scholarly journals Increased tolerance to wheat powdery mildew by heterologous constitutive expression of the Solanum chacoense Snakin-1 gene

2011 ◽  
Vol 47 (Special Issue) ◽  
pp. S135-S141 ◽  
Author(s):  
P. Faccio ◽  
C. Vazquez-Rovere ◽  
E. Hopp ◽  
G. González ◽  
C. Décima-Oneto ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Constitutive Expression ◽  
Erwinia Carotovora ◽  
Transgenic Potato ◽  
Phytopathogenic Fungi ◽  
Solanum Chacoense ◽  
Wheat Powdery Mildew ◽  
Enhanced Resistance ◽  
High Level

Great efforts are currently being devoted to studying the use of transgenes to confer resistance to phytopathogenic fungi. Snakin-1 is a broad-spectrum antimicrobial peptide isolated from Solanum that is active in vitro against bacteria and fungi. Recently, it was reported that overexpression of the snakin-1 (SN1) gene in transgenic potato plants enhanced resistance to Rhizoctonia solani and Erwinia carotovora. In this work wheat transgenic plants that constitutively expressed the S. chacoense SN1 gene were challenged with Blumeria graminis f.sp. tritici. Enhanced resistance to the pathogen was observed in two transgenic lines in which the development of the disease was delayed and reduced compared with the wild type variety ProINTA Federal. An association between high resistance to the pathogen and a high level of snakin-1 transcripts in the plant was observed. This is the first report on SN1 gene expression in Gramineae and its effects on wheat powdery mildew development.

scholarly journals Induction of the Maize GapC4 Promoter in Transgenic Potato under Anaerobiosis and in Erwinia carotovora-Inoculated Tuber Tissue

1999 ◽  
Vol 12 (3) ◽  
pp. 182-188 ◽  
Author(s):  
Lorenz Bülow ◽  
Uwe Köhler ◽  
Rüdiger Cerff ◽  
Reinhard Hehl ◽  
Klaus Düring
Keyword(s):  
Experimental System ◽  
Erwinia Carotovora ◽  
Transgenic Potato ◽  
Intact Tissue ◽  
Induction Pattern ◽  
Pectolytic Enzymes ◽  
Genes Encoding ◽  
Live Bacteria ◽  
Foreign Genes ◽  
High Level

The induction pattern of the GapC4 promoter from maize in transgenic potato has been analyzed by fusion to the β-glucuronidase (gus) gene. Under anaerobic conditions this promoter confers high level expression not only in leaves, stems, and roots but also in tubers. After inoculation of potato tuber disks with Erwinia carotovora subsp. atroseptica, β-glucuronidase (GUS) activity could be detected in macerated tissue as well as in surrounding intact tissue. In mock controls no induction was detected, ruling out any induction due to an overall limitation in oxygen in the experimental system. In addition, it could be proven that no diffusion of GUS protein from macerated into intact tissue occurred. The promoter was shown to be aerobically induced even in the absence of live bacteria by incubation with purified Erwinia spp. pectolytic enzymes alone. Therefore, promoter induction seems to be mediated by a mobile factor instead of by limitation in oxygen. These results demonstrate that the maize GapC4 promoter is suitable for directing foreign genes encoding antibacterial proteins in transgenic potato.

Bactericidal and Fungicidal Activities of Calia secundiflora (Ort.) Yakovlev

2008 ◽  
Vol 63 (9-10) ◽  
pp. 653-657 ◽  
Author(s):  
Dolores Pérez-Laínez ◽  
Rosario García-Mateos ◽  
Ruben San Miguel-Chávez ◽  
Marcos Soto-Hernández ◽  
Enrique Rodríguez-Pérez ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Alternaria Solani ◽  
Erwinia Carotovora ◽  
Phytopathogenic Fungi ◽  
Quinolizidine Alkaloids ◽  
Liquid Chromatography Mass Spectrometry ◽  
In Vitro Bioassay ◽  
Organic Extract ◽  
Phytopathogenic Fungi And Bacteria

Calia secundiflora (Ortega) Yakovlev (Fabaceae) is considered a medicinal plant in Mexico but has scarcely been used because of the toxicity of its quinolizidine alkaloids. Several quinolizidine alkaloids have shown bactericidal, nematicidal, and fungicidal activities. The purpose of this study was to identify the alkaloids in the seeds and evaluate the activity of the organic extract on several phytopathogenic fungi and bacteria. An in vitro bioassay was conducted with species of the following phytopathogenic fungi: Alternaria solani, Fusarium oxysporum and Monilia fructicola; and of the following bacteria Pseudomonas sp., Xanthomonas campestris and Erwinia carotovora. Cytisine, lupinine, anagyrine, sparteine, N-methylcytisine, 5,6-dehydrolupanine, and lupanine were identified by liquid chromatography-mass spectrometry in the extract of seeds; the most abundant compound of the extract was cytisine. It was observed that the crude extract of Calia secundiflora was moderately active on bacteria and more potent on phytopathogenic fungi. In contrast cytisine showed the opposite effects.

scholarly journals Thyroid hormone induces constitutive keratin gene expression during Xenopus laevis development.

1989 ◽  
Vol 9 (5) ◽  
pp. 1823-1831 ◽  
Author(s):  
P M Mathisen ◽  
L Miller
Keyword(s):  
Thyroid Hormone ◽  
Xenopus Laevis ◽  
Constitutive Expression ◽  
High Level Expression ◽  
Keratin Gene ◽  
Explant Cultures ◽  
Extensive Cell ◽  
High Level

We have used in vitro explant cultures of Xenopus laevis skin to investigate the role that the thyroid hormone triiodothyronine (T3) plays in activating the 63-kilodalton (kDa) keratin genes. The activation of these genes in vivo requires two distinct steps, one independent of T3 and one dependent on T3. In this report we have shown that the same two steps are required to fully activate the 63-kDa keratin genes in skin explant cultures, and we have characterized the T3-mediated step in greater detail. Unlike the induction of transcription by T3 or steroid hormones in adult tissues, there was a long latent period of approximately 2 days between the addition of T3 to skin cultures and an increase in concentration of keratin mRNA. While the T3 induction of 63-kDa keratin gene transcription cannot occur until age 48, a short transient exposure of stage 40 skin cultures to T3 resulted in high-level expression of these genes 5 days later, when normal siblings had reached stage 48. This result indicates that T3 induces a stable change in epidermal cells which can be expressed much later, after extensive cell proliferation has occurred in the absence of T3. Once the 63-kDa keratin genes were induced, they were stably expressed, and by the end of metamorphosis T3 had no further effect on their expression. The results suggest that T3 induces constitutive expression of the 63-kDa keratin genes during metamorphosis.

scholarly journals Characterization of Susceptibility and Resistance Responses to Potato Cyst Nematode (Globodera spp.) Infection of Tomato Lines in the Absence and Presence of the Broad-Spectrum Nematode Resistance Hero Gene

2005 ◽  
Vol 18 (2) ◽  
pp. 158-168 ◽  
Author(s):  
Miroslaw Sobczak ◽  
Anna Avrova ◽  
Justyna Jupowicz ◽  
Mark S. Phillips ◽  
Karin Ernst ◽  
...  
Keyword(s):  
Multigene Family ◽  
Expression Profiles ◽  
Transgenic Potato ◽  
Nematode Resistance ◽  
Cyst Nematode ◽  
Potato Cyst Nematode ◽  
Significant Difference ◽  
High Level ◽  
Susceptible Tomato

The tomato Hero A gene is the only member of a multigene family that confers a high level (>80%) of resistance to all the economically important pathotypes of potato cyst nematode (PCN) species Globodera rostochiensis and G. pallida. Although the resistance levels of transgenic tomato lines were similar to those of the tomato line LA1792 containing the introgressed Hero multigene family, transgenic potato plants expressing the tomato Hero A gene are not resistant to PCNs. Comparative microscopy studies of in vitro infected roots of PCN-susceptible tomato cv. Money Maker, the resistant breeding line LA1792, and transgenic line L10 with Ro1 pathotype have revealed no statistically significant difference in the number of juveniles invading roots. However, syncytia (specialized feeding cells) induced in LA1792 and L10 roots mostly were found to have degenerated a few days after their induction, and a few surviving syncytia were able to support only the development of males rather than females. Thus, the ratio between males and females was biased towards males on LA1792 and L10 roots. A series of changes occur in resistant plants leading to formation of a layer of necrotic cells separating the syncytium from stellar conductive tissues and this is followed by degradation of the syncytium. Although the Hero A gene is expressed in all tissues, including roots, stems, leaves, and flower buds, its expression is upregulated in roots in response to PCN infection. Moreover, the expression profiles of the Hero A correlates with the timing of death of the syncytium.

Thyroid hormone induces constitutive keratin gene expression during Xenopus laevis development

1989 ◽  
Vol 9 (5) ◽  
pp. 1823-1831
Author(s):  
P M Mathisen ◽  
L Miller
Keyword(s):  
Thyroid Hormone ◽  
Xenopus Laevis ◽  
Constitutive Expression ◽  
High Level Expression ◽  
Keratin Gene ◽  
Explant Cultures ◽  
Extensive Cell ◽  
High Level

We have used in vitro explant cultures of Xenopus laevis skin to investigate the role that the thyroid hormone triiodothyronine (T3) plays in activating the 63-kilodalton (kDa) keratin genes. The activation of these genes in vivo requires two distinct steps, one independent of T3 and one dependent on T3. In this report we have shown that the same two steps are required to fully activate the 63-kDa keratin genes in skin explant cultures, and we have characterized the T3-mediated step in greater detail. Unlike the induction of transcription by T3 or steroid hormones in adult tissues, there was a long latent period of approximately 2 days between the addition of T3 to skin cultures and an increase in concentration of keratin mRNA. While the T3 induction of 63-kDa keratin gene transcription cannot occur until age 48, a short transient exposure of stage 40 skin cultures to T3 resulted in high-level expression of these genes 5 days later, when normal siblings had reached stage 48. This result indicates that T3 induces a stable change in epidermal cells which can be expressed much later, after extensive cell proliferation has occurred in the absence of T3. Once the 63-kDa keratin genes were induced, they were stably expressed, and by the end of metamorphosis T3 had no further effect on their expression. The results suggest that T3 induces constitutive expression of the 63-kDa keratin genes during metamorphosis.

scholarly journals Preparation and In Vitro Characterization of Chitosan Nanoparticles and Their Broad-Spectrum Antifungal Action Compared to Antibacterial Activities against Phytopathogens of Tomato

Agronomy ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 21 ◽  
Author(s):  
Jae-Wook OH ◽  
Se Chul Chun ◽  
Murugesan Chandrasekaran
Keyword(s):  
Xanthomonas Campestris ◽  
Phytophthora Capsici ◽  
Chitosan Nanoparticles ◽  
Crop Protection ◽  
Erwinia Carotovora ◽  
Maximum Growth ◽  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Phytopathogenic Fungi

The present study was to prepare chitosan nanoparticles (CNPs) from chitosan (CS) to evaluate their in vitro antimicrobial activities against phytopathogens of tomato. We prepared and characterized CNPs for their particle size, polydispersity index, and structures. The antifungal properties of CS and CNPs against phytopathogenic fungi namely Colletotrichum gelosporidies, Phytophthora capsici, Sclerotinia sclerotiorum, Fusarium oxysporum, Gibberella fujikuori were investigated. CNPs showed the maximum growth inhibitory effects on mycelial growth of F. oxysporum followed by P. capsici. We also studied antibacterial activities against phytopathogenic bacteria, such as three strains of Erwinia carotovora subsp. carotovora and one strain of Xanthomonas campestris pv. vesicatoria. Our results showed that both CS and CNPs markedly inhibited the growth of the both Xanthomonas and Erwinia strains. From our study, it is evident that both CS and CNPs have tremendous potential against phytopathogens of tomato for further field screening towards crop protection.

scholarly journals Spi-1/PU.1 transgenic mice develop multistep erythroleukemias.

1996 ◽  
Vol 16 (5) ◽  
pp. 2453-2463 ◽  
Author(s):  
F Moreau-Gachelin ◽  
F Wendling ◽  
T Molina ◽  
N Denis ◽  
M Titeux ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Insertional Mutagenesis ◽  
Constitutive Expression ◽  
Transgenic Animals ◽  
Founder Line ◽  
Mouse Tissues ◽  
High Level

Insertional mutagenesis of the spi-1 gene is associated with the emergence of malignant proerythroblasts during Friend virus-induced acute erythroleukemia. To determine the role of spi-1/PU.1 in the genesis of leukemia, we generated spi-1 transgenic mice. In one founder line the transgene was overexpressed as an unexpected-size transcript in various mouse tissues. Homozygous transgenic animals gave rise to live-born offspring, but 50% of the animals developed a multistep erythroleukemia within 1.5 to 6 months of birth whereas the remainder survived without evidence of disease. At the onset of the disease, mice became severely anemic. Their hematopoietic tissues were massively invaded with nontumorigenic proerythroblasts that express a high level of Spi-1 protein. These transgenic proerythroblasts are partially blocked in differentiation and strictly dependent on erythropoietin for their proliferation both in vivo and in vitro. A complete but transient regression of the disease was observed after erythrocyte transfusion, suggesting that the constitutive expression of spi-1 is related to the block of the differentiation of erythroid precursors. At relapse, erythropoietin-independent malignant proerythroblasts arose. Growth factor autonomy could be partially explained by the autocrine secretion of erythropoietin; however, other genetic events appear to be necessary to confer the full malignant phenotype. These results reveal that overexpression of spi-1 is essential for malignant erythropoiesis and does not alter other hematopoietic lineages.

scholarly journals Identification of Lycopersicon spp. hybrids on the basis of morphological and molecular (RAPD) properties as well as evaluation of resistance to Tomato Spotted Wilt Virus (TSWV)

2014 ◽  
Vol 71 (2) ◽  
pp. 109-114
Author(s):  
Zbigniew Rusinowski ◽  
Mieczysław Śmiech ◽  
Maria Kamińska ◽  
Katarzyna Niemirowicz-Szczytt
Keyword(s):  
Negative Control ◽  
Wild Form ◽  
Transfer Resistance ◽  
Tomato Spotted Wilt ◽  
Enhanced Resistance ◽  
High Level ◽  
Wilt Virus ◽  
Intermediate Traits ◽  
Hybrid Development

The aim of the study was to evaluate the plants obtained as a result of cultivated tomato crosses with wild species meant to transfer resistance to TSWV. Six viable plants were obtained from <em>L. esculentum</em> x <em>L. chilense</em> and <em>L. esculentum</em> x <em>L. peruvianum</em> crosses after the application of in vitro embryo culture. In terms of such morphological traits as growth habit of plants, size and shape of leaves, the length and colour of internodes in branching stems, the plants displayed intermediate traits, resembling, nonetheless, the wild form. RAPD analysis with 8 primers revealed that all the hybrids had bands typical of the paternal forms. This confirms the paternal component in hybrid development. As far as the resistance to Polish TSWV isolates is concerned, two hybrids exhibited a high level of resistance, similar to negative control, three hybrids - enhanced resistance and one hybrid was susceptible to TSWV infection.

scholarly journals Inhibition of Fungal and Bacterial Plant Pathogens by Synthetic Peptides: In Vitro Growth Inhibition, Interaction Between Peptides and Inhibition of Disease Progression

2000 ◽  
Vol 13 (8) ◽  
pp. 847-859 ◽  
Author(s):  
Gul Shad Ali ◽  
A. S. N. Reddy
Keyword(s):  
Growth Inhibition ◽  
Plant Pathogens ◽  
Alternaria Solani ◽  
Hyphal Growth ◽  
Pathogenic Fungi ◽  
Erwinia Carotovora ◽  
Transgenic Potato ◽  
Antimicrobial Activities ◽  
Potato Plants

Four synthetic cationic peptides, pep6, pep7, pep11 and pep20, were tested alone and in combinations for their antimicrobial activities against economically important plant pathogenic fungi (Phytophthora infestans and Alternaria solani) and bacteria (Erwinia carotovora subsp. carotovora and E. carotovora subsp. atroseptica). In in vitro studies, P. infestans and A. solani were inhibited by all four peptides, while E. carotovora subsp. carotovora and E. carotovora subsp. atroseptica were inhibited only by pep11 and pep20. All peptides completely inhibited P. infestans and A. solani on potato leaves and P. infestans on tubers at concentrations comparable to the in vitro IC50 (effective concentration for 50% growth inhibition) values, suggesting that these peptides are more potent in preventing infection than in inhibiting hyphal growth in vitro. Microscopic observations of P. infestans and A. solani when treated with these peptides revealed hyphal anomalies. In tuber-infectivity assays, pep11 and pep20 reduced bacterial softrot symptoms by 50% at 2.0 to 2.30 μM and by 100% at 20 μM. In assays involving two-way combinations of these peptides, growth inhibitions of fungi and bacteria by the combinations were no more than the sum of growth inhibitions by each peptide when used alone, indicating that they act additively. pep11 and pep20 are not phytotoxic to potato plants at 200 μM. With strong and broad-spectrum antimicrobial activities of pep11 and pep20 against fungi and bacteria, and with no antagonistic activities, the expression of these peptides in transgenic potato plants could lead to enhanced disease resistance against these pathogens.

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