Respiratory Response of Dormant Nectarine Floral Buds on Chilling Deficiency

Changes in main biochemical respiratory pathways in dormant nectarine floral buds were studied with nectarine trees （Prunus persica.var, nectariana cv. Shuguang） in order to determine the function of respiration in dormancy release. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of respiratory pathways. Results showed that chilling deficiency blocked the transition of respiratory mode, and made buds stay in a state of high level pentose phosphate pathway （PPP） and low level tricarboxylie acid cycle （TCA）. The decline of PPP and activation of TCA occurred synchronously with the release of dormancy. In addition, the inhibition of PPP stimulated a respiration increase related with TCA. It could be concluded that the function of PPP activation in dormancy release might be limited and PPP declination inducing TCA activation might be part of respiration mode transition mechanism during bud sprouting.

An efficient method for clonal propagation and in vitro establishment of softwood shoots from epicormic buds of teak(Tectona grandis L.)

Softwood shoots were produced from 40 cm long stem segments placed horizontally in flat trays containing sterilized sand under natural light or shade conditions for subsequent rooting and micropropagation studies in teak （Tectona grand＆ L.）. Higher number of shoots （6.17） per log was produced under natural light as compared to shade conditions. Forcing was also better in natural light as compared to shade in terms of shoot length, number of nodes or leaves. For rooting, 2-4 cm long softwood shoots were excised and treated with either indole-3-butyric acid （IBA） or α-naphthyl acetic acid （NAA） at 0, 1000, 2000 or 3000 μmol.L^-1 each or with combinations （1000 ＋ 1000, 2000 ＋ 2000 or 3000 ＋ 3000 μmol.L^-1） and then placed in flat trays containing autoclaved sand at 25 ± 2℃ in 16 h photoperiod at 35 μmol.m^-2.s^-1. After 28 days, softwood cuttings treated with IBA ＋ NAA （3000 ＋ 3000 μmol.L^-1） had highest rooting percentage （89.3%） with 5.5 mean roots. Shoot apex and nodal explants of softwood cuttings were pretreated with 0.1% （w/v） ascorbic acid, boric acid, activated charcoal, citric acid, glutamine or polyvinylpolypyrollidone （PVP） for 24 h to remove phenolic compounds before surface disinfestation. Glutamine （G1） and PVP were equally effective resulting in 60% establishment of shoot apices on MS medium supplemented with 10 μmol.L^-1 6-benzylaminopurine （BAP） ＋ 5 μmol.L^-1 NAA. Using shoot apices, highest （42.80） number of multiple shoots with 54.33 mm shoot length were obtained on MS ＋ BAP （8.8 p.mol.L 1） ＋ IBA （2 μmol.L^-1） after 45 days. Shoots were successfully rooted and acclimatized to greenhouse conditions.

Effect of Photoperiod on Key Enzyme Activities of Respiration in Nectarine Buds During Dormancy Induction

Shuguang （Prunus persica var. nectariana cv. Shuguang） nectarine was used to study effects of photoperiod on key-enzyme activities of respiration during dormancy induction. The dormancy status was determined with sprouting ability. Spectrophotometry was used to investigate activities of phosphohexose isomerase （PGI）, malic dehydrogenase （MDH）, and glucose-6-phosphate dehydrogenase （G6PDH）. The results revealed that short day （SD） treatment promoted dormancy induction while long day （LD） treatment postponed the process. During dormancy induction, PGI activities declined, MDH activities changed little, and G6PDH activities increased both in flower buds and leaf buds. PGI activities and MDH activities in SD treatment were lower than control, and G6PDH activities were higher, which was opposite with LD treatment. The changes of respiratory key-enzyme activities were adjusted by photoperiod and correlated with the development of dormancy induction.

Respiratory Response of Dormant Nectarine Vegetative Buds to High Temperature Stress

High temperature stress （HT） is efficient in breaking endo-dormancy of perennial trees. The effects of HT （50°C） on the respiration of dormant nectarine （Prunus persica var. nectariana cv. Shuguang） vegetative buds were evaluated in the research. We found that bud respiration was transiently inhibited by HT and the pentose phosphate pathway （PPP） and the cytochrome C pathway （CYT） were significantly affected. On the substrate level, PPP was activated in the HT-treated buds compared with the control group. However, the activation did mot occur until hours after HT treatment. The tricarboxylic acid cycle （TCA） in both the HT-treated buds and in the control group proceeded at a low level most of the time compared with total respiration. On the electron transfer level, CYT was transiently inhibited by HT but became significantly active in the later stage. CYT operation in the control group exhibited an attenuation process. The alternative pathway （ALT） fluctuated both in the HT-treated samples and in the control. The results suggest that the temporary CYT inhibition and the following PPP activation may be involved in HT-induced bud dormancy release and budburst mechanisms.

Effects of Photoperiod on Alternative Respiration Pathway in Nectarine Flower Buds During Dormancy Induction

Characteristics of dormancy induction and alternative respiration pathway （also known as cyanide-resistant respiration） of nectarine flower buds in different photoperiods were studied to determine the function of photoperiod and alternative respiration pathway in dormancy induction. Oxygen-electrode system and respiratory inhibitors were used to measure total respiratory rates and rates of alternative respiration pathway. The results showed that total respiration rate （Vt） in flower buds showed to be double hump-shaped curves. Short day raised, brought the first-hump of Vt forward and delayed the second-hump, while long day delayed the whole curve. The capacity （Vast） and activity （pValt） of SD and LD changed synchronously and both showed to be double hump-shaped curves. Short day made the first climax of Vast and pValt existed much earlier, while long day increased their rates significantly. The length of day had little effects on the later period climax. Long day also increased the contributions of altemative respiration pathway in total respiration rate （pValt/Vt）. The changes in alternative respiration pathway were correlated with the induction of dormancy and adjusted by photoperiod. Short day promoted dormancy induction of nectarine trees, while long day delayed it.

Relation Between Endodormancy Induction and Changes in Two Main Electron Transport Pathways of Nectarine Buds

Operation regulations of two main electron transport pathways in nectarine （Prunus persica var. nectariana cv. Shuguang） buds during endodormancy induction were studied to understand possible roles which two main electron transport pathways played in the buds of deciduous fruit trees during endodormancy induction. Respiratory inhibitors （KCN and SHAM） were used to investigate total respiration rate （Vt）, the development and operation of the alternative pathway and partitioning of electrons between the cytochrome and alternative pathways in nectarine buds during endodormancy induction. Results indicated that changes of Vt in flower and leaf buds showed single and double hump-shaped curves, respectively. In endodormancy induction, the capacity （Valt,） and activity （ρValt） of the alternative pathway rapidly increased, but changes of them had different patterns during the entire measuration. At the same time, changes of engagements of the alternative （ρValt/Vt） and cytochrome pathway （ρ′Vcyt/Vt） were opposite, and ρ′Vcyt/Vt was always further higher than ρValt/Vt during the entire measuration. All these results indicated that the development and operation of the alternative pathway played important roles in endodormancy induction, but the cytochrome pathway was the main pathway for mitochondrial electron transport in buds during endodormancy induction.

Effect of auxins on axillary and de novo shoot regeneration from in vitro shoot cultures derived from forced epicormic buds of teak (Tectona grandis L.)

Akram MUHAMMAD, Aftab FAHEEM＊Abstract In this presentation, we report on de novo and axillary shoot regeneration and rooting of shoots maintained over a long term, from cultures of Tectona grandis L. Shoot-tips of teak shoots forced from epicormic buds were used as the starting material for axenie shoot-culture establishment. Long term maintenance of such axenic shoot cultures was carried out by regular sub-culturing on MS media supplemented with N6-benzyleadenine （BA, 8.8 μmol·L^-1） and indole-3-butyric acid （IBA, 2 μmol·L ^1） for 24 months. Vigorously growing shoot tips （2-3 cm long） were inoculated on the MS basal medium supplemented with different concentrations （0, 1, 2, 4, 6, 8 or 10 p.mol-L-~） of either [BA or a-naphthaleneacetic acid （NAA） for rooting. Axillary and de novo shoots were de- veloped from axillary and cut basal ends of shoots, respectively. Shoots growing on auxins were further sub-cultured （every 15 days） and maintained for 45 days. The greatest number of de novo （5.06） as well as axillary shoots （2.85） was observed on the MS medium supplemented with 10 μmol-L^-1 NAA or 8 μmol·L^-1 IBA, respectively, after 45 days. The combinations of both IBA （μmol·L^-1） ＋ NAA （μmol·L^-1） were tested at different concentrations （4 ＋ 4, 6 ＋ 6, 8 ＋ 8） supplemented to a half strength MS basal medium with 0.1% activated charcoal for rooting of decapitated and non-decapitated de novo and axillary shoots. Rooting from non-decapitated de novo shoots was highest （93.33%） with a mean number of roots of 4.61 on this medium, supplemented with 6 μmol·L^-1 IBA ＋ 6 gmol.L l NAA, after 36 days of initial culture. Individual auxin, however, was not effective for root induction. Rooted shoots were acclimatized in a green house and after four weeks plantlets were transferred to the field.

Regeneration of Blue Honeysuckle via Dormant Axillary Buds

The optimum medium for dormant axillary buds culture of blue honeysuckle was screened according to the growth rate and elongation rate by inoculating the buds on culture medium with various 6-BA and iron-salt concentration. About 35 days, the stretched stem buds were divided into strong root system after inoculated on 1/2 MS＋1.0 mg·L^-1 IBA rooting medium. Amount of qualified tissue-cultured young plants could be obtained by the stretched stem buds reproduction.

Effect of Low Temperature Treatment on Agrobacterium-mediated Transformation of Maize Seed Buds

[Objectives]This study was conducted to improve the genetic transformation rate of maize. [Methods]The seeds of maize ＂ Zheng 58＂ as the experimental material were germinated and treated under freezing temperature of-18 ℃ for 30 and 35 min. The EGFP gene was transformed into the growth points of these seed buds by Agrobacterium tumefaciens EHA105. The transformation effect was determined by fluorescence protein detection on transformed buds. [Results]After a certain period of treatment at-18 ℃ following germination and transformation of maize bud growth points with A. tumefaciens,although the survival rate of maize buds was reduced,the percentage of transformed cells significantly increased. [Conclusions]Low temperature treatment can improve the transformation efficiency of A. tumefaciens to the growth point of maize bud.

GC-MS Analysis of Liposoluble Constituents from Buds,Flowers and Fruits of Millettia speciosa Champ.

[Objectives] To study the material foundation of liposoluble constituents from buds,flowers and fruits of Millettia speciosa Champ.and provide a reference for the development of flowers and fruits of Millettia speciosa Champ.[Methods]The liposoluble constituents were extracted from buds,flowers and fruits of Millettia speciosa by Soxhlet extraction and solvent extraction method,and analyzed by GC-MS.[Results]24 compounds were identified from the liposoluble constituents of buds,accounting for 88. 31 % of the total liposoluble constituents,mainly comprising alkanes and olefins compounds( 52. 00%) and alcohols compounds( 17. 46%); 29 compounds were identified from the liposoluble constituents of flowers,accounting for 91. 38 % of the total liposoluble constituents,mainly comprising alkanes and olefins compounds( 60. 64%) and alcohols compounds( 17. 17%); 32 compounds were identified from the liposoluble constituents of fruits,accounting for 80. 01 % of the total liposoluble constituents,mainly comprising alkanes and olefins compounds( 32. 56%),phenyl and its derivatives compounds( 22. 46%) and fatty acids compounds( 12. 54%). 6 compounds were common in buds,flowers and fruits. [Conclusions] Although there were some differences in liposoluble constituents from flowers,fruits,leaves and roots of Millettia speciosa Champ.,the different parts of Millettia speciosa Champ. had development value.

Inducing Adventitious Buds from Tomato Callus and Their Rooting

[ Objective] The aim was to establish efficient regeneration system of tomato so as to study the genetic transformation of chloroplast in tomato. [ Meth- od] The tomato seeds were sterilized and cultured into plantlets. Then, the leaves were cut from plantlets and placed in the MS with 3.0 mg/L 6-BA ＋ 0.3 mg/L IAA to induce callus. Finally, the effect of different hormones and concentrations on induction of adventitious buds from tomato callus and rooting was compared. [Result] The best medium for the induction of differentiation of adventitious buds from callus was： MS ＋ 2.0 mg/L 6-BA ＋ 0.3 mg/L sugar. The best medium for rooting was： 1/2MS ＋ 1.0 mg/L IAA. [ Conclusion] Appropriate sdection of hormone concentrations is the key to establish efficient regeneration system for tomato.

Effects of Different Hormone Proportions on Differentiation and Regeneration of Prtmus avium L. Adventitious Buds

In order to screen the appropriate culture condition for the differentiation and regeneration of Prtmus avium L. adventitious buds, in this study, the effect of different hormone proportions on differentiation and regeneration of shoot tip explants were investigated using Gisela No. 5 and Gisela No. 6 as experimental materi- als. The results showed that, different hormone proportions had extremely significant effects （ P 〈0.01 ） on the differentiation rate of P. avium adventitious buds; the appropriate hormone proportions for Gisela No. 5 and Gisela No. 6 to induce dedifferentiation of adventitious buds were 6-BA 3.0 mg/L ＋ IBA 0.5 mg/L ＋ KT O. 1 mg/L and 6-BA 1.0 mg/L ＋ IBA 0.5 mg/L ＋ KT 0.2 rag/L, respectively. In addition, different hormone proportions had extremely significant effects （P 〈 0.01 ） on the regeneration coefficient and regeneration rate of P. avium adventitious buds; with the hormone proportion of 6-BA 1.0 mg/L ＋ IBA 1.0 mg/L ＋ KT 0.3mg/L, the number of regenerated adventitious buds reached the maximum for both varieties.

Buds Reactivity and Factors Promoting Shoots Proliferation and Rooting of Cashew Seedlings Using in Vitro Tissue Culture Process

Tissue culture techniques are widely used for the mass propagation of many species. In cashew in vitro propagation, some protocols need to be established at this end. The present work was carried out to evaluate the conditions for in vitro regeneration of cashew seedlings from micropropagation by organogenesis on Benin genotypes. Nodal explants from one-month-old cashew seedlings in the greenhouse and cotyledonary nodes from in vitro germination were used for this purpose. BAP and kinetin were evaluated alone at 2.2 mg/L and then the combination of 2.2 mg/L BAP + 0.2 mg/L IBA was also evaluated. The response of axillary bud proliferation on explants was obtained with both cotyledonary nodes and axillary buds from different combinations of growth regulators. However, the best responses were recorded with cotyledonary nodes. When 2.2 mg/L BAP was used, 80% of the explants responded with numerous proliferation (5 to 8) buds (5.75 ± 0.12) with good shoot length (6.73 ± 0.3 cm) on MS medium containing 150 mL coconut water. Rooting was observed with the combination of NAA (2.5 mg/l) + IBA (2.5 mg/l) on 1/2 MS containing 40 g/l sucrose.

Nutrients Modulate T1r2 Transcript Levels in MIN 6 and Primary Cultured Taste Buds Cells under High Glucose Condition

The sweet taste receptors comprised of T1r2 and T1r3, sense glucose concentrations in the gastrointestine. While hyperglycemia was reported to decrease the T1R2 and T1R3 tanscript levels in healthy subjects, no change was observed in type 2 diabetes patients. We investigated which glucose level and nutrients affect those transcript levels in MIN 6 and primary cultured taste buds cells using quantitative Reverse Trancription Polymerase Chain Reaction. High glucose diminished T1r2 transcript levels in MIN 6 and primary cultured taste buds cells. Resveratrol and its analogue augmented transcript levels of T1r1 and T1r2 above normal levels in MIN 6 cells in the medium with 25 mM glucose. Adenine, but not guanine, augmented T1r2 transcript levels of MIN 6 cells in the medium with 25 mM glucose. These results imply that nutrients in meals could affect sweet taste sensitivity by modulating T1r2 transcript levels in response to blood glucose levels.

Rooting of Stem Cuttings of <i>Jatropha platyphylla</i>(Euphorbiaceae) in the Obtaining of Axillary Buds for Grafting

Jatropha platyphylla is considered as a potential source of edible protein, oil, and phenolic compounds with anti-inflammatory activity. The use of stem cutting in vegetative propagation and grafting is as indispensable tools for mass multiplication of superior genotypes and helps in improve planting yield and quality. The study was aimed to investigate the effect of different diameters (10 - 15, 16 - 25 and 26 - 35 mm) and different hormone concentrations of indo-butyric acid (0, 1.5, 3, 6 and 10 g/L), in the rooting of Jatropha platyphylla and to obtain axillary buds to performed grafts. Rooting efficiency was 80% in greenhouse conditions. Hormone concentration and diameter significantly affected the rooting and shooting ability of Jatropha platyphylla stem cuttings. Stem cuttings of 26 - 35 mm have the greatest number, length and dry root weight. 76% survival of the grafted plants was obtained. This demonstrates the necessity to improve the conventional propagation methods with appropriate scientific inputs for more economical and time efficient techniques for standard propagation protocols.

Effects of key growth conditions on endogenous hormone content in tillering stem bases,germination of lateral buds,and biomass allocation in Indocalamus decorus

Physiological responses and changes in growth of Indocalamus decorus Q.H.Dai under different ecological conditions are essential for further understanding growth regulation and adaptive mechanisms and establishing an evidence-based management system for optimal growth. In this study, the endogenous hormone content in tillering stem bases, germination of lateral buds, and biomass allocation of this bamboo species in different growth environments were investigated. Among the endogenous hormones in the basal stems of tillers, indole-3-pyruvic acid and zeatin riboside were highly correlated with lateral buds that germinated to form shoots, while gibberellic acid was highly correlated with lateral buds that germinated to form rhizomes. The best lateral bud germination characteristics were achieved with full sun, a density of six plantlets per pot, and watering every 6 days. I. decorus plantlets used different resource allocation strategies depending on treatment. Different ecological factors influenced endogenous hormones in the bamboo stem base,which affected lateral bud germination and biomass allocation.

Optimum harvesting time of herbaceous peony buds for cutting flowers

The herbaceous peony is one of the cut flowers that has become increasingly popular in the international market in recent years. In the study, 11 cultivars of herbaceous peonies suitable for cutting flowers were selected; different harvesting stages （three or four stages） were identified according to bud development observation （bud firmness, bud diameter, sepal angle, petal angle, and color showing）. Moreover, flower development and vase life were also recorded in the experiment of vase. Bud development observation shows that there are great differences in optimum harvesting stage between the culti- vars, especially between the hybrid peony group and lactiflora group. This implies that bud diameter could not be the only indicator for optimum harvesting stage. Bud description, including sepal opening angle, sepal color, petal color showing, and degree of firmness, is necessary for the determination of the harvesting stage. Among the 11 cultivars,‘Pink Hawaiian Coral＇, ‘Red Charm＇, ‘Edulis Superba＇, ‘Red Magic＇, and ‘Sarah Bernhardt＇ should be harvested at stage 1. ‘Duchesse de Nemours＇, ‘Taff＇, ‘Sorbet＇ and ‘Monsieur Jules Elie＇ should be harvested at stage 2. ‘Kansas＇ should be at stage 3 and ‘Karl Rosenfield＇ at stage 4. The determination of optimum harvesting stage for each cultivar is an important element in cut flower production.

Shrinkage of ipsilateral taste buds and hyperplasia of contralateral taste buds following chorda tympani nerve transection

The morphological changes that occur in the taste buds after denervation are not well under- stood in rats, especially in the contralateral tongue epithelium. In this study, we investigated the time course of morphological changes in the taste buds following unilateral nerve transection. The role of the trigeminal component of the lingual nerve in maintaining the structural integrity of the taste buds was also examined. Twenty-four Sprague-Dawley rats were randomly divided into three groups： control, unilateral chorda tympani nerve transection and unilateral chorda tympani nerve transection ＋ lingual nerve transection. Rats were allowed up to 42 days of re- covery before being euthanized. The taste buds were visualized using a cytokeratin 8 antibody. Taste bud counts, volumes and taste receptor cell numbers were quantified and compared among groups. No significant difference was detected between the chorda tympani nerve transection and chorda tympani nerve transection ＋ lingual nerve transection groups. Taste bud counts, volumes and taste receptor cell numbers on the ipsilateral side all decreased significantly compared with control. On the contralateral side, the number of taste buds remained unchanged over time, but they were larger, and taste receptor cells were more numerous postoperatively. There was no evidence for a role of the trigeminal branch of the lingual nerve in maintaining the structural integrity of the anterior taste buds.

ABCG5-positivity in tumor buds is an indicator of poor prognosis in node-negative colorectal cancer patients

AIM:To analyze the expression of 8 putative cancer stem cell(CSC) markers within colorectal cancer tumor buds and to determine their prognostic impact in patients with this disease. METHODS:Immunohistochemistry was performed on 101 colorectal cancer resections for CK22(to identify tumor buds) as well as CD133,CD166,CD24,CD44s,CD90,EpCAM,ALDH1,and ABCG5,and their expression within tumor buds was evaluated. RESULTS:CD90,CD44s,and CD133 expression in tumor buds was found in less than 5%of all cases. ALDH1,CD24,CD166 were expressed in 16.5%,16.2%,and 34%cases,respectively,while ABCG5 and EpCAM expression was more frequent and found in 35%and 69%of cases,respectively.Of the 8 markers studied,EpCAM and ABCG5 positivity in tumor buds were significantly associated with poor prognosis(P=0.023,P=0.038,respectively) in multivariable analysis with pT and pN classificationP=0.048;hazard ratio(HR) :2.64;95%CI:1.0-6.9,for EpCAM and P=0.029;HR:2.22;95%CI:1.0-4.5,for ABCG5.Poor survival time was particularly striking for lymph node-negative patients with ABCG5-positive buds(P<0.001) . CONCLUSION:Expression of putative stem cell markers EpCAM and ABCG5 within the tumor buds of colorectal cancer are frequently noted and are associated with poor prognosis.

Embryonic Limb Buds Derived Neurotrophins on the Survival of Neurons and the Growth of Axons in Culture in Vitro

Bioactive proteins from SD rat limb buds were extracted and purified. Fractions of 22 ku, 34 ku and 95 ku were proved to have neurotrophic activity to neurons, and the combined activity of these three fractions was the highest. So they were combinedly added into the culture medium of sensor neurons in dorsal root ganglia and motor neurons of anterior spinal cord from 2-week-old embryonic rats, and PBS was added as control. Phase-contrast microscopic and electron microscopic observations, and true cholinesterase measurements were performed to evaluate the survival and changes in growth, function, and ultrastructure of these cultured neurons. In the experimental group, it was found that the AchE activity was higher (P<0. 01), ultrastructural changes in mitochondria,Gorgi's complex and other cell organs were milder than those in the control group. The results showed limb buds derived neurotrophins played an important role in maitaining the survival of the neurons and promoting the growth of axons. It was concluded that embryonic limb buds derived neurotrophins had high neurotrophic activities on neurons' survival and axon growth.