ENHANCEMENT OF POLLEN GERMINATION BY PROMOTIVE FACTORS IN INCOMPATIBLE POLLEN

Cultivated and wild almonds are self-incompatible and thus require outcrossing by insect pollinators to produce viable seed. In commercial production, considerable efforts are directed towards placement and selection of cultivars for cross-pollination. However, since honeybees do not distinguish between the different cultivars, stigmas are usually covered by a mixture of both compatible and incompatible pollen. Using in vitro assays, we demonstrated that pollen extracts promoted germination in self pollen with no inhibitory effects observed. Elemental analyses of pollen extracts showed that enhanced levels of Ca, Mg, K, Na, and P were eluted from the grains. From this, we raise the question of possible interaction between compatible and incompatible pollen, and speculate that incompatible pollen grains may support and enhance germination of adjacent compatible pollen.

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Incompatibility, stamen movement and pollen economy in a heterostyled tropical forest tree, Cratoxylum formosum (Guttiferae)

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1982.0010 ◽

1982 ◽

Vol 214 (1195) ◽

pp. 273-283 ◽

Cited By ~ 22

Keyword(s):

Critical Level ◽

Pollen Grains ◽

Forest Tree ◽

Incompatible Pollen ◽

Insect Visitation ◽

Small Pollen ◽

Evolutionary Step ◽

Novel Method ◽

Compatible Pollinations ◽

Compatible Pollen

Cratoxylum formosum shows all the classical features of a distylic species. The two types are: long-styled plants with short stamens and small pollen grains and short-styled plants with long stamens and large pollen grains. Compatible pollinations are only between the two types; incompatible pollen tubes are inhibited in the style. A significant morphological feature distinguishes Cratoxylum from distylic plants in other families. Instead of having a small number of anthers making well separated narrow discs in the two types, Cratoxylum has many anthers (144) and they are arranged on staminal bundles that produce long cylinders of anthers that partially occupy similar height zones in the two types of flower. A novel method of separation of the two height zones is achieved by the bending of the stamens of the long-styled type when the flower opens, which converts the cylinder to a narrow disc of anthers at the same height as the ‘short’ stigma. The bending coincides with anther dehiscence and is slightly later than the first daily insect visitation. The anthers return to the upright position later in the day, when the pollination is complete. There was a 20-fold difference between the amounts of pollen deposited on the two types of stigmas. The ‘long’ stigmas received 1200 pollen grains per flower, in the ratio of 46 ‘long’ to 54 ‘short’, which is close to the ratio of two types of pollen produced in the population. This random deposition of pollen on ‘long’ stigmas is, however, more than adequate for the 36 seeds produced per flower. ‘Short’ stigmas received only 64 pollen grains per flower, in the ratio of 90 ‘long’ to 10 ‘short’, and several flowers had below the critical level of 36 compatible pollen grains for full seed production. Pollen loads of the pollinating bee, Apis javana , consisted of ‘long’ and ‘short’ pollen on the thorax in the ratio found on the ‘long’ stigma, and on the head of the bee in a ratio close to the 9:1 found on the ‘short ’ stigma. The corbicular loads reflected accurately the pollen of the tree in which the bee was caught. For Cratoxylum the accurate positioning of the anthers of the long-styled plant in relation to the visiting bees head was an important evolutionary step in the effective pollination of the short-styled form, which, at least in this species, is one critical and highly selected feature of the system.

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Synthesis, Structure and In Vitro Cytotoxic Activity of Novel Cinchona—Chalcone Hybrids with 1,4-Disubstituted- and 1,5-Disubstituted 1,2,3-Triazole Linkers

Molecules ◽

10.3390/molecules24224077 ◽

2019 ◽

Vol 24 (22) ◽

pp. 4077 ◽

Cited By ~ 3

Author(s):

Jernei ◽

Duró ◽

Dembo ◽

Lajkó ◽

Takács ◽

...

Keyword(s):

Cytotoxic Activity ◽

Malignant Cell ◽

Conformational Space ◽

In Vitro Assays ◽

Inhibitory Effects ◽

Cyclization Reactions ◽

Click Reactions ◽

Metal Catalyzed ◽

Dft Modelling

By means of copper(I)-and ruthenium(II)-catalyzed click reactions of quinine- and quinidine-derived alkynes with azide-substituted chalcones a systematic series of novel cinchona-chalcone hybrid compounds, containing 1,4-disubstituted- and 1,5-disubstituted 1,2,3-triazole linkers, were synthesized and evaluated for their cytotoxic activity on four human malignant cell lines (PANC-1, COLO-205, A2058 and EBC-1). In most cases, the cyclization reactions were accompanied by the transition-metal-catalyzed epimerization of the C9-stereogenic centre in the cinchona fragment. The results of the in vitro assays disclosed that all the prepared hybrids exhibit marked cytotoxicity in concentrations of low micromolar range, while the C9-epimerized model comprising quinidine- and (E)-1-(4-(3-oxo-3-(3,4,5-trimethoxyphenyl)prop-1-en-1-yl)phenyl) fragments, connected by 1,5-disubstituted 1,2,3-triazole linker, and can be regarded as the most potent lead of which activity is probably associated with a limited conformational space allowing for the adoption of a relatively rigid well-defined conformation identified by DFT modelling. The mechanism of action of this hybrid along with that of a model with markedly decreased activity were approached by comparative cell-cycle analyses in PANC-1 cells. These studies disclosed that the hybrid of enhanced antiproliferative activity exerts significantly more extensive inhibitory effects in subG1, S and G2/M phases than does the less cytotoxic counterpart.

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Engraftment after infusion of CD34+ marrow cells in patients with breast cancer or neuroblastoma

Blood ◽

10.1182/blood.v77.8.1717.1717 ◽

1991 ◽

Vol 77 (8) ◽

pp. 1717-1722 ◽

Cited By ~ 340

Author(s):

RJ Berenson ◽

WI Bensinger ◽

RS Hill ◽

RG Andrews ◽

J Garcia-Lopez ◽

...

Keyword(s):

Breast Cancer ◽

Stage Iv ◽

In Vitro Assays ◽

Hematopoietic Progenitors ◽

Cd34 Antigen ◽

Stage Iv Breast Cancer ◽

Cd34 Cells ◽

Selection Of ◽

Marrow Cells

Abstract The CD34 antigen is expressed by 1% to 4% of human and baboon marrow cells, including virtually all hematopoietic progenitors detectable by in vitro assays. Previous work from our laboratory has shown that CD34+ marrow cells can engraft lethally irradiated baboons. Because the CD34 antigen has not been detected on most solid tumors, positive selection of CD34+ cells may be used to provide marrow cells capable of engraftment, but depleted of tumor cells. In seven patients with stage IV breast cancer and two patients with stage IV neuroblastoma, 2.5 to 17.5 x 10(9) marrow cells were separated by immunoadsorption with the anti-CD34 antibody 12–8 and 50 to 260 x 10(6) positively selected cells were recovered that were 64 +/- 16% (range 35% to 92%) CD34+. The patients received 1.0 to 5.2 x 10(6) CD34-enriched cells/kg after marrow ablative therapy. Six patients engrafted, achieving granulocyte counts of greater than 500/mm3 at 34 +/- 10 (range 21 to 47) days and platelets counts of greater than 20,000/mm3 at 46 +/- 14 (range 28 to 66) days posttransplant. Five of these patients showed durable engraftment until the time of death 82 to 386 days posttransplant. One patient failed to sustain engraftment associated with metastatic marrow disease. Three patients died at days 14, 14, and 17 posttransplant, two of whom had evidence of early engraftment. These studies suggest that CD34+ marrow cells are capable of reconstituting hematopoiesis in humans.

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The effect of pollination intensity and incompatible pollen on seed set in Turnera ulmifolia (Turneraceae)

Canadian Journal of Botany ◽

10.1139/b84-175 ◽

1984 ◽

Vol 62 (6) ◽

pp. 1298-1303 ◽

Cited By ~ 98

Author(s):

Joel S. Shore ◽

Spencer C. H. Barrett

Keyword(s):

Regression Analysis ◽

Seed Set ◽

Pollen Grains ◽

The Self ◽

Time Intervals ◽

Pollination Experiments ◽

Controlled Pollination ◽

Incompatible Pollen ◽

Turnera Ulmifolia ◽

Compatible Pollen

Controlled pollination experiments were performed on the self-incompatible distylous herb Turnera ulmifolia L. to investigate the effects of pollination intensity and large amounts of incompatible pollen on seed set. In the first experiment, known numbers of compatible pollen grains ranging from 1 to 100 were applied to stigmas of the floral morphs. In both morphs, increasing amounts of pollen generally resulted in increased levels of seed set, although considerable variance was observed at all pollination intensities. Approximately two to seven pollen grains are required to produce a single seed and more than 95 grains are required to achieve maximum seed set in T. ulmifolia. Regression analysis of the seed set data failed to detect a difference in the response of the floral morphs to pollination intensity. In the second experiment, known proportions of compatible and incompatible pollen were applied to stigmas at various time intervals. Most treatments involving mixtures of compatible and incompatible pollen had no significant effect on seed set when compared with the controls. Clogging was only observed in the long-styled morph when one anther of compatible pollen was applied to stigmas 1.5 and 3.0 h after pollination with five anthers of incompatible pollen. The clogging of stigmas by incompatible pollen seems unlikely to have played a major role in the evolution and maintenance of distyly in Turnera ulmifolia.

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Bortezomib Induces Thrombocytopenia by Inhibiting Proplatelet Formation but Not Proliferation and Endomitosis in Human Primary Megakaryocytes

Blood ◽

10.1182/blood.v112.11.87.87 ◽

2008 ◽

Vol 112 (11) ◽

pp. 87-87

Author(s):

Wataru Nogami ◽

Akiko Yamane ◽

Takanori Nakamura ◽

Eri Matsuki ◽

Yasuo Ikeda ◽

...

Keyword(s):

Colony Formation ◽

Proteasome Inhibitors ◽

Human Platelets ◽

Cytotoxic Agents ◽

In Vitro Assays ◽

Inhibitory Effects ◽

Hematopoietic Stem ◽

Proplatelet Formation ◽

Releasing Process

Abstract The proteasome inhibitor bortezomib has therapeutic activity in patients with multiple myeloma. The most common adverse event from its application is thrombocytopenia, which has kinetics that differ from those induced by other cytotoxic agents. After treatment with bortezomib, platelet counts usually decrease within a couple of days but rapidly recover toward baseline during the rest periods between each cycle. The lowest count of platelets in each cycle does not worsen during the 8 courses of bortezomib treatment. Furthermore, bortezomib does not induce any cytotoxic injury in megakaryocyte in the murine model. Therefore, we postulated that bortezomib-induced thrombocytopenia is caused by inhibition of the platelet releasing process without megakaryocyte toxicity. In vitro assays using human bone marrow-derived CD34-positive hematopoietic stem cells revealed that bortezomib did not inhibit colony formation and endomitosis of human primary megakaryocytes in the presence of recombinant human thrombopoietin (rhTPO). As proplatelet formation (PPF) is often used as the indicator of the platelet releasing process in vitro, we evaluated the inhibitory effects of bortezomib for PPF. Seven days after culture of human CD34-postive cells with 10 ng/ml rhTPO, mature megakaryocytes were enriched by discontinuous bovine serum albumin gradients (purity>90%). The enriched mature megakaryocytes were treated with various concentrations of bortezomib for a further 4 days and the percentage of megakaryocytes bearing PPF was calculated under a microscope. Bortezomib dose-dependently inhibited PPF from mature megakaryocytes. Other proteasome inhibitors such as lactacystin and MG132 also demonstrated inhibitory effects on PPF without inhibiting colony formation of megakaryocytes. Since the inhibition of transcriptional factor NF-kB activity is one of the major pathways of proteasome inhibitors, we evaluated the effects of NF-kB inhibitors such as (−)-DHMEQ and Bay11-7082. Both of these inhibitors also demonstrated inhibitory effects on PPF but did not inhibit the colony formation of megakaryocytes. To exclude the direct effects of bortezomib on human platelets, we analyzed the effects of bortezomib for the activation of caspase-3 and mitochondrial potential in human platelets. We found that bortezomib did not directly induce apoptosis in human platelets. Our results demonstrate that bortezomib induces thrombocytopenia by inhibiting PPF but does not affect proliferation of megakaryocytes, endomitosis and platelet apoptosis. We believe this is the first report using human primary megakaryocytes to clarify the pathogenesis of thrombocytopenia caused by bortezomib therapy.

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Synthesis of Novel Chitin Derivatives Bearing Amino Groups and Evaluation of Their Antifungal Activity

Marine Drugs ◽

10.3390/md16100380 ◽

2018 ◽

Vol 16 (10) ◽

pp. 380

Author(s):

Jingjing Zhang ◽

Fang Luan ◽

Qing Li ◽

Guodong Gu ◽

Fang Dong ◽

...

Keyword(s):

Antifungal Activity ◽

Inhibition Zone ◽

Diffusion Method ◽

Inhibitory Effects ◽

Amino Groups ◽

Disk Diffusion Method ◽

Elemental Analyses ◽

Ft Ir ◽

Chitin Derivatives

Chemical modification is one of the most effective methods to improve the biological activity of chitin. In the current study, we modified C3-OH and C6-OH of chitin (CT) and successfully synthesized 6-amino-chitin (NCT) and 3,6-diamino-chitin (DNCT) through a series of chemical reactions. The structure of NCT and DNCT were characterized by elemental analyses, FT-IR, 13C NMR, XRD, and SEM. The inhibitory effects of CT, NCT, and DNCT against six kinds of phytopathogen (F. oxysporum f. sp. cucumerium, B. cinerea, C. lagenarium, P. asparagi, F. oxysporum f. niveum, and G. zeae) were evaluated using disk diffusion method in vitro. Meanwhile, carbendazim and amphotericin B were used as positive controls. Results revealed that 6-amino-chitin (NCT) and 3,6-diamino-chitin (DNCT) showed improved antifungal properties compared with pristine chitin. Moreover, DNCT exhibited the better antifungal property than NCT. Especially, while the inhibition zone diameters of NCT are ranged from 11.2 to 16.3 mm, DNCT are about 11.4–20.4 mm. These data demonstrated that the introduction of amino group into chitin derivatives could be key to increasing the antifungal activity of such compounds, and the greater the number of amino groups in the chitin derivatives, the better their antifungal activity was.

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Biomimetic Approaches for the Development of New Antifouling Solutions: Study of Incorporation of Macroalgae and Sponge Extracts for the Development of New Environmentally-Friendly Coatings

International Journal of Molecular Sciences ◽

10.3390/ijms20194863 ◽

2019 ◽

Vol 20 (19) ◽

pp. 4863 ◽

Cited By ~ 5

Author(s):

Ilse Sánchez-Lozano ◽

Claudia Judith Hernández-Guerrero ◽

Mauricio Muñoz-Ochoa ◽

Claire Hellio

Keyword(s):

Biofilm Formation ◽

Gulf Of California ◽

Environmentally Friendly ◽

In Vitro Assays ◽

Economic Losses ◽

Maritime Industry ◽

Marine Biotechnology ◽

La Paz ◽

Selection Of

Biofouling causes major economic losses in the maritime industry. In our site study, the Bay of La Paz (Gulf of California), biofouling on immersed structures is a major problem and is treated mostly with copper-based antifouling paints. Due to the known environmental effect of such treatments, the search for environmentally friendly alternatives in this zone of high biodiversity is a priority to ensure the conservation and protection of species. The aim of this work was to link chemical ecology to marine biotechnology: indeed, the natural defense of macroalgae and sponge was evaluated against biofoulers (biofilm and macrofoulers) from the same geographical zone, and some coatings formulation was done for field assays. Our approach combines in vitro and field bioassays to ensure the selection of the best AF agent prospects. The 1st step consisted of the selection of macroalgae (5 species) and sponges (2 species) with surfaces harboring a low level of colonizers; then extracts were prepared and assayed for toxicity against Artemia, activity towards key marine bacteria involved in biofilm formation in the Bay of La Paz, and the potency to inhibit adhesion of macroorganisms (phenoloxidase assays). The most active and non-toxic extracts were further studied for biofouling activity in the adhesion of the bacteria involved in biofilm formation and through incorporation in marine coatings which were immersed in La Paz Bay during 40 days. In vitro assays demonstrated that extracts of Laurencia gardneri, Sargassum horridum (macroalgae), Haliclona caerulea and Ircinia sp. (sponges) were the most promising. The field test results were of high interest as the best formulation were composed of extracts of H. caerulea and S. horridum and led to a reduction of 32% of biofouling compared with the control.

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Evaluation of cannabidiol’s inhibitory effect on alpha-glucosidase and its stability in simulated gastric and intestinal fluids

Journal of Cannabis Research ◽

10.1186/s42238-021-00077-x ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Hang Ma ◽

Huifang Li ◽

Chang Liu ◽

Navindra P. Seeram

Keyword(s):

Molecular Docking ◽

High Performance ◽

Inhibitory Effect ◽

In Vitro Assays ◽

Inhibitory Effects ◽

In Vivo Models ◽

Glucosidase Activity ◽

Intestinal Fluids

Abstract Objective Cannabidiol (CBD) has been reported to have anti-diabetic effects in pre-clinical and clinical studies but its inhibitory effects on α-glucosidase, a carbohydrate hydrolyzing enzyme, remain unknown. Herein, we evaluated CBD’s inhibitory effects on α-glucosidase using in vitro assays and computational studies. Methods CBD’s inhibitory effect on α-glucosidase activity was evaluated in a yeast enzymatic assay and by molecular docking. The stability of CBD in simulated gastric and intestinal fluids was evaluated by high-performance liquid chromatography analyses. Results CBD, at 10, 19, 38, 76, 152, 304, 608, and 1216 μM, inhibited α-glucosidase activity with inhibition of 17.1, 20.4, 48.1, 56.6, 59.1, 63.7, 74.1, and 95.4%, respectively. Acarbose, the positive control, showed a comparable inhibitory activity (with 85.1% inhibition at 608 μM). CBD’s inhibitory effect on α-glucosidase was supported by molecular docking showing binding energy (-6.39 kcal/mol) and interactions between CBD and the α-glucosidase protein. CBD was stable in simulated gastric and intestinal fluids for two hours (maintained ≥ 90.0%). Conclusions CBD showed moderate inhibitory effect against yeast α-glucosidase activity and was stable in gastric and intestinal fluids. However, further studies on CBD’s anti-α-glucosidase effects using cellular and in vivo models are warranted to support its potential application for the management of type II diabetes mellitus.

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Point Mutations and Cytochrome P450 Can Contribute to Resistance to ACCase-Inhibiting Herbicides in Three Phalaris Species

Plants ◽

10.3390/plants10081703 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1703

Author(s):

José G. Vázquez-García ◽

Joel Torra ◽

Candelario Palma-Bautista ◽

Ricardo Alcántara-de la Cruz ◽

Rafael De Prado

Keyword(s):

Point Mutations ◽

Resistance Mechanisms ◽

Target Site ◽

In Vitro Assays ◽

Cross Resistance ◽

Northern Iran ◽

Target Site Resistance ◽

Acetyl Coenzyme A Carboxylase ◽

Selection Of

Species of Phalaris have historically been controlled by acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicides; however, overreliance on herbicides with this mechanism of action has resulted in the selection of resistant biotypes. The resistance to ACCase-inhibiting herbicides was characterized in Phalaris brachystachys, Phalaris minor, and Phalaris paradoxa samples collected from winter wheat fields in northern Iran. Three resistant (R) biotypes, one of each Phalaris species, presented high cross-resistance levels to diclofop-methyl, cycloxydim, and pinoxaden, which belong to the chemical families of aryloxyphenoxypropionates (FOPs), cyclohexanediones (DIMs), and phenylpyrazolines (DENs), respectively. The metabolism of 14C-diclofop-methyl contributed to the resistance of the P. brachystachys R biotype, while no evidence of herbicide metabolism was found in P. minor or P. paradoxa. ACCase in vitro assays showed that the target sites were very sensitive to FOP, DIM, and DEN herbicides in the S biotypes of the three species, while the R Phalaris spp. biotypes presented different levels of resistance to these herbicides. ACCase gene sequencing confirmed that cross-resistance in Phalaris species was conferred by specific point mutations. Resistance in the P. brachystachys R biotype was due to target site and non-target-site resistance mechanisms, while in P. minor and P. paradoxa, only an altered target site was found.

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In silico ADME in drug design – enhancing the impact

ADMET & DMPK ◽

10.5599/admet.6.1.470 ◽

2018 ◽

Vol 6 (1) ◽

pp. 15 ◽

Cited By ~ 3

Author(s):

Susanne Winiwarter ◽

Ernst Ahlberg ◽

Edmund Watson ◽

Ioana Oprisiu ◽

Mickael Mogemark ◽

...

Keyword(s):

In Silico ◽

In Vitro Assays ◽

Lead Compounds ◽

Human Dose ◽

Pharmacokinetic Properties ◽

In Silico Predictions ◽

In Silico Models ◽

The Impact ◽

Selection Of

<p>Each year the pharmaceutical industry makes thousands of compounds, many of which do not meet the desired efficacy or pharmacokinetic properties, describing the absorption, distribution, metabolism and excretion (ADME) behavior. Parameters such as lipophilicity, solubility and metabolic stability can be measured in high throughput in vitro assays. However, a compound needs to be synthesized in order to be tested. In silico models for these endpoints exist, although with varying quality. Such models can be used before synthesis and, together with a potency estimation, influence the decision to make a compound. In practice, it appears that often only one or two predicted properties are considered prior to synthesis, usually including a prediction of lipophilicity. While it is important to use all information when deciding which compound to make, it is somewhat challenging to combine multiple predictions unambiguously. This work investigates the possibility of combining in silico ADME predictions to define the minimum required potency for a specified human dose with sufficient confidence. Using a set of drug discovery compounds,in silico predictions were utilized to compare the relative ranking based on minimum potency calculation with the outcomes from the selection of lead compounds. The approach was also tested on a set of marketed drugs and the influence of the input parameters investigated.</p>

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