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1.
Acta toxicol. argent ; 28(1): 19-22, Apr. 2020. graf
Article in Spanish | LILACS | ID: biblio-1248665

ABSTRACT

Resumen La micrografía analítica es una herramienta útil para la identificación de restos vegetales en muestras de material trozado o molido que no podrían ser identificadas de forma morfológica. El objetivo de este estudio es conocer los caracteres mi- crográficos de las semillas de Cebil (Anadenanthera colubrina var. cebil (Griseb.) Altschul, Leguminosae) y Chamico (Datura ferox L., Solanaceae), con el fin de proporcionar parámetros empleables para su identificación en un contexto forense y toxicológico. Los caracteres micrográficos relacionados con el tegumento exterior y las esclereidas fueron los más indicados para diferenciar entre ambas especies.


Abstract Analytical micrography is a useful tool for the identification of plant parts that can't be identified for its morphological characters. The aim of this work is to obtain micrographic characters of Cebil (Anadenanthera colubrina var. cebil (Griseb.) Altschul, Leguminosae) and Chamico (Datura ferox L., Solanaceae) seeds for its identification in a toxicological and forensic context. The most suitable micrographic features were the ones related with exterior testa and the stone cells.


Subject(s)
Seeds/cytology , Solanaceae/cytology , Hallucinogens , Fabaceae/cytology , Argentina , Plant Poisoning/diagnosis , Photomicrography/methods
2.
BMC Biotechnol ; 20(1): 15, 2020 03 12.
Article in English | MEDLINE | ID: mdl-32164664

ABSTRACT

BACKGROUND: Infections caused by fungi are often refractory to conventional therapies and urgently require the development of novel options, such as immunotherapy. To produce therapeutic antibodies, a plant-based expression platform is an attractive biotechnological strategy compared to mammalian cell cultures. In addition to whole plants, hairy roots (HR) cultures can be used, representing an expression system easy to build up, with indefinite growth while handled under containment conditions. RESULTS: In this study the production in HR of a recombinant antibody, proved to be a good candidate for human immunotherapy against fungal infections, is reported. Expression and secretion of this antibody, in an engineered single chain (scFvFc) format, by HR from Nicotiana benthamiana and Solanum lycopersicum have been evaluated with the aim of directly using the deriving extract or culture medium against pathogenic fungi. Although both Solanaceae HR showed good expression levels (up to 68 mg/kg), an optimization of rhizosecretion was only obtained for N. benthamiana HR. A preliminary assessment to explain this result highlighted the fact that not only the presence of proteases, but also the chemical characteristics of the growth medium, can influence antibody yield, with implications on recombinant protein production in HR. Finally, the antifungal activity of scFvFc 2G8 antibody produced in N. benthamiana HR was evaluated in Candida albicans growth inhibition assays, evidencing encouraging results. CONCLUSIONS: Production of this anti-fungal antibody in HR of N. benthamiana and S. lycopersicum elucidated factors affecting pharming in this system and allowed to obtain promising ready-to-use immunotherapeutics against C. albicans.


Subject(s)
Antifungal Agents/pharmacology , Candida albicans/growth & development , Single-Chain Antibodies/pharmacology , Solanaceae/cytology , Candida albicans/drug effects , Homologous Recombination , Solanum lycopersicum/cytology , Solanum lycopersicum/genetics , Plant Roots/cytology , Plant Roots/genetics , Plants, Genetically Modified , Protein Engineering , Recombinant Proteins/pharmacology , Single-Chain Antibodies/genetics , Solanaceae/genetics , Nicotiana/cytology , Nicotiana/genetics
3.
Proc Natl Acad Sci U S A ; 115(23): 6028-6033, 2018 06 05.
Article in English | MEDLINE | ID: mdl-29784796

ABSTRACT

The morning glory family, Convolvulaceae, is globally important in medicine and food crops. The family has worldwide distribution in a variety of habitats; however, its fossil record is very poorly documented. The current fossil record suggests an origin in North America, which is in contrast to molecular data that indicate an East Gondwana origin. We report Ipomoea leaves from the late Paleocene (Thanetian; 58.7-55.8 million years ago) of India, which was a part of East Gondwana during this time. This is the earliest fossil record for both the family Convolvulaceae and the order Solanales. This suggests that the sister families Convolvulaceae and Solanaceae diverged before the Eocene in Gondwana-derived continents. The evidence presented here supports the conclusion from molecular phylogenetic analysis of an East Gondwana origin of Convolvulaceae.


Subject(s)
Convolvulaceae/cytology , Ipomoea/cytology , Evolution, Molecular , Fossils , India , Phylogeny , Phylogeography/methods , Plant Leaves/cytology , Plant Leaves/metabolism , Solanaceae/cytology
4.
New Phytol ; 214(4): 1657-1672, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28386988

ABSTRACT

Pathogen-associated molecular patterns (PAMPs) are detected by plant pattern recognition receptors (PRRs), which gives rise to PAMP-triggered immunity (PTI). We characterized a novel fungal PAMP, Cell Death Inducing 1 (RcCDI1), identified in the Rhynchosporium commune transcriptome sampled at an early stage of barley (Hordeum vulgare) infection. The ability of RcCDI1 and its homologues from different fungal species to induce cell death in Nicotiana benthamiana was tested following agroinfiltration or infiltration of recombinant proteins produced by Pichia pastoris. Virus-induced gene silencing (VIGS) and transient expression of Phytophthora infestans effectors PiAVR3a and PexRD2 were used to assess the involvement of known components of PTI in N. benthamiana responses to RcCDI1. RcCDI1 was highly upregulated early during barley colonization with R. commune. RcCDI1 and its homologues from different fungal species, including Zymoseptoria tritici, Magnaporthe oryzae and Neurospora crassa, exhibited PAMP activity, inducing cell death in Solanaceae but not in other families of dicots or monocots. RcCDI1-triggered cell death was shown to require N. benthamiana Brassinosteroid insensitive 1-Associated Kinase 1 (NbBAK1), N. benthamiana suppressor of BIR1-1 (NbSOBIR1) and N. benthamiana SGT1 (NbSGT1), but was not suppressed by PiAVR3a or PexRD2. We report the identification of a novel Ascomycete PAMP, RcCDI1, recognized by Solanaceae but not by monocots, which activates cell death through a pathway that is distinct from that triggered by the oomycete PAMP INF1.


Subject(s)
Ascomycota/pathogenicity , Fungal Proteins/metabolism , Host-Pathogen Interactions/physiology , Pathogen-Associated Molecular Pattern Molecules/metabolism , Solanaceae/microbiology , Amino Acid Sequence , Ascomycota/genetics , Ascomycota/physiology , Cell Death , Conserved Sequence , Fungal Proteins/genetics , Hordeum/microbiology , Phylogeny , Plant Cells/microbiology , Plant Proteins/genetics , Plant Proteins/metabolism , Solanaceae/cytology , Nicotiana/genetics , Nicotiana/microbiology , Virulence Factors/genetics , Virulence Factors/metabolism
5.
Bioresour Technol ; 187: 326-330, 2015.
Article in English | MEDLINE | ID: mdl-25863210

ABSTRACT

Energy consumption and water resource in the cultivation and harvesting steps still need to be minimized for the popularization of the microalgae-based products. An efficient electro-flocculation method for harvesting Dunaliella Salina integrated with local sand has been successfully applied. Sand was effective for speeding up the processes of flocculation and sedimentation of algal flocs and the electrolytic hydroxides was essential to bridge the sand and small flocs into large dense flocs. The maximal recovery effective improved from 95.13% in 6min to 98.09% in 4.5min and the optimal electrical energy consumption decreased 51.03% compared to conventional electro-flocculation in a laboratory ambient condition. Furthermore, reusing the flocculated medium in cultivation of the D. Salina with nitrogen supplemented performed no worse than using fresh medium. This sand enhanced electro-flocculation (SEF) technology provides a great potential for saving time and energy associated with improving microalgae harvesting.


Subject(s)
Electrochemistry/methods , Flocculation , Soil/chemistry , Solanaceae/cytology , Solanaceae/physiology , Cost-Benefit Analysis , Energy Transfer
6.
Phytochem Anal ; 25(1): 29-35, 2014.
Article in English | MEDLINE | ID: mdl-23839972

ABSTRACT

INTRODUCTION: Hyoscyamine and scopolamine, anti-cholinergic agents widely used in medicine, are typically obtained from plants grown under natural conditions. Since field cultivation entails certain difficulties (changeable weather, pests, etc.), attempts have been made to develop a plant in vitro culture system as an alternative source for the production of these compounds. During experiments to locate the limiting steps in the biotechnological procedure, it is important to monitor not only the levels of the final products but also the changes in the concentration of their precursors. OBJECTIVE: To develop a HPTLC method for the separation and quantitation of the main tropane alkaloids hyoscyamine and scopolamine, their respective direct precursors littorine and anisodamine, and cuscohygrine, a product of a parallel biosynthetic pathway that shares a common precursor (N-methyl-∆(1) -pyrrolium cation) with tropane alkaloids. METHODS: Using alkaloid extracts from Atropa baetica hairy roots, different TLC chromatographic systems and developing procedures were investigated. RESULTS: Full separation of all compounds was obtained on HPTLC Si60 F254 plates preconditioned with mobile phase vapours (chloroform:methanol:acetone:25% ammonia ratios of 75:15:10:1.8, v/v/v/v). The chromatograms were developed twice (at distances of 4.0 and 3.0 cm) in a Camag twin trough chamber and visualised with Dragendorff's reagent. Densitometric detection (λ = 190 and 520 nm) was used for quantitative analyses of the different plant samples. CONCLUSION: This method can be recommended for quantitation of hyoscyamine, scopolamine, anisodamine, littorine and cuscohygrine in different plant material (field grown vs. in vitro cultures).


Subject(s)
Atropine Derivatives/analysis , Chromatography, Thin Layer/methods , Hyoscyamine/analysis , Scopolamine/analysis , Solanaceae/chemistry , Solanaceous Alkaloids/analysis , Acetone/analogs & derivatives , Acetone/analysis , Atropa/chemistry , Atropa/metabolism , Atropine Derivatives/metabolism , Plant Roots/chemistry , Plant Roots/cytology , Plant Roots/metabolism , Pyrrolidines/analysis , Reproducibility of Results , Solanaceae/cytology , Solanaceae/metabolism , Solanaceous Alkaloids/metabolism , Tissue Culture Techniques
7.
Plant Physiol ; 160(3): 1551-66, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22961130

ABSTRACT

In some species, a crucial role has been demonstrated for the seed endosperm during germination. The endosperm has been shown to integrate environmental cues with hormonal networks that underpin dormancy and seed germination, a process that involves the action of cell wall remodeling enzymes (CWREs). Here, we examine the cell wall architectures of the endosperms of two related Brassicaceae, Arabidopsis (Arabidopsis thaliana) and the close relative Lepidium (Lepidium sativum), and that of the Solanaceous species, tobacco (Nicotiana tabacum). The Brassicaceae species have a similar cell wall architecture that is rich in pectic homogalacturonan, arabinan, and xyloglucan. Distinctive features of the tobacco endosperm that are absent in the Brassicaceae representatives are major tissue asymmetries in cell wall structural components that reflect the future site of radicle emergence and abundant heteromannan. Cell wall architecture of the micropylar endosperm of tobacco seeds has structural components similar to those seen in Arabidopsis and Lepidium endosperms. In situ and biomechanical analyses were used to study changes in endosperms during seed germination and suggest a role for mannan degradation in tobacco. In the case of the Brassicaceae representatives, the structurally homogeneous cell walls of the endosperm can be acted on by spatially regulated CWRE expression. Genetic manipulations of cell wall components present in the Arabidopsis seed endosperm demonstrate the impact of cell wall architectural changes on germination kinetics.


Subject(s)
Brassicaceae/anatomy & histology , Brassicaceae/cytology , Cell Wall/chemistry , Endosperm/anatomy & histology , Endosperm/cytology , Solanaceae/anatomy & histology , Solanaceae/cytology , Arabidopsis/anatomy & histology , Arabidopsis/cytology , Cellulose/metabolism , Endosperm/growth & development , Germination , Lepidium sativum/anatomy & histology , Lepidium sativum/cytology , Mannans/metabolism , Monosaccharides/chemistry , Mutation/genetics , Pectins/metabolism , Nicotiana/anatomy & histology , Nicotiana/cytology
8.
New Phytol ; 195(4): 894-911, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22738163

ABSTRACT

The pathogenicity of the Gram-negative plant-pathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv) is dependent on type III effectors (T3Es) that are injected into plant cells by a type III secretion system and interfere with cellular processes to the benefit of the pathogen. In this study, we analyzed eight T3Es from Xcv strain 85-10, six of which were newly identified effectors. Genetic studies and protoplast expression assays revealed that XopB and XopS contribute to disease symptoms and bacterial growth, and suppress pathogen-associated molecular pattern (PAMP)-triggered plant defense gene expression. In addition, XopB inhibits cell death reactions induced by different T3Es, thus suppressing defense responses related to both PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). XopB localizes to the Golgi apparatus and cytoplasm of the plant cell and interferes with eukaryotic vesicle trafficking. Interestingly, a XopB point mutant derivative was defective in the suppression of ETI-related responses, but still interfered with vesicle trafficking and was only slightly affected with regard to the suppression of defense gene induction. This suggests that XopB-mediated suppression of PTI and ETI is dependent on different mechanisms that can be functionally separated.


Subject(s)
Bacterial Proteins/metabolism , Bacterial Secretion Systems/genetics , Plant Immunity , Xanthomonas campestris/metabolism , Arabidopsis/genetics , Arabidopsis/immunology , Arabidopsis/microbiology , Bacterial Proteins/genetics , Cell Death , Gene Expression Regulation, Bacterial , Gene Expression Regulation, Plant , Genes, Bacterial/genetics , Genetic Association Studies , Golgi Apparatus/metabolism , Plant Cells/microbiology , Plant Immunity/genetics , Plant Proteins/metabolism , Protein Transport/genetics , Solanaceae/cytology , Solanaceae/microbiology , Virulence/genetics , Xanthomonas campestris/genetics , Xanthomonas campestris/pathogenicity
9.
J Plant Physiol ; 169(10): 940-8, 2012 Jul 01.
Article in English | MEDLINE | ID: mdl-22551956

ABSTRACT

Plant hormones direct many processes of floral and post-floral morphogenesis in Angiosperms. However, their role in shaping floral morphological novelties, such as inflated calyx syndrome (ICS) exhibited by a few genera of the Solanaceae, remains unknown. In Withania and Physalis, sepals resume growth after pollination and encapsulate the mature fruit to form a balloon-like structure, i.e. ICS. The epidermal cells of calyx show enlargement and lobation post-fertilization. Application of hormones to depistillated flower buds of Withania revealed that cytokinins and gibberellins mimic fertilization signals. The ICS development is a synchronous step with fruit development; both processes are under the control of more or less the same set of hormones, including cytokinins and gibberellic acids. Interestingly, inhibition of ethylene in the system is sufficient to yield inflated calyx in Withania. In contrast, Tubocapsicum, a closely related species and an evolutionary natural loss mutant of ICS - showed no response to applied hormones, and ethylene led to inflation of the receptacle indirectly. In addition to hormones, the expression of an MPF2-like MADS-box transcription factor in sepals is essential for ICS formation. Nevertheless, the interactions between MPF2-like genes and hormones are barely detectable at the transcript level. Our data provide insight into the role of hormones in generating floral morphological diversity during evolution.


Subject(s)
Ethylenes/metabolism , Flowers/anatomy & histology , Plant Growth Regulators/metabolism , Solanaceae/anatomy & histology , Cell Differentiation/drug effects , Cell Differentiation/genetics , Cytokinins/metabolism , Ethylenes/pharmacology , Fertilization/drug effects , Flowers/cytology , Flowers/physiology , Flowers/ultrastructure , Fruit/drug effects , Fruit/physiology , Gene Expression Regulation, Plant/drug effects , Genes, Plant/genetics , Gibberellins/metabolism , Models, Biological , Plant Epidermis/cytology , Plant Epidermis/ultrastructure , Plant Growth Regulators/pharmacology , Plant Proteins/genetics , Plant Proteins/metabolism , Pollination/physiology , Signal Transduction/drug effects , Signal Transduction/genetics , Solanaceae/cytology , Solanaceae/physiology , Solanaceae/ultrastructure , Species Specificity , Withania/anatomy & histology , Withania/cytology , Withania/physiology , Withania/ultrastructure
10.
Biotechniques ; 52(1): 31-7, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22229725

ABSTRACT

In this study, we have developed a robust cryohistological method that allows imaging of virtually any type of plant cell or tissue while preserving fluorescent protein signals and maintaining excellent cellular and subcellular morphology. This method involves modified fixation of plant tissues (i.e., leaves, stems, and petioles), infiltration in a sucrose gradient, freezing, and collection of cryosections directly onto a cryoadhesive tape. Using this method followed by microscopic analysis, we demonstrated a localized accumulation of green fluorescent protein (GFP) in Nicotiana benthamiana plants agroinfiltrated with the movement-incompetent tobacco mosaic virus-based vector and systemic accumulation of GFP in plants infiltrated with the movement-competent vector. Overall, this simple cryohistological procedure reduced sample preparation time and allowed processing of tissue sections for high-resolution imaging of targeted fluorescent proteins in all plant tissues.


Subject(s)
Cryoultramicrotomy/methods , Green Fluorescent Proteins/metabolism , Nicotiana/metabolism , Solanaceae/cytology , Green Fluorescent Proteins/analysis , Plant Cells/metabolism , Plant Leaves/cytology , Plant Leaves/metabolism , Plant Stems/cytology , Plant Stems/metabolism , Plants, Genetically Modified/genetics , Plants, Genetically Modified/metabolism , Solanaceae/metabolism , Solanaceae/virology , Tissue Fixation , Tobacco Mosaic Virus/genetics
11.
Mol Biol Evol ; 28(1): 793-801, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20855430

ABSTRACT

The plant genus Lycium (Solanaceae) originated in the Americas and includes approximately 85 species that are distributed worldwide. The vast majority of Old World species occur in southern Africa and eastern Asia. In this study, we examine biogeographic relationships among Old World species using a phylogenetic approach coupled with molecular evolutionary analyses of the S-RNase self-incompatibility gene. The phylogeny inferred from nuclear granule-bound starch synthase I (GBSSI), nuclear conserved ortholog set II (COSII) marker C2_At1g24360, and plastid spacer data (trnH-pbsA, trnD(GUC)-trnT(GGU), rpl32-trnL(UAG), and ndhF-rpl32) includes a clade of eastern Asian Lycium nested within the African species, suggesting initial dispersal from the Americas to Africa, with subsequent dispersal to eastern Asia. Molecular dating estimates suggest that these dispersal events occurred relatively recently, with dispersal from the Americas to Africa approximately 3.64 Ma (95% highest posterior density [HPD]: 1.58-6.27), followed by subsequent dispersal to eastern Asia approximately 1.21 Ma (95% HPD: 0.32-2.42). In accordance, the S-RNase genealogy shows that S-RNases isolated from Old World species are restricted to four lineages, a subset of the 14 lineages including S-RNases isolated from New World Lycium species, supporting a bottleneck of S-RNase alleles concomitant with a single dispersal event from the Americas to the Old World. Furthermore, the S-RNase genealogy is also consistent with dispersal of Lycium from Africa to Asia, as eastern Asian alleles are restricted to a subset of the lineages that also include African alleles. Such a multilocus approach, including complementary data from GBSSI, COSII, plastid spacer regions, and S-RNase, is powerful for understanding dispersal histories of closely related species.


Subject(s)
Biological Evolution , Cell Nucleus/genetics , DNA, Plant/genetics , Plastids/genetics , Ribonucleases/genetics , Solanaceae/genetics , Africa , Americas , Asia , Molecular Sequence Data , Phylogeny , Pollination , Sequence Analysis, DNA , Solanaceae/classification , Solanaceae/cytology
12.
Yi Chuan ; 30(11): 1506-12, 2008 Nov.
Article in Chinese | MEDLINE | ID: mdl-19073561

ABSTRACT

Nucleotide substitution and indels (insertions and deletions) events are the major evolutionary driving forces. Comparisons of the indels and nucleotide substitution patterns were made in the chloroplast genomes between Solanum lycopersicum L. and Solanum bulbocastanum L., Nicotiana tomentosiformis L. and Nicotiana tabacum L. in Solanaceae. The influence of mutation on genome composition was analyzed. The indels and substitutions were not randomly distributed throughout the chloroplast genomes. The indels were in AT-rich regions. One base pair indels accounted for above 30% of the total indels. Most of the indels were short of 10 bp. The nucleotide substitutions showed Ts/Tv bias, but transversion frequency of T-->G and A-->C was increased significantly. Ts/Tv rates were lineage-specific. The Ts/Tv rate between S. lycopersicum and S. bulbocastanum was lower than that between N. tomentosiformis and N. tabacum. (A+T)/(G+C) rates varied in different lineages, which had an influence on (G+C)% of genomes. The changes in the (A+T)/(G+C) rates might correlate with the life histories of different species.


Subject(s)
Chloroplasts/genetics , Genome, Plant/genetics , INDEL Mutation , Nucleotides/genetics , Solanaceae/cytology , Solanaceae/genetics , Genomics , Species Specificity
13.
Fen Zi Xi Bao Sheng Wu Xue Bao ; 41(6): 489-94, 2008 Dec.
Article in Chinese | MEDLINE | ID: mdl-19137821

ABSTRACT

Viable egg cells of Brugmansia aurea Lagerh "Goildens Kornett" were isolated using mechanical dissection and enzymic digestion. The ovules were cut from middle part and pushed its micropylar position using a dissection needle. Generally the three cells of egg apparatus were released from cut end of ovule. When the ovules put an isolating solution only containing 0.04% CaCl2, 1% BSA and 12% mannitol, 7 egg apparatus could be isolated from 40 ovules within 2 h. However, it is some difficult to separate egg cell from two synergids. When ovules were first incubated in an enzymic solution containing 1% Pectinase (Serva), 1% Cellulase (Onozuka RS) and 12% mannitol for 30 min, and then transferred into the above-mentioned isolating solution to dissect, 8 egg apparatus could be isolated from 40 ovules within 2h and egg cell is easy to separate from two synergids. The isolated egg cells of Brugmansia aurea Lagerh "Goildens Kornett" could be used in vitro fertilization to explore fertilization mechanism and in egg development using molecular methods.


Subject(s)
Flowers/cytology , Solanaceae/cytology
14.
Bioorg Med Chem ; 13(6): 2015-20, 2005 Mar 15.
Article in English | MEDLINE | ID: mdl-15727855

ABSTRACT

The protective effects of polyacylated anthocyanin, heavenly blue anthocyanin (HBA), in blue flower petals of morning glory (Ipomoea tricolor cv. Heavenly Blue) against UV-B induced DNA damage were examined. We first clarified the concentration of HBA in epidermal vacuoles to be 12mM, and then constructed a UV-B irradiating apparatus resembling flower petal tissue to assess the screening effect of HBA. Monochromatic (280 and 310nm) or broad UV-B induced DNA lesions were reduced completely by the HBA filter to the same molecular numbers as those in living petal epidermis. However, diluted HBA solution and trisdeacyl HBA did not have the same reduction effect. HBA was more tolerant to solar radiation than trisdeacyl HBA. These data strongly suggest that polyacylated anthocyanins in flower petals can screen harmful UV-B efficiently. This action might be largely due to aromatic acyl residues.


Subject(s)
Anthocyanins/chemistry , Anthocyanins/physiology , Flowers/chemistry , Flowers/radiation effects , Solanaceae/chemistry , Solanaceae/radiation effects , Ultraviolet Rays/adverse effects , Acylation , Color , DNA Damage/radiation effects , Flowers/cytology , Hydrogen-Ion Concentration , Molecular Structure , Plant Epidermis/chemistry , Solanaceae/cytology
15.
Tsitologiia ; 46(8): 685-9, 2004.
Article in Russian | MEDLINE | ID: mdl-15598013

ABSTRACT

Three mechanisms of fused spindle formation in meiosis of Solanacea have been described: 1) approach of daughter nuclei at prophase II; 2) fusion of perinuclear cytoskeleton systems at prophase II; 3) approach and fusion of prometaphase chaotic figures at prometaphase II. The process of fusion spindle formation appears to be complex and including several steps.


Subject(s)
Cytoskeleton/physiology , Solanaceae/physiology , Spindle Apparatus/physiology , Solanum lycopersicum/cytology , Meiosis , Metaphase , Solanaceae/cytology , Solanaceae/ultrastructure
16.
Plant Physiol ; 132(4): 1728-38, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12913131

ABSTRACT

We tested whether signaling pathways induced by systemin, oligosaccharide elicitors (OEs), and ultraviolet (UV)-B radiation share common components in Lycopersicon peruvianum suspension-cultured cells. These stress signals all induce mitogen-activated protein kinase (MAPK) activity. In desensitization assays, we found that pretreatment with systemin and OEs transiently reduced the MAPK response to a subsequent treatment with the same or a different elicitor. In contrast, MAPK activity in response to UV-B increased after pretreatment with systemin and OEs. These experiments demonstrate the presence of signaling components that are shared by systemin, OEs, and UV-B. Based on desensitization assays, it is not clear if the same or different MAPKs are activated by different stress signals. To identify specific stress-responsive MAPKs, we cloned three MAPKs from a tomato (Lycopersicon esculentum) leaf cDNA library, generated member-specific antibodies, and performed immunocomplex kinase assays with extracts from elicited L. peruvianum cells. Two highly homologous MAPKs, LeMPK1 and LeMPK2, were activated in response to systemin, four different OEs, and UV-B radiation. An additional MAPK, LeMPK3, was only activated by UV-B radiation. The common activation of LeMPK1 and LeMPK2 by many stress signals is consistent with the desensitization assays and may account for substantial overlaps among stress responses. On the other hand, MAPK activation kinetics in response to elicitors and UV-B differed substantially, and UV-B activated a different set of LeMPKs than the elicitors. These differences may account for UV-B-specific responses.


Subject(s)
Mitogen-Activated Protein Kinases/metabolism , Oligosaccharides/agonists , Peptides/pharmacology , Solanaceae/drug effects , Solanaceae/radiation effects , Amino Acid Sequence , Cells, Cultured , Cloning, Molecular , Enzyme Activation/radiation effects , Gene Expression Regulation, Plant/drug effects , Gene Expression Regulation, Plant/radiation effects , MAP Kinase Signaling System/drug effects , MAP Kinase Signaling System/radiation effects , Mitogen-Activated Protein Kinases/genetics , Molecular Sequence Data , Oligosaccharides/pharmacology , Solanaceae/cytology , Solanaceae/enzymology , Time Factors , Ultraviolet Rays
18.
Acta Biochim Pol ; 49(3): 775-80, 2002.
Article in English | MEDLINE | ID: mdl-12422246

ABSTRACT

The plant Solanum nigrum treated with the pathogen Phytophthora infestans-derived elicitor responded by elevated reactive oxygen species (ROS) production, lipid peroxidation and lipoxygenase (EC 1.13.11.12) activity in comparison with control plants indicating that oxidative stress took place. We demonstrate that these events are accompanied by a significant increase in plastoquinone (PQ) level. It is postulated that PQ may be associated with mechanisms maintaining a tightly controlled balance between the accumulation of ROS and antioxidant activity that determines the full expression of effective defence.


Subject(s)
Adaptation, Physiological/physiology , Plastoquinone/metabolism , Solanaceae/metabolism , Antioxidants/chemistry , Antioxidants/metabolism , Antioxidants/pharmacology , Lipid Peroxidation/physiology , Lipoxygenase/metabolism , Oxidation-Reduction , Phytophthora/pathogenicity , Plant Diseases/microbiology , Plant Leaves/cytology , Plant Leaves/metabolism , Plant Leaves/microbiology , Plastoquinone/analysis , Plastoquinone/pharmacology , Reactive Oxygen Species/metabolism , Solanaceae/cytology , Solanaceae/microbiology
19.
Genes Dev ; 16(17): 2213-8, 2002 Sep 01.
Article in English | MEDLINE | ID: mdl-12208843

ABSTRACT

Plant shoot development depends on the perpetuation of a group of undifferentiated cells in the shoot apical meristem (SAM). In the Petunia mutant hairy meristem (ham), shoot meristems differentiate postembryonically as continuations of the subtending stem. HAM encodes a putative transcription factor of the GRAS family, which acts non-cell-autonomously from L3-derived tissue of lateral organ primordia and stem provasculature. HAM acts in parallel with TERMINATOR (PhWUSCHEL) and is required for continued cellular response to TERMINATOR and SHOOTMERISTEMLESS (PhSTM). This reveals a novel mechanism by which signals from differentiating tissues extrinsically control stem cell fate in the shoot apex.


Subject(s)
Genes, Plant , Meristem/growth & development , Plant Shoots/growth & development , Solanaceae/growth & development , Solanaceae/genetics , Amino Acid Sequence , Base Sequence , Cell Differentiation , DNA, Plant/genetics , Gene Expression Regulation, Developmental , Gene Expression Regulation, Plant , Meristem/cytology , Molecular Sequence Data , Mutagenesis, Insertional , Plant Proteins/genetics , Plant Shoots/cytology , Plants, Genetically Modified , Sequence Homology, Amino Acid , Signal Transduction , Solanaceae/cytology , Stem Cells/cytology
20.
J Hered ; 93(3): 185-92, 2002.
Article in English | MEDLINE | ID: mdl-12195034

ABSTRACT

We evaluated a 4x accession of Ipomoea batatas (L.) Lam. and four 2x accessions of Ipomoea triloba for 2n pollen production. Approximately 90% of the genotypes of accession 81.2 (I. batatas, 4x) produced 2n pollen with different frequencies. In contrast, none of the genotypes of I. triloba produced 2n pollen. The diameter of the 2n pollen was approximately 30% ((3) sqrt 2) larger than that of the n pollen, making it easy to identify, measure, and quantify. The correlation (r = 0.93**) between the frequency of giant pollen and the frequency of dyads and triads was highly significant, strongly suggesting that the giant pollen grains were 2n pollen. The 2n pollen producers presented either a parallel or tripolar spindle arrangement (Y shaped) at anaphase II instead of the normal 60 degrees crossed spindle orientation. These two abnormal spindle configurations produced dyads and triads, with different frequencies (13-67%), instead of tetrads. Occasionally a metaphase II spindle variation was found with a single fused spindle, which also forms a dyad. The correlation (r = 0.89**) between the frequency of 2n pollen and the frequency of parallel, fused, and tripolar spindle arrangements was also highly significant, suggesting that these abnormal spindle configurations are involved in the production of 2n pollen in I. batatas. When we evaluated the efficiency of 2n pollen in polyploidization using 4x x 4x (2n) crosses, all progenies were 4x, suggesting the existence of barriers to crossability between 4x genotypes and their 2n pollen-producer counterparts.


Subject(s)
Pollen/physiology , Polyploidy , Solanaceae/genetics , Anaphase , Gene Frequency , Pollen/cytology , Pollen/genetics , Solanaceae/cytology
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