光敏胞质雄性不育小麦育性转换期叶片中NAD激酶和NADP磷酸酶？…

由光敏感胞质雄性不育小麦育性转换敏感期叶片中ＮＡＤ激酶和ＮＡＤＰ磷酸酶的活性变化表明：在长光照处理下,光敏胞质雄性不育小麦白皮２２４在光敏感期,叶片中的ＮＡＤ激酶总活性和钙调素非依赖性ＮＡＤ激酶活性高于短日照处理。钙调素依赖ＮＡＤ激酶则相反,在短日照条件下,其活性明显地高于ＬＤ处理。     

光敏核雄性不育水稻叶绿体的光合特性

本文报告了在育性转换敏感期光周期处理对湖北光敏核雄性不育水稻最新全展叶叶绿体光合特性的影响。结果表明：与短日照相比,长日照处理的农垦５８ｓ水稻叶绿体只有较低的ＰＳⅡ光化活性和ＰＳⅡ原初光能转化效率,其ＰＳⅡ和全链的电子传递速率低,叶绿体中叶绿素ｂ的含量较少,叶绿素ａ／ｂ值比短日照处理的高化活性普遍下降,这可能是导致农垦５８ｓ败育的初始原因之一。     

光敏核雄性不育水稻叶绿体的光合特性

本文报告了在育性转换敏感期光周期处理对湖北光敏核雄性不育水稻（农垦５８ｓ）最新全展叶叶绿体光合特性的影响。结果表明：与短日照（ＳＤ）相比,长日照（ＬＤ）处理的农垦５８ｓ水稻叶绿体只有较低的ＰＳⅡ光化活性和ＰＳⅡ原初光能转化效率,其ＰＳⅡ和全链的电子传递速率低,叶绿体中叶绿素ｂ的含量较少,叶绿素ａ／ｂ值比短日照处理的高约１０％。长日照处理使农垦５８ｓ叶绿体的光化活性普遍下降,这可能是导致农垦５８ｓ败育的初始原因之一。     

光周期对光敏核不育水稻光敏色素A含量及其mRNA丰度的影响

光敏核不育水稻(农垦58S)是我国特有的水稻(Oryza sativa L.)种质材料,光敏色素是光周期诱导其育性转变的受体。报道了育性转换敏感期间的光周期处理对农垦58S及对照“农垦58”叶片中光敏色素A(Phy A)含量及其mRNA丰度的影响。在10个光周期处理的最后一个暗期结束前,收获每株水稻的上部两片叶,用酶联免疫吸附测定法测定Phy A。和长日照(LD)相比,短日照(SD)处理导致农垦58SPhy A相对含量增加38.5％;而“农垦58”只增加18.5％。显然,在较长的暗期中,农垦58S中Phy A的积累比对照快。在水稻幼苗中也得出相似的结果。以光敏色素A基因(phy A)的特异性片段RPA3作探针,用RNA斑点杂交的方法对叶片中Phy A mRNA丰度进行分析的结果表明,光周期处理5d和10d时,两品种水稻的Phy A mRNA丰度都是SD处理的比LD的高,而且SD下农垦58S Phy A mRNA的丰度均比“农垦58”的高。这些结果表明,甲基化水平较低的农垦58S phy A可能比“农垦58”的phy A更活跃地表达。另外,在育性转换敏感期每日主光期结束时(EOD)进行10次短暂的远红光(FR)照射。结果表明,农垦58S植株抽穗和开花期比SD处理推迟2d,而花粉败育率、种子结实率却无变化。暗示农垦58S开花和育性转变过程的光周期反应可能不同。     

光周期对光敏胞质不育小麦花药发育过程中Ca^2＋分布的影响

运用焦锑酸钾沉淀法,研究了不同光照条件下光敏胞质不育小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ Ｌ．）花药发育过程中Ｃａ＾２＋的分布。短日照条件下,小孢子形成和花粉发育过程中胞内Ｃａ＾２＋在数量、分布上有变化;小孢子表面逐渐积累Ｃａ＾２＋,至成熟花粉表面覆盖一层Ｃａ＾２＋,胞质Ｃａ＾２＋较少;药隔和药壁组织通过抽外体或共质体途径运输Ｃａ＾２＋供给花粉的发育;长日照条件下,花粉败育发生在不同时期,早期     

农垦58s育性转换与吲哚乙酸氧化酶和过氧化物酶的关系

本文报道了农垦58s和农垦58幼穗发育期长短日下吲哚乙酸氧化酶和过氧化物酶的活性变化。结果表明:58s LD叶片中吲哚乙酸氧化酶活性从花粉母细胞形成期至花粉内容物充实期显著低于58s SD,与游离IAA的积累密切相关,可能影响花粉育性;但过氧化物酶的活性在上述时期显著高于58s SD,与游离IAA的积累无关,其作用尚不清楚。58s LD幼穗及花药中两酶活性在减数分裂期和花粉内容物充实期均较58s SD高,与同期幼穗及花药中游离IAA的亏缺有一定联系,从而可能在一定程度上影响花粉育性。对照农垦58叶片和幼穗及花药中两酶活性变化都不呈现上述现象。     

K、V、T型小麦细胞质雄性不育系叶绿体DNA的SSR分析及RuBP羧化酶活性比较

为了探讨小麦细胞质雄性不育(CMS)与叶绿体DNA(cpDNA)的关系,揭示CMS机理。以2套K、V、T型同核异质不育系(A)及其保持系(B)‘太911289’和‘冀5418’、育性恢复的F_1和各自的质供体粘果山羊草(Aegilops kotschyi)、偏凸山羊草(Aegilops ventricosa)、提莫菲维小麦(Triticum timopheevii)为试验材料,利用cpSSR引物对小麦cpDNA进行比较分析,筛选出代表不同胞质不育系的引物,探讨CMS与叶绿体的关系;同时测定由叶绿体DNA与核DNA共同编码的RuBP羧化酶的活性,为小麦K、V、T雄性不育类型的应用提供理论依据。结果表明:(1)K型、V型、T型不育系与保持系的cpDNA之间均呈现多态性,且不同的细胞质之间存在特异片段,这从DNA水平上提供了3类不育系胞质来源不同的证据,并分别找到5对和7对可以鉴定V型和T型不育系的特异引物。(2)除K型‘冀5418’与其胞质供体的cpDNA出现差异外,不育系与其胞质供体的cpDNA没有差异,而且不育系与其育性恢复的F_1代cpSSR扩增片段之间也没有差异,很好地遗传了其母本性状。(3)在起身期和开花期,不仅2套不育系的RuBP羧化酶活性显著高于保持系,且在不育系与恢复系杂交的F_1中,随着育性的恢复其RuBP羧化酶活性高于保持系而低于各自不育系;而在拔节期的不育系与保持系之间、不育系之间、以及F_1代与不育系和保持系之间的RuBP酶活性大小没有显著差异。这可能与拔节期主要是营养生长有关系。     

免疫测定光敏核不育水稻中光敏色素I含量

光敏核不育水稻（农垦58S）是中国水稻研究中的一个重要发现,水稻杂交育种上有巨大潜力。研究表明：农垦58S的雄性不育性受光周期调控,光敏色素是育性转变过程中光周期反应的光受体。然而,鉴于高等植物中存在至少两种不同的光敏色素分子,并且它们同时存在水稻中,人们对调节农垦58S雄性不育过程的光敏色素分子种类及作用方式仍然不清楚。本文采用酶联免疫吸附测定法（ELISA）,比较了不同光周期下农垦58S和对照品种农垦58叶片（光周期感受器官）中光敏色素（phyA）的含量。从农垦58S的二次技梗原基分化期开始,进行10天的光周期处理,一组为短日照（SD）,另一组为长日照（LD）。在第10个暗期结束前,于暗绿光下收获每株水稻的最上部两片新展叶,立即保存在液氮中。样品在研钵中磨成液氮粉,然后加入提取液（含50mmol/LTris-HCI和0．2mol／L巯基乙醇,pH8．5）匀浆。粗提液经0．5％聚乙烯亚胺（PEI）沉淀一,上清液供ELISA分析。以燕麦phyA的多克隆隆抗体、单克隆抗体分别作ELISA的一抗和检测抗体。供ELISA分析。以燕麦phyA的多克隆抗体、单克隆抗体分别作ELISA的一抗和检测抗体。采用ELISA可以专一性地检测水稻phyA(Table1)。几次独立的实验说明,光周期处理对phyA含量有较大的影响。要相同的光周期下,农垦58S的phyA在较长时间暗期中的合成速度明显比农垦58快,这证实了前人的推测,即农垦58S甲基化程度较低的phyA基因的表达可能比农垦59更活跃。许多研究指出,pohyA含量的高低必然影响有关的生理过程。两种基因型相同的大麦品种对光周期、远红光（FR）敏感性的不同反应正是phyA含量差异所致。因此,SD下叶片积累较多的phA可能是农垦58S花粉育性恢复所必需的。另外,在农垦58S育性转变敏感期内每天的光周期结束时（EOD）进行短暂（15分钟）的FR照射实验,以推测光敏色素(PhyB)在育性转变中的作用,因为EODFR反应由phyB介导。10次EODFR处理后,农垦58S的抽穗、开花期均比SD对照相应地推迟2天。这与穗、开花（LD效应）,其花粉败育、种了结实率却没有变化（图1）,说明开花与花粉育性的调控机制有所不同。从上述结果我们认为,可能是phyA,而不是pohyB参与光周期诱导的农垦58s花粉育性转变过程,并且phyA可能通过其含量的变化起调节作用;phyB与水稻的抽穗、开花等现象有关。农垦58S可能通过其含量的变化起调节作用;phyB与水稻的抽穗、开花等现象有关。农垦58s控制花粉正常发育的phyA信号传导链可能存在某些缺陷,从而导致对光周期的敏感性增加,SD下积累较多的phyA则可以弥补这些缺陷。     

光照强度对温光敏细胞核雄性不育小麦育性的影响

以具有低温不育、高温可育特性的温光敏细胞核雄性不育小麦C412S和C404S为材料,以其回交转育亲本、育性正常的C412和C404为对照,用人工气候箱研究了光照强度对温光敏细胞核雄性不育小麦育性表达的影响。结果表明,在低温条件下(日温8℃/夜温6℃),C412S和C404S在不同光照强度(160μmol/m2.s和300μmol/m.2s)下自交结实率都为0,表现为完全不育。在较高温度条件下(日温18℃/夜温14℃),从花粉母细胞形成期到开花期的光照处理,C412S在160μmol/m.2s弱光照下的自交结实率仅为5.4%,表现为高不育,在300μmol/m2.s较强光照下的自交结实率高达65.0%,表现为高度可育;而另一不育系C404S在2种光照强度下的自交结实率分别为69.9%和73.2%,都达到了高度可育水平。表明光照强度对温光敏细胞核雄性不育小麦的雄性育性表达具有重要影响,但不同材料对光照强度的响应程度有所差异。     

大豆开花基因GmCO和GmFT的克隆及表达

为了研究大豆光周期反应是否受开花基因CO(CONSTANS)和FT(FLOWERING LOCUS T)调控,采用同源序列法从大豆中分离了CO和FT的同源物GmCO和GmFT.GmCO和GmFT分别编码151和109个氨基酸,与水稻和拟南芥中相关蛋白的氨基酸序列同源性达到70%以上.通过RT-PCR分析GmCO和GmFT在短日照(short daylength,SD)、自然光照(natural light,NL)和长日照(long daylength,LD)处理大豆不同发育阶段叶片中的表达发现,GmCO在LD处理大豆早期发育的叶片中高丰度表达,GmFT在SD和NL处理大豆开花时期的叶片中高丰度表达.上述结果表明,GmCO和GmFT的表达与大豆开花时间及光照长度密切相关,且GmCO抑制GmFT的表达.     

Effect of Photoperiod Treatments on Phytochrome a Levels and Its mRNA Abundance in Photoperiod-Sensitive Genic Male-Sterile Rice Mutant and the Wild Type

The effect of photoperiod treatments on phytochrome A (Phy A) level and its mRNA abundance in the leaves of a photoperiod-sensitive genic male-sterile mutant (Nongken 58S) and its wild type ("Nongken 58') of Oryza sativa L. was investigated. The top two leaves of each rice shoot were harvested at the end of the last dark phase of 10 cycles during photoperiod-sensitive stage for fertility alteration of the mutant. Phy A was measured by a sandwich enzyme-linked immunosorbent assay (ELISA) using rabbit polyclonal and mouse monoclonal antibodies. Compared with longday (LD) treatment,short day (SD) resulted in 38.5% increase of relative Phy A content in the mutant, only 18.5% increase in the wild type. In an extended darkness (25 h), the accumulation of Phy A also appeared to be more rapid in the mutant seedlings than in its wild type. RNA dot blot analyses with RPA3 (a cDNA clone of rice Phy A) as a probe showed:the abundances of Phy A mRNA in top leaves of Nongken 58S and "Nongken 58" were obviously higher in SD than those in ID at the end of dark phase of 5 d and 10 d photoperiod treatments. Moreover, under SD Phy A mRNA contents in Nongken 58S were more than those in "Nongken 58" during the whole photoperi- od-sensitive stage for fertility alteration. In addition, after 10 cycles of end-of-day far-red irradiations (EOD FR), the heading and flowering date of the mutant was delayed for 2 d. However, EOD FR had little or no effect on male fertility of the mutant.     

氮素形态对烤烟光合特性影响的研究

1996～1997年连续二年进行了固定氮素用量,改变铵态、硝态氮肥的施用比例试验,对烤烟的一些光合生理特性进行了研究。试验结果表明,在烤烟生长前、中期,增施铵态氮施用比例,烤烟的叶绿素含量增加,但达100％铵态氮时,叶绿素含量反而下降,低于施用50％和75％铵态氮的处理;在烤烟生长后期．功能叶片叶绿素含量基本上与施用铵态氮比例高低—致,以100％铵态氮处理的叶绿素含量最高。另外增加铵态氮施用比例,烤烟功能叶片的希尔反应活性及光合磷酸化活性有所提高,但P/O比值基本不变。从叶绿素诱导荧光动力学特征参数及比值情况来看：增加铵态氮施用比例,Fm和Fv值升高;几种荧光参数的比值如Fd/Fs、Fv/Fo、Fv/Fm比值有所上升,但均以25％硝态氮+75％铵态氮的处理最高;并且其烤后烟叶的产量最高、品质最好。     

核酸代谢抑制剂对水稻光敏核不育性的影响

在稻穗分化的二次枝梗期后,观察比较了叶片喷施核酸代谢抑制剂5-FU对水稻光敏核不育性及幼穗发育的影响,结果表明：长日照下,5-FU在使农垦58S穗长缩短、颖花数减少的同时,却使其抽穗提前,可育性得到一定程度的恢复;5-FU处理还使农垦58的抽穗被完全阻止。在短日照下,5-FU处理则使农垦58S与农垦58在穗长与颖花数减少的同时,其抽穗反被延迟,可育性受到抑制而结实率显著降低,上述效应还可被随后施用的恢复剂乳清酸所弱化。因此可以认为光敏核不育现象与稻穗发育中核酸代谢的改变有关。     

Effect of aluminium on the NAD+ kinase activity of Euglena gracilis grown heterotrophically

The effect of 2 mM AlCl3 on NAD+ kinase (E.C. 2.7.1.23) activity was studied using Euglena gracilis strain Z grown heterotrophically in darkness at pH 3.5 in the presence of lactate as sole carbon source. The Al-treatment slowed down the culture growth and suppressed the peak of NAD+ kinase activity, which characterizes the beginning of the exponential phase of growth of the control cell cultures. There are two possible explanations of the Al effect: it 1) either prevents the enzyme activation by the Ca-calmodulin (CaM) complex; or 2) suppresses the CaM-dependent NAD+ kinase form. In Euglena cells, a part of the NAD+ kinase activity is enhanced by EGTA and lowered by Ca2+: this peculiar NAD+ kinase activity is unaffected by the Al treatment. This revised version was published online in July 2006 with corrections to the Cover Date.     

玉米赤霉烯酮在冬小麦短日春化中的作用

应用酶联免疫技术,研究了冬小麦品种燕大１８１７ 在不同光周期条件下,体内内源玉米赤霉烯酮（ＺＥＮ） 和ＡＢＡ 含量的变化。结果表明,冬小麦品种燕大１８１７ 具有短日春化性,苗期经４ 周ＳＤ 处理后转到ＬＤ 下能正常抽穗。ＳＤ 诱导春化的幼苗茎尖和叶片中ＺＥＮ 含量高于未经诱导的ＬＤ 幼苗,而在两种光周期条件下生长的幼苗中ＡＢＡ 含量变化趋势并无明显差异。马拉硫磷（ ＭＡＬ） 抑制ＳＤ 幼苗体内ＺＥＮ 含量高峰的出现,也部分抑制抽穗;外源ＺＥＮ 可部分抵消ＭＡＬ对植株的影响,降低茎尖内源ＡＢＡ 含量,并有促进小麦拔节的作用。说明在冬小麦短日春化过程中,ＺＥＮ 具有促进作用,而ＡＢＡ 没有直接影响。     

免疫测定光敏核不育水稻中光敏色素Ⅰ含量

光敏核不育水稻（农垦５８Ｓ）是中国水稻研究中的一个重要发现,在水稻杂交育种上有巨大潜力。研究表明：农垦５８Ｓ的雄性不育性受光周期调控,光敏色素是育性转变过程中光周期反应的光受体,然而,鉴于高等植物中存在至少两种不同的光敏色素分子,并且它们同时存在于水稻中,人们对调节农垦５８Ｓ雄性不育过程的光敏色素分子种类及作用方式仍然不清楚。本文采用酶联免疫吸附测定法（ＥＬＩＳＡ）,比较了不同光周期下农垦５８Ｓ和对照品种农垦５８叶片（光周期感受器官）中光敏色素Ｉ（ｐｈｙＡ）的含量。从农垦５８Ｓ的二次枝梗原基分化期开始,进行１０天的光周期处理。一组为短日照（ＳＤ）,另一组为长日照（ＬＤ）。在第１０个暗期结束前,于暗绿光下收获每株水稻的最上部两片新展叶,立即保存在液氮中。样品在研钵中磨成液氮粉,然后加入提取液（含５０ｍｍｏｌ／ＬＴｒｉｓ－ＨＣＩ和０．２ｍｏｌ／Ｌ巯基乙醇,ｐＨ８．５）匀浆。粗提液经０．５％聚乙烯亚胺（ＰＥＩ）沉淀后,上清液供ＥＬＩＳＡ分析。以燕麦ｐｈｙＡ的多克隆抗体、单克隆抗体分别作ＥＬＩＳＡ的一抗和检测抗体。采用ＥＬＩＳＡ可以专一性地检测水稻ｐｈｙＡ（Ｔａｂｌｅ１）。几次独立的实验说明,光周期处理对ｐｈｙＡ含     

Relationship Between Male Fertility and Endogenous Phytohormones in Photoperiod-Sensitive Genic Male-Sterile Rice

A spontaneous male sterile rice plant (Oryza sativa L. cv. Nongken 58S) "Photoperiod-sensitive Genic Male-sterile Rice has been found to be male sterile under long day cycles (LD) and fertile in short day cycles (SD). The period from secondary rachis-branch and spikelet primodia to pollen mother cell formation in the process of panical development was the photoperiod-sensitive stage for fertility alternation. The phenotype of this mutant was reported to be controlled by two pairs of recessive alleles. The research on relationship between the fertility alternation and phytohormone action in this mutant have been performed by Chinese scientists since 1985. In order to study the mechanism of fertility alternation in Nongken 58S, endogenous IAA, ABA, GA1 and GA4 in apical leaves and reproductive organs in different development stages under LD and SD conditions have been quantiatvely and qualitatively identified by GC-MS-SIM method. It was found that endogenous IAA in apical leaves at the stage of pistil and stamen primodia formation and in panicles at pollen mother cell stage of Nongken 58S with LD condition was deficient comparing with those in SD. Endogenous ABA level in panicles at pollen mother cell stage, in spikelets at uninucleate stage and in anthers at anthesis stage of Nongken 58S-LD were lower than those in SD. ABA levels in corresponding organs and developmental stages of wild type of rice, "Nongken 58" were always higher in LD treatment than those in SD. Endogenous IAA, GA1 and GA4 levels in anthers at anthesis stasge of "Nongken 58"-LD were increased obviously. Thus it appeared that "Nongken 58" possess stronger resistance to LD stress than Nongken 58S. It is concluded that IAA deficiency of reproductive organs at early developmental stage, ABA decrease implying poor resistance to LD stress and reduction of GAs in late developmental stages were the factors causing the anther sterility in Nongken 58S-LD.     

Autoactivation of calmodulin-dependent protein kinase II by autophosphorylation

Autophosphorylation of calmodulin (CaM)-dependent protein kinase II (CaM-kinase II) under limiting conditions (2 microM ATP) decreased progressively with increasing concentrations of a substrate, Pro-Leu-Ala-Arg-Thr-Leu-Ser-Val-Ala-Gly-Leu-Pro-Gly-Lys-Lys (syntide-2), suggesting a competition between the substrate and the autophosphorylation site(s) of the enzyme. The rate and extent of the generation of Ca2+/CaM-independent activity of the enzyme by autophosphorylation were also decreased by the presence of syntide-2. The syntide-2 phosphorylation in the presence of Ca2+/CaM under the limiting conditions reached a steady state, after a lag, when the Ca2+/CaM-independent activity reached a plateau. A linear relationship was observed between the activities in the presence and absence of Ca2+/CaM of the enzyme which had undergone various degrees of autophosphorylation, and the extrapolation of activity in the absence of Ca2+/CaM to zero gave 15-20% of the maximum activity. The steady-state rate of syntide-2 phosphorylation in the presence of Ca2+/CaM by the enzyme that had not undergone prior autophosphorylation was decreased by high concentrations of syntide-2 which suppressed autophosphorylation as well as the generation of Ca2+/CaM-independent activity. These results suggest that although the nonautophosphorylated enzyme possesses a basal low level of Ca2+/CaM-dependent activity, autophosphorylation is required for full activation.     

The Distribution of Enzymes Which Synthesize Nicotinamide Adenine Dinucleotide and Nicotinamide Adenine Dinucleotide Phosphate in Monkey, Rabbit, and Ground Squirrel Retinas

The activity of adenosinetriphosphate:nicotinamide adenylyltransferase (EC 2.7.7.1) was measured in all the layers of monkey, rabbit, and ground squirrel retinas. Nicotinamide adenine dinucleotide (NAD) kinase (EC 2.7.1.23) distribution was measured in monkey and rabbit retinas. An attempt was made to measure NAD synthetase (EC 6.3.5.1), but the activities in the retinal layers were too low to produce a reliable increment in the levels of endogenous NAD. In monkey retina the adenylyl transferase was highest by far in the outer and inner nuclear layers, lower and variable in ganglion cell and fiber layers, and almost absent elsewhere. Rabbit retina differed in that activity was nearly absent in the outer nuclear layer, whereas in the ground squirrel outer nuclear layer activity was double that of the inner nuclear layer. The species differences suggest that adenylyl transferase is almost absent from cone cell nuclei and high in rod cell nuclei. NAD kinase distribution in monkey retina was almost the mirror image of that of adenylyl transferase.