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1.
本文以水稻亚种间杂交组合Ⅱ优2070及恢复系2070、Ⅱ优419及恢复系中419为材料.应用HPLC和ELISA法测定灌浆期间根系伤流液中根源细胞分裂素(CTKs)种类和数量以及稻叶和籽粒中细胞分裂素组分含量的变化,研究表明在亚种杂交稻及其恢复系灌浆起始阶段,玉米素(Z) 占总CTKs的比例高达62.8%-89.1%,是根系伤流液中细胞分裂素的主要成分,而二氢玉米素(di- HZ)和二氢玉米素核苷(diHZR)则在灌浆后期明显上升.这种变化动态与Ⅱ优2070和2070剑叶中ZRs(Z ZR)、diHZRs(diHZ diHZR)的波动变化是相符合的。与根系伤流液的主要细胞分裂素组成不同,IPAs在叶片和籽粒中占总CTKs量的比例最高。说明在灌浆期间,根系伤流液中CTKs的种类及其活性存在着变化,这种变化可能与细胞分裂素代谢酶活性变化及其相关酶基因表达的不同有关。讨论了强、弱势粒的CTKs组分的变化与籽粒结实的可能关系。  相似文献   

2.
30%己乙水剂对玉米根系伤流液及其组分的影响   总被引:7,自引:0,他引:7  
以玉米3138为材料,在大田和PVC管栽条件下研究了应用植物生长调节剂30%己乙水剂对玉米根系伤流量、伤流中无机离子流量、氨基酸组分及流量、激素流量等的影响,结果表明:30%己乙水剂可提高玉米根系伤流量,特别是大喇叭口期和籽粒形成期;提高了伤流中K,P,Ca,Mg,Si,Zn,Mn,Fe,B,Mo,Cu等无机元素流量,氨基酸总流量提高,主要的运输形式氨基酸Ser,Clu,Lys.Arg,Val,Ala,Leu,I1e,His,Try,Phe流量均明显增加,非蛋白质氨基酸GAba大幅度增加,伤流液中IAA在籽粒形成和灌浆期提高,授粉后伤流中Gas提高,CTKs在籽粒形成期提高,ABA在灌浆期提高,吐丝前低于对照。表明30%已乙水剂可促进根系吸收和合成物质向地上部分的输送,对促进地上部发育有重要作用。  相似文献   

3.
拟南芥中4种细胞分裂素的高效液相色谱法测定   总被引:1,自引:0,他引:1  
应用高效液相色谱法同时测定拟南芥中4种细胞分裂素组分玉米素(Z)、玉米素核苷(ZR)、6-r,r-二甲基烯丙基氨基嘌呤(2ip)和6-r,r-二甲基烯丙基氨基嘌呤核苷(2ipr)含量。结果表明,采用反相色谱柱Waters C18柱(4.6×250mm,5μm),在35℃以乙腈和三乙胺缓冲液为流动相梯度洗脱,流速1ml/min,在270nm处能准确检测出拟南芥中4种细胞分裂素组分的含量,检测限达0.001μg/ml。  相似文献   

4.
细胞分裂素的混合抗体型免疫亲和柱的制备与应用   总被引:2,自引:0,他引:2  
陈以峰  郑志富 《生物技术》1994,4(5):22-23,26
内源细胞分裂素可以分成三组:异戊烯基腺苷组(iPAs)、玉米素核苷组(ZRs)、二氢玉米素核苷组(DHZRs)。从这三组分别选iPA、ZR、DHZR为半抗原合成免疫原,获得的三种免抗血清基本上只识别相应组的细胞分裂素。将经初纯化的三种抗血清偶联到CNBr活化的Sepharose4B上制成免疫亲和柱。在其中的一根柱床高2.1cm、体积3.55ml、直径1.5cm的亲和柱上,在流速1.5ml/min、80%冷甲醇为洗脱剂的条件下测得该柱容量为3.6—4.0μg、回收率达93.9%~98.3%。用该柱对丝瓜茎木质部伤流中细胞分裂素进行了纯化.表明能够用此柱对植物粗提液中的细胞分裂素进行快速分离纯化。  相似文献   

5.
基于根系诱导的细胞分裂素对玉米生长的影响,本研究探讨了根系深度与旱后复水玉米(Zea mays)补偿性生长的关系。以苗期玉米为试验材料,从4月20日—6月3日,设置充分供水、充分供水且断根、旱后复水、旱后复水且断根4个处理。在玉米干旱胁迫结束时,即出苗后第28天对其进行断根处理,用薄背刀在盆纵向的中间位置水平横切,使根系完全断为两半以得到浅根系。结果表明:与充分供水相比,干旱抑制玉米生长,使其地上生物量、根系生物量与总生物量大幅下降;未断根条件下,复水后,根系能感知水分刺激产生细胞分裂素,且细胞分裂素会经由伤流液转运至玉米叶片;叶片中细胞分裂素含量水平的增加能促进其净光合速率的提高,并可使玉米地上生物量、根系生物量与总生物量增加,进而促进玉米复水后的较快生长;而断根条件下,深根被去除,复水后,浅根虽能感受水分刺激,但并不能产生大量细胞分裂素,进而导致叶片中细胞分裂素含量不能明显升高,净光合速率也不能明显增加,各部分生物量增加亦不明显,玉米不能够快速生长。总之,根系诱导的叶片细胞分裂素是旱后复水玉米补偿性生长的核心因素;而断根使得深根大量丧失,复水后玉米浅根系不易产生细胞分裂素,从而不能引起补偿性生长,即深根对玉米的旱后复水玉米补偿性生长起着关键性作用。  相似文献   

6.
陈以峰  周燮 《生物技术》1995,5(4):27-29
本文报道二氢玉米素核苷(DHZR)组细胞分裂素放射免疫测定法(RIA)的研制结果。以(3H)二氢玉米素作示踪剂,测得免抗DHZR抗血清的效价为1:1370(B%=30%)。该抗血清主要与本组细胞分裂素发生交叉反应。回收率为96.9%,灵敏度为12fmol DHZR/管,检测线性范围为0.1 ̄100pmolDHZR/管。批内误差CV=4.3,批间误差CV=2.0%。对基于同一免抗血清的DHZR组细胞  相似文献   

7.
细胞分裂素是五类植物激素中最年轻的一员,自1955年Miller、Skoog等从鲱鱼精子的DNA降解物中发现激动素到现在还不过二十余年。虽然激动素——6-呋喃氨基嘌呤是最早发现的刺激细胞分裂的活性物质,但迄今还没有发现它在植物细胞中的天然存在。但是人们从大量的探索中发现在不少植物幼嫩器官中,存在着刺激细胞分裂的物质。63年Letham首次从甜玉米灌浆期籽粒中提取并结晶出有效物质,命名为玉米素(Zeatin)。接着于  相似文献   

8.
以"先玉335"和"鑫鑫2号"为试验材料,于花后25 d喷施噻苯隆和噻苯隆-乙烯利复配剂,清水为对照,探究噻苯隆-乙烯利复配对玉米籽粒灌浆后期灌浆特性的影响及其激素调控机理。结果表明:噻苯隆-乙烯利复配可以缩短籽粒灌浆快增期和缓增期的灌浆持续时间,提高灌浆平均速率和籽粒重量,显著增加春玉米灌浆后期籽粒中生长素(IAA)和赤霉素(GA)含量,降低脱落酸(ABA)和细胞分裂素(CTK)含量;同时显著提高灌浆期籽粒IAA与ABA、GA与ABA比例,降低CTK与IAA、CTK与GA比例,对CTK与ABA、GA与IAA比例影响较小。相关分析表明,噻苯隆-乙烯利复配处理后,春玉米籽粒中ABA和CTK含量与灌浆快增期速率呈显著负相关。本研究表明,噻苯隆-乙烯利复配主要通过影响籽粒中IAA、ABA、CTK和GA含量及其比例,从而调控春玉米籽粒灌浆进程,最终实现春玉米产量提高,熟期提前的功效。研究为噻苯隆-乙烯利复配应用到玉米生产上提供理论及试验依据。  相似文献   

9.
牡丹冬季室内催花过程中内源激素含量的变化   总被引:11,自引:0,他引:11  
牡丹品种朱砂垒(PaeoniasuffruticosaAndr.cv.Zhushalei)在冬季室内催花过程中7种内源激素含量变化不同。玉米素核苷(Z ZR)、生长素(IAA)和赤霉素(GA3)的含量在花生长发育过程中处于较高水平;而脱落酸(ABA)、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/ABA、IAA/ABA处于较高水平,变化幅度较大。在催花过程中,内源激素以及其平衡影响牡丹花的生长发育。本研究结果对牡丹花期调控提供理论依据。  相似文献   

10.
研究了细胞分裂素在玉米愈伤组织诱导的植株再生中的作用,结果表明低浓度(0.2mg/L)的细胞分裂素能促进玉米幼胚诱导的愈伤组织再生,6-BA的效果比KT更好。不同品种的玉米幼胚诱导的愈伤组织的再生能力差异显著,普甜1号和苏玉1号的再生频率高达78%和75%,糯玉米和掖单9号仅为10%和8%。植株再生途径也有所不同,普甜1号以器官发生为主要途径,苏玉1号则以体胚发生途径为主。经长期继代的愈伤组织失去  相似文献   

11.
Conifer trees are routinely manipulated hormonally to increase flowering, branching, or adjust crown shape for production purposes. This survey of internal cytokinin levels provides a background for such treatments in Abies nordmanniana, a tree of great economic interest. Reference points in the crown and root system were sampled destructively in 4- and 6-year-old trees and analyzed for a range of cytokinins by LC-MS/MS. No seasonal patterns were detected in the root samples, and a major portion of cytokinin was in conjugated forms. Dramatic and consistent seasonal changes occurred in the crown, at levels 17–65 times higher than in the root. Predominant among crown cytokinins was ZR, except in the needles where IPR was also prominent. Within the crown, cytokinin profiles in different organs differed consistently. The leader bud showed a pronounced mid-June minimum, and a maximum later in summer. Subapical buds showed the same June minimum but peaked in mid autumn at a much lower level. Maxima in these buds were preceded by peaks in the subapical stem. Parallel patterns were observed in homologous tissues on branches.This pattern is consistent with two surges beginning in the uppermost stem tissues leading to subsequent accumulation or stimulated production within the buds. Strong differential hormonal profiles between adjacent buds with different fates agree with recent evidence of localized cytokinin production. The data suggest a reduced role of root-derived cytokinins in crown development. Practical cytokinin treatments for crown-shape regulation require close attention to dosage as well as precise timing and positioning.  相似文献   

12.
Changes in exudation rate and cytokinin activities in the exudates were measured in two varieties of rice (Oryza sativa L.), cv Nipponbare (a Japanese normal cultivar) and cv Akenohoshi (a high-yielding cultivar). The exudation rates of Akenohoshi, the leaves of which remained green for a longer time, were higher than those of Nipponbare after the booting stage. Cytokinin activities in the exudates of Akenohoshi were higher than those of Nipponbare during the ripening period. Cytokinins in the exudates collected during the middle of the ripening stage were analyzed with mass spectrometry using deuterium-labeled standards. trans-Zeatin, trans-ribosylzeatin, and N6-isopentenyladenosine were detected as free cytokinins, and zeatin was detected in the hydrolysates of highly polar fractions (“conjugated zeatin”) in the exudates of both cultivars. Conjugated zeatin was the predominant cytokinin in both cultivars. Therefore, we suggest that conjugated zeatin is an important form of cytokinin during the ripening stage. The level of each of the cytokinins in Akenohoshi was higher than that in Nipponbare. Also, we discuss the correlation between the leaf senescence and cytokinin content in root exudates.  相似文献   

13.
This paper reports the ways that the differences in leaf senescence are related to grain filling, grain yield, and the dynamics of cytokinins (CKs) in the top three leaves of four field-grown new plant type (NPT) rice, a tropical japonica developed at the International Rice Research Institute, Philippines, to increase the yield potential of rice. The chlorophyll content in leaves decreased from flowering to maturity in all the NPT lines, whereas the grain filling percentage was higher in the fast-senescing NPT line than in slow-senescing NPT line. Grain yield was positively correlated with senescence in the flag leaf. Rapid changes in the CK levels were recorded in the leaves of the fast-senescing line, whereas the CK levels were relatively stable in leaves of the slow-senescing line, suggesting that the dynamics of CKs in the fast-senescing line are vital for fast senescence. There were no significant changes in bioactive CKs, CK O-glucosides (storage CKs), and cis-zeatin derivatives in different leaves of the slow-senescing NPT line between 0 and 3 weeks after flowering, suggesting that the content of these CKs is relatively stable during grain filling. A progressive increase in levels of bioactive CKs was positively correlated with gradual accumulation of CK N-glucosides (inactive CKs) in the top three leaves of the slow-senescing NPT line, whereas the decrease of bioactive CKs in the flag leaf of the fast-senescing line was accompanied by accumulation of CK O-glucosides. These results suggest that there is a higher rate of biosynthesis and/or import of bioactive CKs as well as their turnover which may favor delay of leaf senescence in the slow-senescing NPT line.  相似文献   

14.
The effects of inorganic nutrients on the levels of endogenouscytokinins in plants of sunflower (Helianthus annuusL.) grownin sand culture were studied. Low levels of nitrogen resultedin rapid decreases in the levels of cytokinins extracted fromleaves, buds, roots, and root exudates. Similar effects wereobserved with phosphorus deficiency, but the effects of potassiumdeficiency on the cytokinin content of leaves was less marked.The cytokinin content was higher in plants supplied with nitrogenas nitrate than in those supplied with ammonium sulphate orammonium nitrate. The decline in cytokinin levels in derooted shoots and detachedleaves could be reversed by supplying them with nutrient solution.Although leaves on intact plants may normally be dependent uponthe supply of cytokinins from the roots, isolated leaves havethe capacity for cytokinin production when supplied with inorganicnutrients.  相似文献   

15.
The cytokinin content of Xanthium strumarium L. plants decreased markedly when they were exposed to short days (SD). There was a significant decrease in the content of the butanol-soluble cytokinins of the mature leaves after only 5 SD cycles, and after 10 SD there was no significant cytokinin activity in butanol extracts; the changes in the young leaves were less marked. Most of the cytokinin activity in mature leaves appears to be present in the aqueous fraction, whereas in young leaves most activity occurs in the butanol-soluble fraction. SD treated plants produced less root exudate than LD plants, but there were no significant differences in the amounts of cytokinin in the root exudates from LD and SD plants collected over an equivalent time period. The cytokinin levels of SD-induced leaves remained low even when transferred back to LD. The observed differences in cytokinin levels did not appear to be the result of photosynthetic differences. Exposure of detached leaves to LD or SD did not result in differences in cytokinin content. It is not clear whether the observed changes in cytokinin levels in the leaves under SD are involved in the flowering response, but they may be causally related to a reduced chlorophyll content observed in SD-induced leaves.  相似文献   

16.
Yang J  Zhang J  Wang Z  Zhu Q  Liu L 《Planta》2002,215(4):645-652
The possible regulation of senescence-initiated remobilization of carbon reserves in rice (Oryza sativa L.) by abscisic acid (ABA) and cytokinins was studied using two rice cultivars with high lodging resistance and slow remobilization. The plants were grown in pots and either well-watered (WW, soil water potential = 0 MPa) or water-stressed (WS, soil water potential = -0.05 MPa) from 9 days after anthesis until they reached maturity. Leaf water potentials of both cultivars markedly decreased at midday as a result of water stress but completely recovered by early morning. Chlorophyll (Chl) and photosynthetic rate (Pr) of the flag leaves declined faster in WS plants than in WW plants, indicating that the water deficit enhanced senescence. Water stress accelerated starch remobilization in the stems, promoted the re-allocation of pre-fixed (14)C from the stems to grains, shortened the grain-filling period and increased the grain-filling rate. Sucrose phosphate synthase (SPS, EC 2.4.1.14) activity was enhanced by water stress and positively correlated with sucrose accumulation in both the stem and leaves. Water stress substantially increased ABA but reduced zeatin (Z) + zeatin riboside (ZR) concentrations in the root exudates and leaves. ABA significantly and negatively, while Z+ZR positively, correlated with Pr and Chl of the flag leaves. ABA, not Z+ZR, was positively and significantly correlated with SPS activity and remobilization of pre-stored carbon. Spraying ABA reduced Chl in the flag leaves, and enhanced SPS activity and remobilization of carbon reserves. Spraying kinetin had the opposite effect. The results suggest that both ABA and cytokinins are involved in controlling plant senescence, and an enhanced carbon remobilization is attributed to an elevated ABA level in rice plants subjected to water stress.  相似文献   

17.
Cytokinin, auxin and gibberellin-like substances were bio-assayed in extracts from developing ears of wheat plants grown in various conditions. Changes in cytokinin activity along the ears may be related to the earlier flowering in the middle of the ear. Ears on the main stems of plants from which all the tillers had been removed contained less cytokinin than the main-stem ears of normal tillered plants. When grain development was stopped by preventing fertilization of the ovules the ear contained more cytokinin than normal ears. With de-tillered plants, removing flag leaves before anthesis increased cytokinin, gibberellin and auxin in the ears; later removal of flag leaves did not affect cytokinin but decreased gibberellin in the ears. Conversely, removing ears before anthesis did not affect cytokinin or auxin in the flag leaves, but their gibberellin was less than that of flag leaves on intact plants. Treatment of wheat ears with zeatin did not affect grain weight or number per ear which supports the conclusion that the growth substances in the ear may be adequate for normal grain growth.  相似文献   

18.
The characteristics of dry matter production before and after heading and the relationships between photosynthesis of flag leaves and dry matter accumulation in panicles were investigated on super high-yielding rice cv. Xieyou 9308 (the yield of up to 12 t/ha) with rice cv. Xieyou 63 as a control. The results showed that (i) the capacity of dry matter production before and after heading in Xieyou 9308, i.e. biomass and daily dry matter production, was remarkably higher than that in Xieyou 63, especially after heading; (ii) CO2 assimilation capacity in flag leaves in Xieyou 9308, namely Leaf Source Capacity (LSC), was also significantly higher than that in Xieyou 63, and the supply of photosynthate in leaves and the demand of grain filling were completely synchronous in Xieyou 9308, but photosynthetic function in flag leaves in Xieyou 63 declined sharply 20 days after heading and it was not enough to meet the demand of grain filling. These results confirmed that high efficient photosynthetic function in  相似文献   

19.
The characteristics of dry matter production before and after heading and the relationships between photosynthesis of flag leaves and dry matter accumulation in panicles were investigated on super high-yielding rice cv. Xieyou 9308 (the yield of up to 12 t/ha) with rice cv. Xieyou 63 as a control. The results showed that (i) the capacity of dry matter production before and after heading in Xieyou 9308, i.e. biomass and daily dry matter production, was remarkably higher than that in Xieyou 63, especially after heading; (ii) CO2 assimilation capacity in flag leaves in Xieyou 9308, namely Leaf Source Capacity (LSC), was also significantly higher than that in Xieyou 63, and the supply of photosynthate in leaves and the demand of grain filling were completely synchronous in Xieyou 9308, but photosynthetic function in flag leaves in Xieyou 63 declined sharply 20 days after heading and it was not enough to meet the demand of grain filling. These results confirmed that high efficient photosynthetic function in leaves after heading and its complete synchronization with grain filling are the key approaches to super high yield of rice.  相似文献   

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