大豆品种早12花序分化形成期间的顶芽内源激素变化

大豆花序分化形成期间 ,顶芽内源玉米赤霉烯酮 ( ZEN)含量先降后升 ;异戊烯基腺嘌呤 ( i PAs)含量在花序发育后期迅速增加 ,说明 ZEN与 i PAs可促进花序的发育。植株的脱落酸 ( ABA)含量短日 ( SD)处理始终比连续照光处理低 ,表明

In vitro Plant Regeneration of Pepper Cytoplasmic Male Sterility (CMS) Lines via Cotyledon Culture

An in vitro shoot regeneration procedure was developed in pepper （ Capsicum annuum L. ） cytoplasmic male sterility （CMS） lines 9704A and 8214A using cotyledon as explant. The callus and bud cluster derived from cotyledon tissue explants were proliferated on Murashige and Skoog （MS） medium supplemented with different combinations of 6-benzladenine （6-BA）, indole-3-acetic acid （IAA）, gibberellic acid （GA3） and silver nitrate （AgNO3）. From the formula of MS appended with 5.0 mg/L 6-BA, 1.0 mg/L IAA and 5.0 mg/L AgNO3, for the explants callus and bud cluster, the maximum differentiation rates （ respectively 100.0% and 58.3% ） and average number of adventitious bud from each explant （respectively 18.8 and 13.2） were obtained. The optimum medium combination for the elongation of adventitious bud was determined to be： MS ＋ 3.0 mg/L 6-BA ＋ 1.0 mg/L IAA ＋ 5.0 mg/L AgNO3 ＋ 2.0 mg/L GA3, from which the elongation rates of buds from callus and bud cluster were both 100%, and the average number of per explant adventitious bud number reached 6.3 and 5.8, respectively. And all the elongated shoots were successfully rooted on half-strength MS medium supplemented with 0.3-0.5 mg/L IAA.

EXOGENOUS Ca^(2+) INHIBITS SENESCENCE-RETARDING EFFECT OF CYTOKININS IN DETACHED RICE LEAVES

Cytokinins and Ca 2+ singly retarded senescence of detached rice leaves.When Ca 2+ was applied together with cytokinins,the effectiveness of cytokinins was significantly reduced.Ca 2+ and cytokinins did not stimulate ethylene production synergistically,ruling out the possibility that ethylene was involved in the inhibition of cytokinin induced senescence retarding effect by Ca 2+ .The experiment with specific compounds known to increase (Ca ionophore A23187),or decrease (EGTA,LaCl 3,Verapamil,chlorpromazine) cytosolic Ca 2+ level indicated that the elevated cytosolic Ca 2+ retards senescence.

Effect of Phytohormones on Adventitious Bud Differentiation from Bulb Scales of Oriental Lily Test-tube Plantlets

[Objective] The purpose of this study is to investigate the effects of differ- ent phytohormones on the adventitious bud differentiation of oriental lily. [Method] The bulb scales of the test-tube plantlets of Tiber, Rodina and Constanta were cul- tured in media supplemented with different cytokinin and auxin at different concen- tration, and then the adventitious buds in each treatment were calculated. [Result] Cytokinins had different influence on the adventitious bud differentiation of the three oriental lily cultivars. Among them, 6-BA had the best effect to induce the adventi- tious bud differentiation from bulb scales of Tiber and Rodina, but there was some difference in the optimal concentration. KT had the best effect to induce the adven- titious bud differentiation of Constanta. The auxins had little influence on the quality of the adventitious bud of the three oriental lily cultivars, but caused some difference in differentiation coefficients. [Conclusion] The most suitable media for the adventi- tious bud differentiation from bulb scales in vitro of Tiber, Rodina and Constanta were MS＋0.2 mg/L 6-BA＋0.2 mg/L 2,4-D, MS＋I.0 mg/L 6-BA＋0.2 mg/L IAA, MS＋ 1.0 mg/L KT＋0.5 mg/L 2,4-D, respectively.

Genome-wide comparative analysis of type-A Arabidopsis response regulator genes by overexpression studies reveals their diverse roles and regulatory mechanisms in cytokinin signaling

Cytokinin is a critical growth regulator for various aspects of plant growth and development. In Arabidopsis, cytokinin signaling is mediated by a two-component system-based phosphorelay that transmits a signal from the receptors, through histidine phosphotransfer proteins, to the downstream response regulators （ARRs）. Of these ARRs, type-A ARR genes, whose transcription can be rapidly induced by cytokinin, act as negative regulators of eytokinin signaling. However, because of functional redundancy, the function of type-A ARR genes in plant growth and development is not well understood by analyzing loss-of-function mutants. In this study, we performed a comparative functional study on all ten type-A ARR genes by analyzing transgenic plants overexpressing these ARR genes fused to a MYC epitope tag. Overexpression of ARR genes results in a variety of cytokinin-associated phenotypes. Notably, overexpression of different ARR transgenes causes diverse phenotypes, even between phylogenetically closely-related gene pairs, such as within the ARR3-ARR4 and ARR5-ARR6 pairs. We found that the accumulation of a subset of ARR proteins （ARR3, ARR5, ARR7, ARR16 and ARR17; possibly ARR8 and ARR15） is increased by MG132, a specific proteasomal inhibitor, indicating that stability of these proteins is regulated by proteasomal degradation. Moreover, similar to that of previously characterized ARR5, ARR6 and ARR7, stability of ARR16 and ARR17, possibly including ARR8 and ARR15, is regulated by cytokinin. These results suggest that type-A ARR proteins are regulated by a combinatorial mechanism involving both the cytokinin and proteasome pathways, thereby executing distinctive functions in plant growth and development.

The BUD2 mutation affects plant architecture through altering cytokinin and auxin responses in Arabidopsis

The ratio of auxin and cytokinin plays a crucial role in regulating aerial architecture by promoting or repressing axillary bud outgrowth. We have previously identified an Arabidopsis mutant bud2 that displays altered root and shoot architecture, which results from the loss-of-function of S-adenosylmethionine decarboxylase 4 （SAMDC4）. In this study, we demonstrate that BUD2 could be induced by auxin, and the induction is dependent on auxin signaling. The mutation of BUD2 results in hyposensitivity to auxin and hypersensitivity to cytokinin, which is confirmed by callus induction assays. Our study suggests that polyamines may play their roles in regulating the plant architecture through affecting the homeostasis of cytokinins and sensitivities to auxin and cytokinin.

A CHASE domain containing protein kinase OsCRL4, represents a new AtCRE1-like gene family in rice

AtCRE1 is known to be a cytokinin receptor in Arabidopsis. The AtCRE1 protein contains CHASE domain at the N-terminal part, followed by a transmitter (histidine kinase) domain and two receiver domains. The N-terminal CHASE domain of AtCRE1 contains putative recognition sites for cytokinin. Five CHASE domains containing proteins were found in rice, OsCRL1a, OsCRL1b, OsCRL2, OsCRL3, and OsCRL4. OsCRL1a, OsCRL1b, OsCRL2 and OsCRL3 contain the four domains existing in CRE1, whereas OsCRL4 only contains the CHASE domain and a putative Ser/Thr protein kinase domain. The authors cloned the encoding gene OsCRL4 and found that it represents a new member of the cytokinin receptor protein in rice.

Regulation of gene expression, growth, and cell survival by IL-4: Contribution of multiple signaling pathways

Interleukin-4 is a cytokine produced by activated T cells, mast cells, and basophils that elicits many important biological responses[1] (see Tab 1). These responses range from the regulation of helper T cell differentiation[2] and the production of IgE[3] to the regulation of the adhesive properties of endothelial cells via VCAM-1[4]. In keeping with these diverse biological effects, high-affinity binding sites for IL-4 (Kd 20 to 300 pM) have been detected on many hematopoietic and non-hematopoietic cell types at levels ranging from 50 to 5000 sites per cell[5],This review will focus on the discrete signal transduction pathways activated by the IL-4 receptor and the coordination of these individual pathways in the regulation of a final biological outcome.

MEK AND p38 MAPK-DEPENDANT PATHWAYS ARE INVOLOVED IN THE POSITIVE EFFECT OF INTERLEUKIN-6 ON HUMAN GROWTH HORMONE GENE EXPRESSION IN RAT MtT/S SOMATOTROPH CELLS

Objective To investigate the effect of interleukin-6(IL-6)on the human growth hormone(hGH)gene expression in a rat somatotropic pituitary cell line MtT/S.Methods The plasmids containing various lengths of hGH gene 5'-promoter fragments were constructed.Stably transfected MtT/S cells were created by cotransfecting the above plasmids and pcDNA3.1(+)with DMRIE-C transfection reagent.After the administration of these cells with IL-6 and/or various inhibitors of signaling transduction pathways,the luciferase activities in MtT/S cells lysis were assayed to demonstrate the effects of IL-6 on hGH gene promoter activity and possibly involved mechanism.Results The 103 U/mL IL-6 stimulated GH secretion and synthesis,and promoted the 5'-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.69 times above the control.Among inhibitors of signaling transduction pathways,mitogen-activated protein kinase kinase(MAPKK/MEK)inhibitor PD98059(40 μmol/L)and p38 mitogen-activated protein kinase(MAPK)inhibitor SB203580(5 μmol/L)completely blocked the stimulatory effect of IL-6.Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells.Neither over-expression of Pit-1 nor inhibition of Pit-1 expression affected IL-6 induction of hGH promoter activity.A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-6.The results showed that the stimulatory effect of IL-6 was abolished following deletion of the-196 to-132 bp fragment.Conclusions IL-6 promotes GH secretion and synthesis by rat MtT/S somatotroph cells.The stimulatory effect of IL-6 on hGH gene promoter appears to require the activation of MEK and p38 MAPK,and a fragment of promoter sequence that spans the-196 to-132 bp of the gene,but may be unlinked with Pit-1 protein.

Human hematopoietic cells express two forms of thecytokine receptor common γ-chain (γc)

Recent studies have revealed that the γ-chain of theIL-2 receptor is shared by the receptors for IL-4, IL7, IL-9, IL-13, and IL-15, and it is therefore also referred toas the common γ-chain (γc). Mutations of γc result inX-linked severe combined immunodeficiency syndrome inhumans, indicating that rye is essential for normal development and function of the immune system. We demonstratethat human hematopoietic cells express two γc transcriptsdiffering in their carboxyl terminal coding region. Onetranscript is the previously reported sequence (γc-long),whereas the newly identified sequence exhibits a deletion of72 nucleotides close to the 3’-end of the open reading frame(γc-short). This alteration predicts a loss of 24 amino acidsincluding a conserved tyrosine residue which is shared byseveral members of the cytokine receptor family. Thepresence of these two distinct forms of rye transcripts wasdemonstrated by sequencing of reversely transcribed andpolymerase chain reaction (RT-PCR) amplified mRNA, restriction digestion of the RT-PCR products, RNAse protection, and Northern blotting from human cell lines andhuman peripheral blood lymphocytes. Furthermore, thetwo variants were present in peripheral blood lymphocytesfrom both female and male donors, which rules out allelicvariants since rye is a single copy gene located on the Xchromosome. A truncation mutant at a site near the observed changes in γc-short has been reported by othersto alter biochemical events activated by cytokines. Thiscombined with the loss of a potential SH2 "docking" sitein γc-short suggests that γc-long and γc-short may link todifferent signaling pathways and may play an importantrole in determining the cellular response to IL-2, IL-4, IL-7, IL-9, IL-13, IL-15.

Multiple Shoots Propagation with Bioreactor Culture of Labisia pumila(Bl.) F. Vill.

This study was to establish the micropropagation system of Labisia pumila （Bl.） F. Vill. and explore the feasibility of mass production of its multiple shoots by bioreactor culture. [Method] The effects of cytokinin or cytokinin/auxin mixture solution at different concentrations on its shoot growth and propagation by nodal segment culture were tested. In order to mass-proliferate its shoots, multiple shoots were suspension-cultured on Murashige and Skoog （MS） liquid medium in the bioreactor. [Results] Thidiazuron （TDZ） showed the highest cytokinin-like activity and the number of its shoots at the TDZ concentration of 0.1 mg/L was the maximum up to 21.5 shoots per explant, without the TDZ effect on shoot elongation, but zeatin signifcantly promoted the shoot elongation and each explant grew 6.8 relatively long shoots at 5.0 mg/L of zeatin. There was no signifcant effect on shoot propagation on induction medium supplemented with auxin. By inoculating 10 g/L （260 shoots） of multiple shoots into 3 L airlift bioreactor containing 2 L MS liquid medium supplemented with 0.1 mg/L TDZ for solution culture, 6 100 multiple shoots with a fresh weight of 183.13 g were harvested. After explant regeneration was conducted in MS solid medium, the regenerated plants were transplanted into flowerpot and the morphologically normal and healthy plants were obtained. [Conclusion] The development of bioreactor technology was conducive to the high efficiency propagation of L. pumila shoot.

Bioinformatics Analysis of Upland Cotton Gene GhCRE1

Cytokinin plays a very important role in plants growth and development,and CRE1 has been identified as a cytokinin receptor.However,the biological function of CRE1 in cotton remains unclear.In this paper,GhCRE1 gene was cloned and its sequence was analyzed by bioinformatics.The results revealed that GhCRE1 had 11 exons and 10 introns,and its molecular weight,theoretical isoelectric point(pI)and number of amino acids differed from those of the homologous gene in Theobroma cacao and Arabidopsis thaliana,with three different protein domains.15 unidentified proteins were found in potential interaction with CRE1 protein and 2 phosphorylation sites on CRE1 protein sequence were predicted by mutiple bioinformatics websites.Additionally,8 cis-acting regulatory elements were detected on CRE1 promoter sequence,and found related to light signal and hormone.These results were conducive to unfolding the function of GhCRE1 in upland cotton.

Potentiality of Vermicompost Humic Acids in Banana in Vitro Micropropagation Clone： Enano Guantanamero

The research was done at Havana Biofabric, Mayabeque Province. The vitro plants of banana （Musa sp） used came from the clone Enano Guantanamero （viand type）. They come from multiplication phase in a Murashige and MS （Skoog medium）. The objective of this work was to study the potentialities of HA （humic acids） for stimulation of rooting and cell division process, searching for completely synthetic hormone substitution due to its high cost. The multiplication medium contained thiamine （2 mg·L^-1）, myo-inositol （100 mg·L^-1）, sugar （30mg·L^-1）. By the use of HA, five treatments were used with total substitution of auxin and cytokinin （TI： HA （10 mg.Ll）; （T2： HA （20 mg·L^-1）; （T3： HA （30mg·L^-1）; （T4： HA （40 mg·L^-1）; （T5： HA （50 mg·L^-1） and the control with 6BAP （benzil amino purine） （4 mg·L^-1） ＋ IBA （indol butyric acid） （0.65 mg·L^-1）, pH of the medium was adjust just before agar were add. The results showed that in the explants under HA treatments, elongation and cell multiplication were favored confirmed by explants great high, root number and length due to dry mass. The total protein content, reduced carbohydrate and peroxidases enzymatic activity were determine. The use of Vermicompost HA in the in vitro micropropagation of banana allow the elimination of rooting phase saving materials and be able to pass explants directly to Acclimatization phase.

三得利公司引进新的植物基因操作技术

三得利公司以几亿日元获得15%Calgcne Pacific公司的股份,通过该公司设立的花品种改良和合并事业,着手开发蓝色的蔷薇和日照好的蔷薇.三得利公司拥有在日本的专卖权.日本的大型钢铁企业、化学企业几家公司等都拥入与增资总额十几亿日元的CalPac公司的合作谈判.消费者比较容易接受的花似乎是日本的重组植物实用化的尖兵.

Influence of Environmental Conditions on Morphogenesis and on Changes of Primary and Secondary Metabolites in Asclepias syriaca L, Derived in Vitro

The object of this study was to adapt in vitro system for morphogenesis and regeneration of microshoots of common milkweed （Asclepias syriaca L.） applying different concentrations of hydrogen ion （H＋） and cytokinin 6-benzylaminopurine （BAP）. The influence of BAP and hydrogen ion （H＋） on the level of primary （chlorophyll a, chlorophyll b and carotenoids） and secondary （flavonoids and hydrolyzable and condensed tannins） metabolites in in vitro grown Asclepias syriaca L, were evaluated. Six different concentrations of BAP （0, 1, 2, 3, 4 and 5 ~tmol/L） and three different concentrations of hydrogen ion （pH 4.5, 5.0 and 5.5） were applied to the woody plant medium （WPM） medium used for microshoots propagation. The most effective morphogenesis of Asclepias syriaca L. was observed in culture medium supplemented with 2 p, mol/L BAP. However, synthesis of primary and secondary metabolites was the most intensive when cytokinin concentration reached the value of 3 gmol/L BAP. It was determined that the activity of hydrogen ion （H＋）, measured as the pH of culture medium, had a significant effect on secondary metabolites in the shoots in vitro.

Fruit Set in Orange with Phytohormones and Its Relation to Endogenous Levels of GA3

This research work aims to contribute in increasing the fruit set in citrus, given its importance in determining fruit yield. The authors evaluated the effects of phytohormones （auxins, gibberellins and cytokinins） in the mooring and features of orange fruit in cultivars Washington navel and Thomson （Citrus sinensis （L.） Osb.）, The experiment was established in a split plot randomized complete block design with five treatments and four replications. Flower tissue samples were stored in liquid N until the extraction of gibberellins and the identification and quantification of GA3. The results showed statistically significant difference （P 〈 0.05） between treatments in the number of fruits retained 129 d after flowering and the percentage of final tie. GA3 content ranged, on a dry weight basis, from 1.66 mg＇g1 in the control to 20.79 mg.g-1 in the high dose. The mean dose （32.2 mg.L-1 auxins, gibberellins 32.2 mg L-1 and 83.2 mg.L-1 cytokinins） caused the largest increase in fruit set.

Effect of Different Concentration of Cytokinins, Carbon Source and Agar on in vitro Propagation of Dahlia sp. through One Single Node

An efficient in vitro protocol for mass production of shoot of Dahlia was developed by using node explant, various carbon sources such as sucrose, glucose, fructose and galactose. Agar concentrations and various growth regulators on in vitro shoot multiplication of Dahlia were studied in the present investigation. The nodal explant from the gardens grown plant were used as testing plant material to develop an efficient protocol for mass propagation of exotic Dahlia to enhance their production for growers and the local markets. This study determined the effect of different carbon sucrose concentrations and gelling agent on in vitro propagation of Dahlia, different carbon sources （sucrose, glucose, fructose and galactose） were investigated, each sugar was added individually to the MS culture medium at the concentrations of 15, 30 and 45 g·L^-1, respectively. Culture medium of each treatment was supplemented with 1,5 mg·L^-1 BA ＋ 1.5 mg·L^-1Kin ＋ 7,0 g·L^-1 agar. The highest number of shoots （7.00）, number of leaves （11.50）, number of node （6.75） and shoot length （8.24 cm） was obtained on MS medium supplemented with 30 g·L^-1 glucose. The least number of shoots （3.38）, number of leaves （5.00）, number of node （3.13） and the least shoot length （2.96 cm） was obtained on 45 g·L^-1 galactose and the least shoot length （2.29 cm） was observed on MS medium with free carbon sources. While the medium with 30 g·L^-1 glucose and 8 g·L^-1 agar gave the highest number of shoots （7.13）, number of leaves （10.75）, number of node （7.13） and shoot length （8.18 cm）. However, the least number of shoots （1.50）, number of leaves （1.88）, number of node （1.63） and the least shoot length （1.26 cm） was obtained with 30 g·L^-1 galactose and 12 g·L^-1 agar. Rooting was readily achieved upon transferring the microshoots onto MS medium supplemented with 0.1 mg·L^-1 IBA, IAA and NAA and 30 g·L^-1 （w/v） different types of carbon sources. The percentage of rooting was less （71.88%） on MS medium containing IAA as compared with IBA or NAA. While the medium having 30 g·L^-1 glucose with 0.1 IBA or NAA mg·L^-1, give the highest percentage of root （100%）, and the highest number of root （3.88） and root length （3.56 cm） was obtained on MS medium containing 30 g·L^-1 glucose with 0.1 mg·L^-1 IBA. More than 98% of rooted plantlets were established in the greenhouse.