Hydrolase Activity in Transgenic Peanut

Chenault, Kelly D.; Burns, J. A.; Melouk, H. A.; Payton, Mark E.

doi:10.3146/pnut.29.2.0003

Cited by 30 publications

(44 citation statements)

References 21 publications

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“…Other studies have suggested that additional factors, such as hydrolytic enzymes, are likely to be important in establishing infection and progression of disease caused by S. minor. Based on the observation that coexpression of glucanase and chitinase genes in transgenic tobacco enhanced protection against fungal attack (Zhu et al, 1994), these genes have also been introduced into peanut (Chenault et al, 2002). Expression of multiple resistance genes may offer a better approach for providing greater and longlasting fungal resistance.…”

Section: Discussionmentioning

confidence: 99%

Enhancing Resistance to Sclerotinia minor in Peanut by Expressing a Barley Oxalate Oxidase Gene

Livingstone

Hampton²,

Phipps³

et al. 2005

Plant Physiology

148

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Sclerotinia minor Jagger is the causal agent of Sclerotinia blight, a highly destructive disease of peanut (Arachis hypogaea). Based on evidence that oxalic acid is involved in the pathogenicity of many Sclerotinia species, our objectives were to recover transgenic peanut plants expressing an oxalic acid-degrading oxalate oxidase and to evaluate them for increased resistance to S. minor. Transformed plants were regenerated from embryogenic cultures of three Virginia peanut cultivars (Wilson, Perry, and NC-7). A colorimetric enzyme assay was used to screen for oxalate oxidase activity in leaf tissue. Candidate plants with a range of expression levels were chosen for further analysis. Integration of the transgene was confirmed by Southern-blot analysis, and gene expression was demonstrated in transformants by northern-blot analysis. A sensitive fluorescent enzyme assay was used to quantify expression levels for comparison to the colorimetric protocol. A detached leaflet assay tested whether transgene expression could limit lesion size resulting from direct application of oxalic acid. Lesion size was significantly reduced in transgenic plants compared to nontransformed controls (65%-89% reduction at high oxalic acid concentrations). A second bioassay examined lesion size after inoculation of leaflets with S. minor mycelia. Lesion size was reduced by 75% to 97% in transformed plants, providing evidence that oxalate oxidase can confer enhanced resistance to Sclerotinia blight in peanut.Sclerotinia blight of peanut, caused by the necrotrophic fungus Sclerotinia minor, is one of the most devastating diseases of peanut (Arachis hypogaea) in Virginia, northeastern North Carolina, Oklahoma, and Texas. The fungicide fluazinam provides some protection (Smith et al., 1992), but its benefit to peanut producers is offset by the expense of the multiple applications necessary to achieve modest control. Yield losses due to Sclerotinia blight can be significant. For example, prior to the availability of fluazinam, losses to Sclerotinia blight averaged 10% in Virginia, with pod loss exceeding 50% in severely affected fields (Porter and Melouk, 1997).Oxalic acid is considered a pathogenicity factor in Sclerotinia sclerotiorum and many other fungal pathogens (Maxwell and Lumsden, 1970;Godoy et al., 1990 (Rao and Tewari, 1987), and S. minor (Hollowell et al., 2001). Direct application of oxalic acid to stem or leaf tissue causes marked tissue injury and wilting, similar to plant responses to fungal infection by S. rolfsii (Bateman and Beer, 1965) and S. sclerotiorum (Noyes and Hancock, 1981). The most compelling evidence for the involvement of oxalic acid in disease initiation was the demonstration that mutant isolates of S. sclerotiorum, deficient in oxalic acid production, were not pathogenic on bean (Phaseolus vulgaris), but revertants became pathogenic once they regained the ability to produce oxalic acid (Godoy et al., 1990). Screening for resistance to oxalic acid has also been studied as an indirect test of physiological resist...

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Section: Discussionmentioning

confidence: 99%

Enhancing Resistance to Sclerotinia minor in Peanut by Expressing a Barley Oxalate Oxidase Gene

Livingstone

Hampton²,

Phipps³

et al. 2005

Plant Physiology

148

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“…All plant lines positive for the hphgene were also positive for the N gene, indicating an expected 100% co-transformation frequency for the covalently linked genes. The use of hygromycin resistance as a selectable marker in peanut transformation studies has been well established (9,22,24,43). Plant lines E-Nll-3 and ENll-7 which were hygromycin-resistant but PCR-negative were considered putative escapes.…”

Section: Resultsmentioning

confidence: 99%

“…Somatic embryos were initiated using seed from the cultivar Okrun following procedures similar to those previously reported (9,32 …”

Section: Methodsmentioning

confidence: 99%

Genetic Transformation of a Runner-Type Peanut with the Nucleocapsid Gene of Tomato Spotted Wilt Virus

Chenault¹,

Payton

2003

Peanut Science

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Peanut (Arachis hypogaea L.) lines containing the nucleocapsid protein (N) gene of tomato spotted wilt virus (TSWV) were generated via microprojectile bombardment of somatic embryos from the cultivar Okrun, a runner-type peanut primarily grown in the southwestern U.S. The gene for hygromycin resistance, hph, was included on the plasmid containing the N gene as a selectable marker. PCR and ELISA results indicated that eight of 10 primary transformant lines were positive for incorporation and expression of the TSWV N transgene. PCR and ELISA analyses of T, progeny indicated that two of the eight transgenic lines demonstrated a 3:1 segregation ratio, indicative of incorporation of a single copy of the TSWV N transgene. Transgene expression levels remained constant through the T1 generation.

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“…This crop is susceptible to many types of pathogens including those caused by fungi. Chenaulr et al [87] reported the development of transgenic peanuts which were introduced two hydrolase genes, a glucanase from alfalfa (Medicago sativa L.), and a chitinase from rice (Oryza sativa L.) into somatic embryos using biolistic. Although the study focused on seedlings characterization (found up to 37% of hydrolase activity in transgenic lines), these authors assume that transgenic lines obtained could be promising due to high transgene expression what would exhibit some level of resistance to a broad range of fungal pathogens.…”

Section: Peanuts (Arachis Hypogaea)mentioning

confidence: 99%

Genetic Improvement of Oilseed Crops Using Modern Biotechnology

Villanueva-Mejía¹,

Álvarez²

2017

Advances in Seed Biology

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In 2009, big challenges facing the agricultural sector in the twenty-first century were presented to the world. Human population growth, increased life expectancy, loss of biodiversity, climate change and accelerated land degradation are the main factors contributing to rethink agriculture system production. In that scenery, modern biotechnology has set a stage for the advancement of agricultural practices and it is clearly an important ally to apply a broad array of technologies and innovative systems where they are most needed, such as enhancing crop productivity, increasing yields, and ultimately ensuring food security. One of the biggest challenges is related to technify production systems, but with no doubt, developing genetic improvement toward getting an efficient and sustainable agriculture, generating new seed qualities (new traits), such as, among others, to upset fatty acids content in oilseed crops have been growing up significantly due to industry interest. In this study, a review about the main advances in genetic improvement of some oilseed crops, starting with omics to understand metabolic routes and to find out key genes in seed oil production, and also, getting in use of modern biotechnology to alter the production of fatty acids, and to face biotic challenges in oilseed crops is presented.

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Hydrolase Activity in Transgenic Peanut

Cited by 30 publications

References 21 publications

Enhancing Resistance to Sclerotinia minor in Peanut by Expressing a Barley Oxalate Oxidase Gene

Enhancing Resistance to Sclerotinia minor in Peanut by Expressing a Barley Oxalate Oxidase Gene

Genetic Transformation of a Runner-Type Peanut with the Nucleocapsid Gene of Tomato Spotted Wilt Virus

Genetic Improvement of Oilseed Crops Using Modern Biotechnology

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