Gen Bank登录号:KM236233)的g DNA(genomic DNA)及c DNA(complementary DNA)。Ta CO9-1A的全长编码区(coding sequences,CDS)为876 bp,编码291个氨基酸,含有CO-like蛋白家族典型的CCT结构域,但不含B-box结构域;系统进化分析表明,Ta CO9-1A蛋白与水稻(Oryza sativa L.)Ghd7及大麦(Hordeum vulgare L.)Hv CO9位于同一分支;蛋白质空间结构分析表明,其CCT结构域的NF-YA2区域较为保守;Ta CO9-1A原核表达蛋白分子量为31 k D,与预测结果一致;实时荧光定量PCR结果显示,Ta CO9-1A在普通小麦抽穗期的根、茎、叶及幼穗均有表达,但根部表达量较低,相对表达量依次为叶茎幼穗根。比较该基因在冬春性不同品种中的核酸序列发现,冬性品种第二外显子存在6个碱基的缺失,针对该差异开发了分子标记,在25份冬春性不同的小麦品种中扩增出511和517 bp两种带型,分别与这些品种的冬春性及在杨凌地区两年的抽穗及开花时间早晚显著相关。本研究结果表明,Ta CO9-1A在小麦春化作用和光周期途径中扮演着重要角色,为研究小麦光周期途径和春化作用途径提供了基础资料,有助于揭示Ta CO9-1A调控小麦冬春性及成熟期的分子机理。     

植物诱导抗虫基因研究进展

植物的诱导抗虫基因可分为3类，即防御基因、防御物质合成基因和信号途径基因，综述了这3类基因的种类及其功能。植物诱导抗虫基因除了受昆虫和损伤诱导外，还受植物激素茉莉酮酸酯、水杨酸、阿司匹林、脱落酸和乙烯，以及其它信号物质的调控，这些信号物质的调控途径组成了复杂的植物防御的信号传输网络。植物诱导抗虫基因的研究将为害虫防治提供新的途径。     

雷竹VRN1同源基因克隆及功能分析

拟南芥VERNALIZATION 1(VRN1)基因是一个介导春化途径,调控开花时间的基因。为了研究竹类植物中VRN1同源基因的功能,采用同源克隆技术从雷竹中分离到一个VRN1同源基因,将其命名为PvVRN1。序列分析表明,该基因编码245个氨基酸,与小麦、水稻中VRN1同源基因相似性分别为86.56%和88.98%。实时荧光定量PCR结果表明,PvVRN1在开花雷竹中的表达量高于未开花雷竹;在开花雷竹中,PvVRN1在秆、花、叶芽中表达量相对较高。亚细胞定位分析表明,PvVRN1蛋白质主要存在细胞核中。PvVRN1在拟南芥中的过表达使转基因植株矮小,花瓣和萼片比野生型短,但是在开花时间上与野生型无差异,表明PvVRN1基因可能参与雷竹花形态建成以及其它发育过程。本研究结果可为阐明竹子开花机制提供科学依据。     

Variation in flowering time in sorghum core collection and mapping of QTLs controlling flowering time by association analysis

A wide range of variation in flowering time was observed within a diversity research set of 107 sorghum accessions ranging from 56 to 133 days. Accessions were classified into early medium and late flowering groups. 45 accessions were grown under three different environments of photoperiod (11, 12 and 15 h). Sorghum accessions gradually responded to the decreasing of day-length. The 12 h of photoperiod could be considered as a threshold above which day-length delays the flowering time in sorghum. Association analysis was performed to identify the QTLs controlling flowering time and photoperiod sensitivity using 107 accessions of sorghum grown under natural condition and 45 accessions grown under controlled conditions. Four QTLs controlling flowering time were detected under natural condition of day-length at threshold 2.5 using K model. A total of seven flowering time loci were detected under controlled conditions of day-length. One QTL controlling photoperiod sensitivity was detected on chromosome 1 and one QTL controlling photoperiod insensitivity was detected on chromosome 4.     

光周期对切花菊生长及开花的调控

以‘红面’切花菊（Hongmian）为试材，设置6组光周期处理，分别为昼/夜7h/17h（记为Ph7）、8h/16h（Ph8）、9h/15h（Ph9）、10h/14h（Ph10）、11h/13h（Ph11），以长日照（13~14h）处理为对照CK，研究不同光周期对其生长及开花的影响。记录不同处理现蕾、破蕾、初花、盛花的时间和叶片数，测定分析不同发育期叶片可溶性总糖、蔗糖和蛋白含量，并于不同处理达盛花期时测定其花、茎鲜重以及干物质在不同器官的分配率，以阐明不同光周期对‘红面’菊初花期和出花品质的调控作用，为不同发育期的菊花栽培提出具有针对性的补光建议。结果表明：（1）叶片数随光照时间的增加而增加，并以CK的增加速率最大，Ph11次之，Ph7最小。（2）‘红面’切花菊的花期明显受光照时长的影响，Ph10处理下的菊花从苗期−现蕾、成花耗时均最短，Ph11从初花−花瓣全展开的盛花期耗时最短，Ph7、Ph8和CK花期严重滞后。（3）不同发育期叶片可溶性糖、蛋白含量均呈“M”形变化趋势，两次峰值分别出现在花芽分化期和开花前。可溶性总糖含量以CK最大，Ph11次之；作为可感知光周期信号的信使分子蔗糖，以及可溶性蛋白含量均以Ph10最大。（4）花鲜重以Ph11最大，促花效果显著。因此生产上将秋菊开花时间提前的同时，为保证切花质量，苗期应接受大于11h/d的长日照条件，使菊花苗进行充分的营养生长而不过早诱发花芽分化，以10h/d的光照条件进行诱花处理，花蕾形成且开始成花显色后，花芽分化已不可逆，再将其置于11h/d的光照条件下花瓣可最快全部展开。     

PVX介导拟南芥Flowering locus T诱导烟草开花研究

为研究拟南芥Flowering locus T（FT ）基因在开花诱导过程中的重要生物功能,本研究采用RT-PCR方法,从拟南芥野生型（WS）中得到全长FT序列,采用Potato Virus X（ PVX ）野生型病毒构建载体,将全长FT基因连接到PVX第5个阅读框架即Coat Protein（ CP ）编码序列之前,经体外转录成PVX-FT病毒RNA,人工感染短日照烟草Maryland mommath,成功诱导短日照烟草在长日照条件下开花。     

Geographical patterns of diversity in pearl millet germplasm from Yemen

Yemen differs considerably from many other countries in its extreme variation in elevation. A set of 229 pearl millet germplasm accessions collected from diverse elevations of Yemen was characterized for 12 morpho-agronomic characteristics at ICRISAT, Patancheru, India. Analysis of variance revealed highly significant differences (P < 0.001) among elevational zones for flowering, plant height and seed weight when evaluated in the post-rainy season and for panicle length and thickness when evaluated in the rainy season. The differential performance of accessions for flowering and plant height during the rainy and post-rainy seasons at ICRISAT, Patancheru reflected the photoperiod and temperature sensitivity of the accessions. Shannon-Weaver diversity indices indicated high diversity from low elevations for flowering and plant height. The results of the present study imply that environmental factors such as elevation, temperature and rainfall are the important determinants of variation patterns of pearl millet in Yemen and pearl millet germplasm from high elevations of Yemen is a good source for early maturity, cold tolerance, short plant height and large seeds.     

The effect of photoperiod‐induced flowering on the nutrient content of pea shoots 1

The effects of the photoperiodic induction of flowering on nutrient uptake were studied using genetic lines of pea (Pisum sativum). Nitrogen, K, P, Mn, Fe, and Cu concentrations in the plants were higher in short days (SD) (vegetative), Mg concentrations were higher in long days (LD) (reproductive). Ca, B, and Zn levels appeared to be unrelated to light regimes or flower induction. Plants grown in LD had higher total uptake of most elements, because of substantially higher dry matter production. Low light treatments that stimulated flowering had less effect on nutrient composition than LD (full light). The nutrient concentrations of a photoperiod‐insensitive line were less affected by light regime, and total uptake appeared to be primarily dependent on photosynthate production. It was concluded that the induction of flowering does not impose special demands on nutrient uptake, and that, although photoperiod affected nutrient content, the effect was indirect.     

Photoperiodic effect on flowering and seed development in quinoa (Chenopodium quinoa Willd.)

Abstract

Sensitivity to photoperiod in quinoa (Chenopodium quinoa Willd.) was studied under controlled conditions to enhance crop adaptation to environments outside its centre of origin. Two varieties, a traditional variety from Bolivia (Real), which will not mature under Danish conditions, and an early maturing variety (Q52), developed for Danish climatic conditions, were used in this reciprocal transfer experiment. Plants were moved from a short daylength of 10 h (SD) to a long daylength of 18 h (LD) and vice versa at set intervals from sowing to 100 days after sowing (DAS). A reaction of LD in time to flowering was observed only in the Bolivian variety Real. Under SD both varieties flowered after 39 DAS. For Real the LD regime resulted in a moderate increase in time to flowering to 44 DAS. The non-sensitive, juvenile period in Real was estimated to be approximately 16 days. In Q52 a moderate increase in the number of leaves was formed on the main stem after flowering at LD, which indicates that some daylength sensitivity remains. The most striking difference occurred during seed filling, when going from SD to LD. In Q52 the time from the end of flowering to maturity increased from 39 to 52 days. Under SD, Real had a seed-filling period similar to Q52, but at LD Real remained with green leaves during seed filling. Hard seed was observed in the still green perigonium 57 days after end of flowering. At this moment re-shooting occurred from the inflorescence, and seed maturity was not reached at the termination of the experiment at 150 DAS. This study shows that flower induction is not a major problem for adaptation of quinoa to North European conditions but that a very strong, daylength sensitive, stay green reaction is the main cause of the late maturity of South American introductions.     

中国野生稻的遗传学研究

本文对中国野生稻的遗传性、性状遗传研究、花器、开花习性、打破种子休眠、提高种子发芽力的研究、抗病虫性鉴定、抗逆性鉴定、品质鉴定、细胞遗传学特征、遗传标记和光周期反应等方面作了简要的综述。