菊苣薄层培养花芽,营养芽分化中内源激素的动态变化

菊苣（Ｃｉｃｈｏｒｉｕｍ ｉｎｔｙｂｕｓＬ．）花梗薄层细胞培养于ＭＳ附加ＮＡＡ 和ＢＡ 或ＩＡＡ 和ＢＡ 的ＭＳ培养基上有花芽或营养芽分化． 花芽分化中内源ＩＡＡ、ＤＨＺ＋ ＤＨＺＲ、ｉＰＡ 含量明显增加,而Ｚ＋ ＺＲ变化不明显．营养芽分化中内源细胞分裂素含量增加明显,而ＩＡＡ 在培养前７ ｄ 含量下降,随后有所增加,在原基形成时含量达原初水平的２／３． 可见,花芽分化比营养芽分化所需内源ＩＡＡ／ＣＴＫ 比值要高     

钾和菊酸钠诱导的离体黄瓜子叶生根过程中内源IAA和ABA含量变化

１３．４ｍｍｏｌ／Ｌ ＫＣｌ和０．６ｍｍｏｌ／Ｌ的菊酸钠诱导离体黄瓜子叶生根过程中,子叶中内源ＩＡＡ含量明显增加,菊酸钠处理的增加趋势高于ＫＣｌ处理;ＡＢＡ含量则显著下降,ＫＣｌ和菊酸钠处理的分别在２４ｈ和８ｈ达到最低,各处理的ＩＡＡ／ＡＢＡ值均明显增加。     

Ｓ３３０７对番茄插枝生根的作用（简报）

经１０mg.L^-1Ｓ307处理过的番茄侧枝,其发根数、根干重、根体积及根系活力都提高而优于ＮＡＡ。在ＮＡＡ和Ｓ３３０７诱导不定根尚未长出前,切段基部内源激素ＩＡＡ含量增加,ＰＰＯ和ＰＯＤ活性下降,可溶性蛋白和可溶性糖含量升高。     

牡丹冬季到内催花过程中内源激素含量的变化

牡丹品种朱砂垒（Ｐａｅｏｎｉａ ｓｕｆｆｒｕｔｉｃｏｓａ Ａｎｄｒ．ｃｖ．Ｚｈｕｓｈａｌｅｉ）在冬季室内催花过程７种内源激素含量变化不同。玉米素核苷（Ｚ＋ＡＲ）、生长素（ＩＡＡ）和赤霉素（ＧＡ３）的含量在花生长发 处于较高水平;而脱落酸（ＡＢ）、异戊烯基腺苷（ＩＰ＋ＩＰＡ）、二氢玉米素核苷（ＤＨＺ＋ＤＨＺＲ）、赤霉素（ＧＡ４）的含量低于上述３种内源激素。激素平衡方面,ＧＡｓ／ＡＢＡ、ＣＴＫｓ／ＡＢ     

表油菜素内酯对湿地松苗内源激素的影响（简报）

１－２ｍｇ／Ｌ表油菜素内酯（ＢＲ）处理,可提高湿地松苗内源ＩＡＡ、ＧＡ３、ＣＴＫ及ＡＢＡ的含量。采用ＳＥＰ－ＰＡＫ Ｃ１８柱纯化样品,ＨＰＬＣ法检测除乙烯以外的内源激素,效果好,操作简便。     

花生种子内源ABA含量变化及其与活力的关系

花生（Ａｒａｃｈｉｓ ｈｙｐｏｇａｅａ Ｌ．）种子发育过程中,胚轴内源ＡＢＡ 含量一直是增加的;种皮内源ＡＢＡ含量在果针入土后４０ ｄ 最大,然后急剧下降;子叶内源ＡＢＡ 含量在果针入土后６０ ｄ 出现高峰,然后有轻微下降。种子活力指数和萌发时内源ＡＢＡ 的净下降量有密切关系。甘露醇可促进离体胚内源ＡＢＡ 合成,１－甲基－３－苯基－５（３－［三氟甲基］－苯基－４－（１氢）－吡啶）抑制子叶内源ＡＢＡ 的合成,子叶和胚轴存在不同的ＡＢＡ 合成途径。种子早熟和早萌处理时,内源ＡＢＡ 含量都下降,胚轴在种子由发育向萌发转换中起着十分重要的作用     

增强UV-B辐射对小麦叶片内源ABA和游离脯氨酸的影响

研究温室种植的小麦在０（ＣＫ）、８．８２ＫＪ／ｍ＾２（Ｔ１）和１２．６ＫＪ／ｍ＾２（Ｔ２）３种剂量的ＵＶ－Ｂ辐射下其内源ＡＢＡ和游离脯氨酸含量的变化。ＵＶ－Ｂ辐射导致叶绿体膜脂脂肪酸配比改变和ＩＵＦＡ降低,叶片ＭＤＡ含量升高及ＡＢＡ和游离脯脯氨酸积累。分析表明,ＵＶ－Ｂ辐射对膜系统的损坏也许是内源ＡＢＡ和游离脯氨酸含量增加的原因之一,而后者也是植物抵抗ＵＶ－Ｂ胁迫所做出的适应性反应。     

Ri T-DNA转化对黄瓜毛状根内源激素水平的影响

利用酶联免疫法和气相色谱法分别测定发根农杆菌Ｒ１０００转化黄瓜子叶产生的三种毛状根内源ＩＡＡ、ＡＢＡ、ｉＰＡｓ、ＺＲｓ、ＧＡ１＋３、ＧＡ４＋７和乙稀含量的变化。结果表明：内源ＩＡＡ、ＡＢＡ和ＧＡ１＋３含量都以Ⅲ型毛状根最高,Ⅱ型毛状根次之,Ｉ型毛状根最低;但ＧＡ４＋７含量顺序恰好与之相反,Ⅲ型毛状根ＧＡ４＋７含量低检测不出。黄瓜对照根和毛状根的ＧＡ１＋３和ｉＰＡｓ含量都分别比ＧＡ４＋７和ＺＲｓ高得     

烟草传粉前后生殖器官中细胞分裂素含量的变化

经免疫亲和层析系统纯化后,用间接竞争ＥＬＩＳＡ 法测定了烟草（Ｎｉｃｏｔｉａｎａ ｔａｂａｃｕｍ ）生殖器官在传粉前后细胞分裂素（ｔ－ＺＲ,ｉＰＡ）含量的变化． 开花前５ ｄ,花药和花丝中的细胞分裂素（ＣＴＫ）含量均达到最高值,以后随雄蕊发育逐渐下降． 授粉使花柱ＣＴＫ 含量急剧上升,授粉后１ ｄ 达到高峰,未经受粉的花柱ＣＴＫ 开花后下降．授粉后２ ｄ,子房中的ＣＴＫ 开始上升,在授粉后４ ｄ 达到最高值,而未受精的子房ＣＴＫ 含量开花后下降． 传粉后雌蕊中ＣＴＫ含量随花粉管生长而有规律地增加,ＣＴＫ 积极参与植物的传粉和受精过程     

不同穗型小麦小花发育过程中幼穗和叶片内源激素水平的动态变化

以“９７鉴１”、“扬麦１５８”和“河南８６７９”分别代表特大穗型、大穗型和穗数型基因型材料,测定和分析了小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ Ｌ．）从小花分化至抽穗期穗部和叶片的内源植物激素水平。幼穗中ＡＢＡ高峰出现在雌雄蕊分化期至药隔形成期之间,出现时间则随穗型增大而推迟。在减数分裂期前,特大穗型幼穗中内源激素水平特别是,ＡＢＡ和ＧＡ１＋３水平明显下降,但ＩＡＡ／ＡＢＡ及ｉＰＡ／ＡＢＡ的比值     

金塔柏扦插不定根形成与内源激素的调控研究

金塔柏（Platycladus orientalis ‘Beverleyensis’）是重要的观赏树种。生长素（IAA）、玉米素（ZT）、脱落酸（ABA）和茉莉酸（JA）在金塔柏扦插不定根再生过程中起着重要的调控作用,但不同发育阶段内源激素的动态变化及其对不定根发生的影响仍不清楚。以金塔柏半木质化枝条为材料,采用连续组织切片技术观察了不定根发生过程,利用高效液相色谱串联质谱法检测了4种内源激素含量的动态变化。结果表明,金塔柏不定根原基起源于愈伤组织、髓射线、木质部、维管形成层、次生韧皮部、皮层、髓射线与形成层交界处等部位,属于多位点发生模式和多类型生根方式。在不定根形成过程中,随着愈伤组织的形成,IAA和ZT含量下降,ABA和JA含量升高;随着根原基的分化,IAA和ZT含量缓慢升高,ABA和JA含量下降;随着不定根形成与伸长,IAA、ZT、JA逐渐升高,ABA维持在低水平。激素平衡分析发现,IAA/ABA比值和IAA/JA比值下降、IAA/ZT比值上升利于愈伤组织的形成,反之利于根原基的诱导分化,而IAA/ABA比值升高,IAA/ZT和IAA/JA维持在较低水平利于不定根形成与伸长。研究结果为揭示不同内源激素对金塔柏扦插不定根再生的调节作用提供了依据。     

杨树试管苗嫩茎生根过程中内源IAA的免疫金银定位

生长素类物质在木本植物生根过程中发挥重要作用。杨树生根与生长素的关系及生根过程中内源激素的变化已有大量报道, 而生根过程中生长素的组织定位分析则尚未见报道。该文应用免疫化学分析方法对741杨(Populus alba × (P. davidiana × P. simonii) × P. tomentosa)嫩茎生根过程中内源IAA在组织中的分布进行了研究。结果显示, 741杨的嫩茎在无外源激素的1/2MS培养基上诱导10天后可生根, 14天后生根率达100%。诱导前, 嫩茎基部组织中几乎没有IAA信号; 诱导8天后, 嫩茎基部维管组织中有大量的IAA积累, 而且中部的维管组织中也有明显的IAA信号(主要分布在韧皮部和维管形成层); 10天后, 形成不定根原基, 此时IAA主要分布在根原基; 12天后, 根原基分化成不定根并突破表皮, IAA在不定根中的分布主要集中在根尖和中柱。该文对741杨的嫩茎生根过程中IAA的组织分布特点及运输途径进行了讨论。     

IBA和NAA对山杜英组培苗生根过程中内源IAA、ABA含量变化的影响

本文研究山杜英组培苗生根过程中内源IAA、ABA含量变化规律。结果表明,培养基添加IBA和NAA后,在生根过程中内源IAA、ABA含量变化类似,根点出现前内源IAA、ABA含量一直上升,根点出现后含量开始下降,产生愈伤组织时两种处理的IAA/ABA分别是2.526和3.226。在不添加外源生长素情况下,内源IAA含量一直维持在较低水平,而内源ABA含量一直呈现上升趋势,IAA/ABA始终都在1.211以下。     

INITIATION AND DEVELOPMENT OF ROOTS IN JUVENILE AND MATURE LEAF BUD CUTTINGS OF FICUS PUMILA L.

Adventitious root formation (ARF) was studied in woody leaf bud cuttings of Ficus pumila L., creeping fig. Juvenile cuttings rooted easily, whereas only mature cuttings treated with indole-3-butyric acid (IBA) attained any rooting success. In the rooting process, both juvenile and mature material exhibited dedifferentiation of phloem ray parenchyma, root initial formation, primordia differentiation, and root elongation. The early stages of adventitious rooting were most critical since few primordia were observed in mature controls. The stages leading up to root primordia differentiation and elongation occurred more rapidly in IBA-treated juvenile vs. mature cuttings; however, time differences in both types between first observable roots and maximum rooting were comparable. Root primordia differentiated from basal callus of some cuttings, but neither these nor the few primordia in mature controls elongated into well-developed roots. Anatomical differences between the juvenile and mature material did not account for rooting disparity, nor did presence of perivascular fibers, sclereids, and laticifers retard rooting.     

Involvement of G1-to-S transition and AhAUX-dependent auxin transport in abscisic acid-induced inhibition of lateral root primodia initiation in Arachis hypogaea L

Previous study indicated that increasing endogenous abscisic acid (ABA) level could inhibit the lateral root (LR) formation of peanuts. In this study, we investigated the mechanisms by which ABA regulated lateral root primordia (LRP) initiation in peanuts (Arachis hypogaea L). Results suggested that ABA inhibited LRP initiation through blocking G1-to-S transition in seedlings and mature roots: e.g. 5.8% increase in the proportion of G1 phase and 18% decrease in the proportion of S phase after ABA treatment for 6 days. Further study of the expression of the cell cycle marker gene for G2-to-M transition in peanut roots suggested that AhCYCB1 expression was regulated by ABA. We also investigated the cooperative regulation of LRP initiation by ABA and indole-3-acetic acid (IAA). ABA treatment greatly reduced the effects of endogenous IAA on mature roots. The expression of the IAA polar transport gene AhAUX1 appeared to be regulated by ABA since ABA inhibited auxin-mediated LRP initiation by suppressing AhAUX-dependent auxin transport in peanut roots. We further examined the effect of ABA on the expression of DR5::GUS and AtAUX1 in the model plant Arabidopsis. The results of Arabidopsis were consistent with that of the peanut.     

Interactions between ethylene, gibberellin and abscisic acid regulate emergence and growth rate of adventitious roots in deepwater rice

Growth of adventitious roots is induced in deepwater rice (Oryza sativa L.) when plants become submerged. Ethylene which accumulates in flooded plant parts is responsible for root growth induction. Gibberellin (GA) is ineffective on its own but acts in a synergistic manner together with ethylene to promote the number of penetrating roots and the growth rate of emerged roots. Studies with the GA biosynthesis inhibitor paclobutrazol revealed that root emergence was dependent on GA activity. Abscisic acid (ABA) acted as a competitive inhibitor of GA activity. Root growth rate on the other hand was dependent on GA concentration and ABA acted as a potent inhibitor possibly of GA but also of ethylene signaling. The results indicated that root emergence and elongation are distinct phases of adventitious root growth that are regulated through different networking between ethylene, GA and ABA signaling pathways. Adventitious root emergence must be coordinated with programmed death of epidermal cells which cover root primordia. Epidermal cell death is also controlled by ethylene, GA and ABA albeit with cell-type specific cross-talk. Different interactions between the same hormones may be a means to ensure proper timing of cell death and root emergence and to adjust the growth rate of emerged adventitious roots.     

Endogenous indole-3-acetic acid during adventitious root formation inPopulus £canadensis Moench.

Indole-3-butyric acid (IBA), phenylacetic acid (PAA) and naphthaleneacetic acid (NAA) were applied at a concentration of 10^-4 mol dm^-3 to stem cutting bases ofPopulus x canadensis Moench. During adventitious root formation, the content of indole-3-acetic acid (IAA) in cutting bases was estimated using the fluorimetric method. In the control variant, a rapid increase in endogenous IAA appeared after 24-h cultivation followed by gradual decrease during the following days. In contrast, the variants treated with IBA, PAA, and especially NAA exhibited firstly a decrease in endogenous IAA content and only afterwards an increase, reaching a maximum 48 h after excision. As root regeneration proceeded gradually, a decrease in the level of endogenous IAA occurred in all treatments. The first adventitious roots appeared in all treatments after 216-h cultivation.     

Influence of indole-3-acetic acid on adventitious root primordia of brittle willow

Summary Removal of the stem apex and certain leaves and axillary buds of brittle willows (Salix fragilis) was employed to limit the supply of endogenous auxin to adventitious root primordia during their formation, which occurs at predetermined sites. Limiting endogenous auxin by this surgical treatment resulted in reduced primordium initiation and, to a lesser degree, primordium growth in cell number. Root primordium cells in surgically treated plants differentiated into mature parenchyma after losing their meristematic character. Application of indole-3-acetic acid (IAA) to surgically treated plants partially overcame the effects of the surgical tretament, increasing root primordium initiation and growth by cell division. When IAA-2-¹⁴C was applied to surgically treated plants, label was detected in root primordium cells by means of autoradiography. Root primordium cells took up more label during the earliest stage of initiation than during a later stage of growth. The data indicate that the initiation of these primordia is more dependent on a supply of auxin than is their subsequent development. Further, the auxin apparently acts directly in the cells which initiate primordia.This investigation was supported in part by Public Health Service Research Grant No. UI 00110-07 (now 5R01 FD 00074-09) from the National Center for Urban and Industrial Health. Paper No. 7138, Min nesota Agricultural Experiment Station.     

Increased endogenous indole-3-acetic acid:abscisic acid ratio is a reliable marker of Pinus massoniana rejuvenation

ABSTRACT

Pinus massoniana is a recalcitrant tree species for rooting in vitro. We rejuvenated 26-year-old P. massoniana trees by successive grafting. Rooting rates of rejuvenated shoots were > 83.1% after rooting induction. We compared endogenous levels of indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellins (GAs) and zeatin-riboside (ZR), and the rhizogenesis ability of axillary shoots of mature and rejuvenated materials in vitro, i.e., somaplants and grafts. Enhancement of the rooting ability of mature materials in vitro following somatic embryogenesis or repeated grafting onto juvenile rootstocks was accompanied by increased IAA and GAs levels, and by decreased ABA levels in scions used as starting material for micropropagation in vitro. Successive subcultures did not influence the rooting ability of shoots from untreated mature material. Rooting ability of shoots in vitro, however, gradually increased with subculture frequency during repeated subculturing in grafting materials. The IAA:ABA ratio in shoots in vitro after grafting five times, and consequently capable of root organogenesis, was higher than in shoots of untreated mature material incapable of root organogenesis in vitro. A high IAA:ABA ratio was detected in scions of somaplants that were capable of rooting in vitro despite subculture times. We found that the endogenous IAA:ABA ratio is a reliable marker for the recovery of root organogenesis in vitro after rejuvenating treatments for mature P. massoniana trees.