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Robert F. Cressman

Bio: Robert F. Cressman is an academic researcher from DuPont. The author has contributed to research in topics: Recombinant DNA & Phosphorylation. The author has an hindex of 7, co-authored 14 publications receiving 1826 citations.

Papers
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Journal ArticleDOI
22 Nov 1991-Science
TL;DR: Transgenic tobacco seedlings constitutively expressing a bean chitinase gene under control of the cauliflower mosaic virus 35S promoter showed an increased ability to survive in soil infested with the fungal pathogen Rhizoctonia solani and delayed development of disease symptoms.
Abstract: The production of enzymes capable of degrading the cell walls of invading phytopathogenic fungi is an important component of the defense response of plants. The timing of this natural host defense mechanism was modified to produce fungal-resistant plants. Transgenic tobacco seedlings constitutively expressing a bean chitinase gene under control of the cauliflower mosaic virus 35S promoter showed an increased ability to survive in soil infested with the fungal pathogen Rhizoctonia solani and delayed development of disease symptoms.

1,025 citations

Journal ArticleDOI
TL;DR: Ethylene-dependent expression of a chimeric gene consisting of 1.6 kilobases of 5'-flanking DNA derived from the CH5B gene fused to the coding sequence of beta-glucuronidase indicates that this region of the CH 5B gene is sufficient for ethylene-regulated expression.
Abstract: Expression of at least two genes from bean encoding the defense-related protein chitinase has been shown previously to be transcriptionally regulated by the phytohormone ethylene. We have determined the complete nucleotide sequence of one of these genes, the CH5B gene, which resides on a 4.7-kilobase fragment of bean genomic DNA. The structural gene consists of a single open reading frame and encodes the 301 amino acids of the mature protein and a 26-amino acid signal peptide. The CH5B gene has been introduced into tobacco plants using Agrobacterium Ti-plasmid vectors. Little or no expression of the bean gene was observed when transgenic tobacco plants were grown in air; however, exposure of these plants to an atmosphere containing 50 parts per million ethylene resulted in an approximately 20-fold to 50-fold increase in the level of the bean chitinase mRNA. Ethylene-dependent expression of a chimeric gene consisting of 1.6 kilobases of 59-flanking DNA derived from the CH5B gene fused to the coding sequence of beta-glucuronidase indicates that this region of the CH5B gene is sufficient for ethylene-regulated expression. Deletion analysis of the CH5B promoter region has allowed us to localize these DNA sequences to within a 228-base pair region situated between -422 and -195 upstream of the transcriptional start site. This region is characterized by two short DNA sequences that are exactly conserved in a second ethylene-regulated bean chitinase gene.

185 citations

Patent
29 Apr 2004
TL;DR: In this paper, the authors provide DNA compositions that relate to transgenic insect resistant maize plants and assays for detecting the presence of the maize TC1507 event based on the DNA sequence of the recombinant construct inserted into the maize genome and the DNA sequences flanking the insertion site.
Abstract: The invention provides DNA compositions that relate to transgenic insect resistant maize plants. Also provided are assays for detecting the presence of the maize TC1507 event based on the DNA sequence of the recombinant construct inserted into the maize genome and the DNA sequences flanking the insertion site. Kits and conditions useful in conducting the assays are provided.

172 citations

Patent
25 Jun 2007
TL;DR: In this article, a method for identifying and detecting high oleic acid/ALS inhibitor-tolerant soybean plants is proposed. But the method requires the identification of the insertion sites of the transgene insertion sites.
Abstract: Compositions and methods related to transgenic high oleic acid/ALS inhibitor-tolerant soybean plants are provided. Specifically, the present invention provides soybean plants having a DP-305423-1 event which imparts a high oleic acid phenotype and tolerance to at least one ALS-inhibiting herbicide. The soybean plant harboring the DP-305423-1 event comprises genomic/transgene junctions having at least the polynucleotide sequence of SEQ ID NO:8, 9, 14, 15, 20, 21, 83 or 84. The characterization of the genomic insertion site of the DP-305423-1 event provides for an enhanced breeding efficiency and enables the use of molecular markers to track the transgene insert in the breeding populations and progeny thereof. Various methods and compositions for the identification, detection, and use of the soybean DP-305423-1 events are provided.

162 citations

Patent
26 Jun 2003
TL;DR: In this article, an isolated nucleic acid fragment encoding a starch R1 phosphorylation protein was used to construct a chimeric gene encoding all or a portion of the protein, in sense or antisense orientation.
Abstract: This invention relates to an isolated nucleic acid fragment encoding a starch R1 phosphorylation protein. The invention also relates to the construction of a chimeric gene encoding all or a portion of the starch R1 phosphorylation protein, in sense or antisense orientation, wherein expression of the chimeric gene results in production of altered levels of the starch R1 phosphorylation protein in a transformed host cell.

154 citations


Cited by
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Journal ArticleDOI
TL;DR: The essential prerequisites for pathogen recognition and the induction of localized defense responses are examined, showing which responses are required to abolish or retard pathogen growth and how.
Abstract: Plants are constantly being challenged by aspiring pathogens, but disease is rare. Why? Broadly, there are three reasons for pathogen failure. Either (1) the plant is unable to support the niche requirements of a potential pathogen and is thus a non? host; or (2) the plant possesses preformed structural barriers or toxic compounds that confine successful infections to specialized pathogen species; or (3) upon recognition of the attacking pathogen, defense mechanisms are elaborated and the invasion remains localized. All three types of interaction are said to be incompatible, but only the latter resistance mech? anism depends on induced responses. Successful pathogen invasion and disease (compatibility) ensue if the preformed plant defenses are inappropriate, the plant does not detect the pathogen, or the activated defense responses are ineffective. In this review, we examine the essential prerequisites for patho? gen recognition and the induction of localized defense responses. Preformed defenses are considered elsewhere in this issue (see Osbourn, 1996, in this issue). Race-specific pathogen recognition is hypothesized to re? sult from the direct or indirect interaction of the product of a dominant or semidominant plant resistance (R) gene with a product derived from the corresponding dominant pathogen avirulence (Avr) gene (Keen, 1992; Staskawicz et al., 1995). Subsequent signal transduction events are assumed to coordinate the activation of an array of defense responses. This "simple" model appears to explain much but begs many questions. For example, R gene products are likely to provide key components for recognition, but how do the distinct classes of R proteins characterized to date (see Bent, 1996, in this is? sue) activate the defense response? Do different R gene classes activate distinct responses? The regulation of some components of defense mechanisms has been studied in plant cell cultures in response to non-race-specific elicitors, but to what extent do such studies provide a model for R gene func? tion? Plant resistance is often correlated with the activation of specific defense responses, but which (if any) are required to abolish or retard pathogen growth, and how? Which are pri? mary responses and which are secondary? Does the first response involve transcriptional regulation, the activation of preformed enzymes, and/or the opening of ion channels, or

1,772 citations

Journal ArticleDOI
18 Nov 1994-Science
TL;DR: Transgenic tobacco and Arabidopsis thaliana expressing the bacterial enzyme salicylate hydroxylase cannot accumulate salicylic acid, which makes the plants unable to induce systemic acquired resistance, but also leads to increased susceptibility to viral, fungal, and bacterial pathogens.
Abstract: Transgenic tobacco and Arabidopsis thaliana expressing the bacterial enzyme salicylate hydroxylase cannot accumulate salicylic acid (SA). This defect not only makes the plants unable to induce systemic acquired resistance, but also leads to increased susceptibility to viral, fungal, and bacterial pathogens. The enhanced susceptibility extends even to host-pathogen combinations that would normally result in genetic resistance. Therefore, SA accumulation is essential for expression of multiple modes of plant disease resistance.

1,662 citations

Journal ArticleDOI
TL;DR: A role for PR genes in preventing the proximal spread of pathogens in addition to their suggested role in SAR is suggested after the insensitivity of npr1 to SA, INA, and avirulent pathogens in SAR induction indicates that these inducers share a common signal transduction pathway.
Abstract: Systemic acquired resistance (SAR) is a general defense response in plants that is characterized by the expression of pathogenesis-related (PR) genes. SAR can be induced after a hypersensitive response to an avirulent pathogen or by treatment with either salicylic acid (SA) or 2,6-dichloroisonicotinic acid (INA). To dissect the signal transduction pathway of SAR, we isolated an Arabidopsis mutant that lacks the expression of an SA-, INA-, and pathogen-responsive chimeric reporter gene composed of the 5[prime] untranslated region of an Arabidopsis PR gene, [beta]-1,3-glucanase (BGL2), and the coding region of [beta]-glucuronidase (GUS). This mutant, npr1 (nonexpresser of PR genes), carries a single recessive mutation that abolishes the SAR-responsive expression of other PR genes as well. While SA-, INA-, or avirulent pathogen-induced SAR protects wild-type plants from Pseudomonas syringae infection, the mutant cannot be protected by pretreatment with these inducers. The insensitivity of npr1 to SA, INA, and avirulent pathogens in SAR induction indicates that these inducers share a common signal transduction pathway. Moreover, in npr1, the localized expression of PR genes induced by a virulent Pseudomonas pathogen is disrupted, and the lesion formed is less confined. These results suggest a role for PR genes in preventing the proximal spread of pathogens in addition to their suggested role in SAR.

1,421 citations

Journal ArticleDOI
TL;DR: Alterations in the response of dark-grown seedlings to ethylene (the "triple response") were used to isolate a collection of ethylene-related mutants in Arabidopsis thaliana and should prove to be useful tools for dissecting the mode of Ethylene action in plants.
Abstract: Alterations in the response of dark-grown seedlings to ethylene (the "triple response") were used to isolate a collection of ethylene-related mutants in Arabidopsis thaliana. Mutants displaying a constitutive response (eto1) were found to produce at least 40 times more ethylene than the wild type. The morphological defects in etiolated eto1-1 seedlings reverted to wild type under conditions in which ethylene biosynthesis or ethylene action were inhibited. Mutants that failed to display the apical hook in the absence of ethylene (his1) exhibited reduced ethylene production. In the presence of exogenous ethylene, hypocotyl and root of etiolated his1-1 seedlings were inhibited in elongation but no apical hook was observed. Mutants that were insensitive to ethylene (ein1 and ein2) produced increased amounts of ethylene, displayed hormone insensitivity in both hypocotyl and root responses, and showed an apical hook. Each of the "triple response" mutants has an effect on the shape of the seedling and on the production of the hormone. These mutants should prove to be useful tools for dissecting the mode of ethylene action in plants.

1,284 citations

Journal ArticleDOI
TL;DR: The molecular events underlying SAR are discussed: the mechanisms involved in SAR, including lignification and other structural barriers, pathogenesis-related proteins and their expression, and the signals for SAR including salicylic acid.
Abstract: This paper examines induced resistance (SAR) in plants against various insect and pathogenic invaders. SAR confers quantitative protection against a broad spectrum of microorganisms in a manner comparable to immunization in mammals, although the underlying mechanisms differ. Discussed here are the molecular events underlying SAR: the mechanisms involved in SAR, including lignification and other structural barriers, pathogenesis-related proteins and their expression, and the signals for SAR including salicylic acid. Recent findings on the biological role of systemin, ethylene, jasmonates, and electrical signals are reviewed. Chemical activators of SAR comprise inorganic compounds, natural compounds, and synthetic compounds. Plants known to exhibit SAR and induced systemic resistance are listed.

1,270 citations