scholarly journals Antifungal Activity in Transgenic Peanut (Arachis hypogaea L.) Conferred by a Nonheme Chloroperoxidase Gene

2009 ◽  
Vol 36 (2) ◽  
pp. 126-132 ◽  
Author(s):  
C. Niu ◽  
Y. Akasaka-Kennedy ◽  
P. Faustinelli ◽  
M. Joshi ◽  
K. Rajasekaran ◽  
...  
Keyword(s):  
Crude Protein ◽  
Growth Inhibitor ◽  
Hyphal Growth ◽  
Aflatoxin Contamination ◽  
35S Promoter ◽  
Camv 35S ◽  
P Gene ◽  
Arachis Hypogaea L ◽  
Selection For

Abstract A nonheme chloroperoxidase gene (cpo-p) from Pseudomonas pyrrocinia, a growth inhibitor of mycotoxin-producing fungi, was introduced into peanut via particle bombardment. The expression of the cpo-p gene is predicted to increase pathogen defense in peanut. Embryogenic peanut tissues were bombarded with gold particles coated with plasmid pRT66 carrying the cpo-p and hygromycin phosphotransferase (hph) genes, under the control of a double CaMV 35S and a single CaMV 35S promoter, respectively. Selection for hygromycin-resistant somatic embryos was performed on a liquid medium containing 10–20 mg/L hygromycin 3–4 days after bombardment. The integration and expression of the cpo-p gene was confirmed by Southern, Northern and Western blot analyses. In vitro bioassay using crude protein extracts from transgenic T0, T1, and T4 plants showed inhibition of Aspergillus flavus hyphal growth, which could translate to a reduction in aflatoxin contamination of peanut seed.

Selection for crude protein content in Phalaris tuberosa L. I. Response to selection and preliminary studies on correlated responses

1969 ◽  
Vol 20 (4) ◽  
pp. 643 ◽  
Author(s):  
RJ Clements
Keyword(s):  
Crude Protein ◽  
Nutritive Value ◽  
Breeding Population ◽  
In Vitro Digestibility ◽  
Seedling Vigour ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Selection For ◽  
Pasture Plant

In a highly variable breeding population of P. tuberosa, marked responses were obtained to three generations of selection for high and low crude protein concentration (percentage nitrogen x 6.25) in whole tillers at heading. Total response was similar in each direction, and realized heritability estimates were h2 = 0.25 and h2 = 0.20 in the high and low directions respectively. The responses were accompanied by positively correlated changes in in vitro digestibility and in characters commonly used as indicators of nutritive value of herbage. However, there were large negatively correlated changes in seedling vigour, relative growth rates, and other morphological and physiological characters. The implications of the results for pasture plant breeding are discussed.

Evaluation of Post-harvest Aflatoxin Production in Peanut Germplasm with Resistance to Seed Colonization and Pre-harvest Aflatoxin Contamination

2004 ◽  
Vol 31 (2) ◽  
pp. 124-134 ◽  
Author(s):  
H. Q. Xue ◽  
T. G. Isleib ◽  
G. A. Payne ◽  
G. OBrian
Keyword(s):  
Genotypic Variation ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Block Designs ◽  
Plastic Bags ◽  
Arachis Hypogaea L ◽  
Seed Colonization ◽  
Highly Correlated

Abstract Contamination of peanut (Arachis hypogaea L.) with aflatoxin produced by species of Aspergillus remains a problem for the U.S. peanut industry. Several peanut genotypes were reported to be resistant to in vitro seed colonization by Aspergillus flavus Link ex Fries (IVSCAF), to field seed colonization by A. flavus (FSCAF), or to preharvest aflatoxin contamination (PAC), but few to production of aflatoxin per se. Cotyledons of 39 peanut genotypes reportedly resistant to IVSCAF, FSCAF, or PAC, and eight susceptible to PAC were evaluated in four tests for their ability to support aflatoxin production after inoculation with A. flavus. Cultivars Perry and Gregory were used as checks in each test. Seed cotyledons were separated, manually blanched, inoculated with conidia of A. flavus, placed on moistened filter paper in petri dishes, and incubated for 8 d at 28 C. Dishes were arranged on plastic trays enclosed in plastic bags and stacked with PVC spacers between trays. Incomplete block designs were used for all tests. In each test, none of the genotypes examined was completely resistant to aflatoxin production, but significant genotypic variation was observed in the amount of total aflatoxin accumulated in seeds. Genotypes previously reported to be resistant to IVSCAF, FSCAF, or PAC exhibited differential abilities to support aflatoxin production. PI 590325, PI 590299, PI 290626, and PI 337409 supported reduced levels of aflatoxin, and their degree of resistance was consistent across tests. Fungal growth was highly correlated with aflatoxin production in three tests. The results from this study suggested that there were no absolute relationships of aflatoxin production resistance with IVSCAF, FSCAF, or PAC resistance, but that it should be possible to identify a genotype with high IVSCAF, FSCAF, or PAC resistance and reduced capacity for aflatoxin production by A. flavus.

scholarly journals Interrelationship between stilbene producing ability and Aspergillus colonization on selected peanut (Arachis hypogaea L.) genotypes

2019 ◽  
Vol 46 (2) ◽  
pp. 118-126 ◽  
Author(s):  
Jwalit J Nayak ◽  
Pranavkumar D Gajjar ◽  
Sheikh M Basha ◽  
KSS Naik
Keyword(s):  
Comparative Evaluation ◽  
Breeding Population ◽  
Aflatoxin Contamination ◽  
Fungal Colonization ◽  
Biotic And Abiotic Stresses ◽  
Control Seed ◽  
Arachis Hypogaea L ◽  
Water Cutting ◽  
The Relationship

ABSTRACT Stilbenes are phytoalexins expressed by plants to avoid/resist certain biotic and abiotic stresses. This study was envisioned to determine the interrelationship between stilbenes producing ability of peanut genotypes and Aspergillus colonization level. Stilbenes were induced in peanut cotyledon in vitro by soaking in water, cutting them into thin slices, and subsequently challenging them with Aspergillus flavus. Fungal colonization was then measured in the cotyledon slices. The results showed major differences in fungal colonization levels between the control (seed without stilbene induction) and stilbenes-induced seeds. This finding was further validated using twenty peanut genotypes to ensure the relationship between stilbenes producing ability of the seed and fungal colonization level. The result showed that of the 20 genotypes tested, seeds of genotypes K1504, K1620 and K1632 showed minimal fungal colonization compared to control seed (without stilbenes induction), while genotypes DRT40, Kadiri-7, Narayani, DRT43 and Tirupati-3 showed no fungal colonization. The differences in stilbenes content and composition of cotyledon slices was determined by HPLC to assess genetic differences in their stilbenes producing ability. Comparative evaluation of these data showed that the genotypes that showed no fungal colonization expressed significantly higher amounts of stilbenes compared to genotypes which expressed relatively lower amounts of stilbenes. Overall, these data suggest that the genotypes expressing high amounts of stilbenes were able to mitigate fungal colonization while the genotypes expressing relatively lower amounts of stilbenes sustained fungal colonization, which indicates that this technique may be useful for screening breeding population to identify genotypes capable of avoiding Aspergillus colonization and aflatoxin contamination.

Research note: The 35S promoter is not constitutively expressed in the transgenic tropical actinorhizal tree Casuarina glauca

2002 ◽  
Vol 29 (5) ◽  
pp. 649 ◽  
Author(s):  
Aziz Smouni ◽  
Laurent Laplaze ◽  
Didier Bogusz ◽  
Fathia Guermache ◽  
Florence Auguy ◽  
...  
Keyword(s):  
Vascular Tissue ◽  
Gus Expression ◽  
Cauliflower Mosaic Virus ◽  
Camv 35S Promoter ◽  
35S Promoter ◽  
Casuarina Glauca ◽  
Camv 35S ◽  
Highly Active ◽  
One Year

The tropical nitrogen-fixing tree, Casuarina glauca Sieb. ex Spreng. was genetically transformed using Agrobacterium tumefaciens C58C1(pGV2260; pBIN19GUSINT). We report on the expression pattern conferred by the cauliflower mosaic virus (CaMV) 35S promoter in transgenic C. glauca plants grown in vitro, and for one year in a greenhouse. Histochemical assays in shoots from in vitro plants revealed β-glucuronidase (GUS) staining in apical and axillary buds, and in nearly all tissues near the base of the stem. In roots, the CaMV 35S drove strong GUS expression in the apex and vascular tissue. In 1-year old plants grown in a greenhouse, the CaMV 35S promoter was highly active, except in peripheral suberized tissues. Transgenic C. glauca plants were nodulated by the actinomycete Frankia. Histochemical assays on vibratome sections of transgenic nodules demonstrated intense GUS activity in the vascular bundle, the phellogen, and in strands of uninfected cells filled with polyphenols. GUS expression was undetectable in Frankia-infected cells.

scholarly journals Pseudomonas fluorescens Pf7: A Potential Biocontrol Agent against Aspergillus flavus Induced Aflatoxin Contamination in Groundnut

2019 ◽  
pp. 1-7 ◽  
Author(s):  
M. Ravi Teja ◽  
K. Vijay Krishna Kumar ◽  
H. Sudini
Keyword(s):  
Plant Growth ◽  
Aspergillus Flavus ◽  
Plant Growth Promoting Rhizobacteria ◽  
Aflatoxin Contamination ◽  
Dual Culture ◽  
Arachis Hypogaea L ◽  
Potential Biocontrol Agent ◽  
Plant Growth Promoting ◽  
Growth Promoting

Aflatoxin contamination is a qualitative problem in groundnut (Arachis hypogaea L.) occurring at both pre-and post-harvest stages. These aflatoxins are secondary metabolites produced by Aspergillus flavus and A. parasiticus and have carcinogenic, hepatotoxic, teratogenic and immuno-suppressive effects. Use of plant growth-promoting rhizobacteria (PGPR) is a viable and sustainable option in managing aflatoxin problem in groundnut. Our present study is aimed at identifying a plant growth-promoting rhizobacteria (PGPR) strain with superior antagonistic abilities on A. flavus infection, aflatoxin contamination and to determine its mode of action. Ten native P. fluorescens isolates were isolated from groundnut rhizosphere and screened against A. flavus by dual culture and in vitro seed colonization (IVSC) assays. In dual culture and IVSC studies, Pf7 exhibited higher degree of antagonism on A. flavus (54% inhibition), inhibited its colonization and reduced aflatoxin contamination (27.8 µg kg-1) in kernels.

scholarly journals Biolistic-mediated Transformation of Lilium longiflorum cv. Nellie White

HortScience ◽  
2008 ◽  
Vol 43 (6) ◽  
pp. 1864-1869 ◽  
Author(s):  
Kathryn Kamo ◽  
Bong Hee Han
Keyword(s):  
Transgenic Plants ◽  
Genomic Dna ◽  
Fusion Gene ◽  
Lilium Longiflorum ◽  
Camv 35S Promoter ◽  
35S Promoter ◽  
Ms Medium ◽  
Camv 35S ◽  
Npt Ii

Slow-growing compact calluses were initiated from bulb scales of Lilium longiflorum cv. Nellie White that had been cultured for at least 6 months on Murashige and Skoog (MS) medium with 9 μm dicamba. To develop a reliable selection system, the sensitivity of nontransformed calluses and in vitro plants to different selective agents such as phosphinothricin, kanamycin, geneticin, paromomycin, and hygromycin was tested when grown on MS medium. Nontransformed calluses showed high sensitivity to 0.5 mg·L−1 phosphinothricin, 25 mg·L−1 geneticin, and 5 mg·L−1 hygromycin. Nontransformed plants grown in vitro died on either 2 mg·L−1 phosphinothricin or 75 mg·L−1 hygromycin. Plants did not die when grown on either 200 mg·L−1 kanamycin or 100 mg·L−1 geneticin, and 100 mg·L−1 paromomycin stimulated plant growth. Transformation was achieved using biolistics on callus bombarded with either the bar-uidA fusion gene under control of the CaMV 35S promoter or npt II and uidA under control of the CaMV 35S promoter. One week after biolistic bombardment, callus bombarded with the bar-uidA fusion gene was cultured for 1 month on MS medium supplemented with 9 μm dicamba and 0.1 mg·L−1 phosphinothricin and then transferred to 0.2 mg·L−1 phosphinothricin for 1 month followed by 1.0 mg·L−1 for the next 4 months. Regenerating shoots and well-established plants were cultured on MS medium lacking hormones and with either 0.2 mg·L−1 or 2.0 mg·L−1 phosphinothricin, respectively. Callus bombarded with the npt II gene was cultured on MS medium with 50 mg·L−1 geneticin until shoots regenerated. Regenerated shoots were cultured on MS medium lacking hormones. Under optimal conditions, 10 transgenic plants were selected from seven plates of callus bombarded with the bar-uidA fusion gene using phosphinothricin for selection. Both Southern hybridization of genomic DNA and polymerase chain reaction analysis verified the presence of the transgene in transformed ‘Nellie White’ plants. Transgenic plants were phenotypically normal, and they were crossed with nontransformed plants of L. longiflorum cvs. Sakai, Yin tung, Sakai, and Flavo. The presence of the bar gene in 41% of the T1 progeny plants confirmed stable integration of the transgene into the genomic DNA of transgenic lily plants. β-glucuronidase expression resulting from the uidA gene was demonstrated in leaves and roots of some of the transgenic lily plants by histochemical staining, determination of the specific activity of the β-glucuronidase enzyme, and Northern hybridization.

Transgenic cotton (Gossypium hirsutum) over-expressing alcohol dehydrogenase shows increased ethanol fermentation but no increase in tolerance to oxygen deficiency

2000 ◽  
Vol 27 (11) ◽  
pp. 1041 ◽  
Author(s):  
Marc H. Ellis ◽  
Anthony A. Millar ◽  
Danny J. Llewellyn ◽  
W. James Peacock ◽  
Elizabeth S. Dennis
Keyword(s):  
Alcohol Dehydrogenase ◽  
Ethanol Fermentation ◽  
Camv 35S Promoter ◽  
35S Promoter ◽  
Mild Stress ◽  
Waterlogging Tolerance ◽  
Over Expression ◽  
Camv 35S ◽  
Adh Activity

Cotton (Gossypium hirsutumL.) was transformed with constructs for the over-expression of two enzymes involved in ethanol fermentation, alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC), with the goal of increasing waterlogging tolerance. Four independent transgenic lines transformed with the cotton Adh2 cDNA driven by the CaMV 35S promoter showed ectopic expression of this isozyme in leaves and up to 20-fold greater in vitro ADH activity in roots. Under conditions of O2 deficiency, excised roots from these transgenic plants showed up to 80% increase in ethanol evolution compared to untransformed roots. Conversely, one line transformed with a construct containing the Adh2 coding region in the antisense orientation showed a 65% decrease in ADH activity and a 25% decrease in ethanol production from anaerobic roots relative to untransformed cotton. Lines transformed with a rice Pdc1 cDNA driven by the CaMV 35S promoter showed high levels of expression of the transgene-encoded protein in leaves, but only very low levels of protein and no in vitro enzyme activity detectable in the roots of these plants. Roots from plants transformed with the 35S-Pdc construct did not produce more ethanol than roots from untransformed controls. We tested the ability of cotton roots to withstand low O2 treatments under hydroponic conditions. Neither the ‘ADH’ nor the ‘PDC’ transgenics showed more tolerance than the wild-type on the basis of root growth under a mild stress (5% O2), a strong stress (0% O2 with or without a 5% O2 pretreatment), or in recovery growth following these treatments. Our results show that over-expression of ADH can lead to ethanol over-production (even though the activity of this enzyme by far exceeds that of PDC, its precursor in the pathway), but this is not sufficient to increase waterlogging tolerance in cotton.

Dry matter intake and nutrient selection by lactating cows grazing irrigated pastures at different pasture allowances in summer and autumn

1998 ◽  
Vol 38 (5) ◽  
pp. 451 ◽  
Author(s):  
W. J. Wales ◽  
P. T. Doyle ◽  
D. W. Dellow
Keyword(s):  
Milk Production ◽  
Perennial Ryegrass ◽  
Crude Protein ◽  
Dry Matter ◽  
Fibre Content ◽  
Lactating Cows ◽  
Dry Matter Digestibility ◽  
Herbage Intake ◽  
Selection For

Summary. Three experiments investigating the effects of herbage allowance on the consumption of nutrients by lactating cows were conducted on irrigated perennial pastures in northern Victoria during summer and autumn. Experiment 1 was conducted in mid lactation (autumn–early winter) with perennial ryegrass [54% of dry matter (DM)]–white clover (22% of DM) pasture offered at allowances of 15, 20, 30 and 40 kg DM/cow.day. Herbage intake increased (P<0.001) from 8.0 to 14.6 kg DM/cow.day as allowance increased and this was associated with a decrease (P<0.001) in utilisation from 54 to 37%. The cows consistently selected a diet 11% higher in in vitro dry matter digestibility than that in the pasture on offer, but selection for crude protein increased (P<0.001) from 21 to 41% above that in herbage on offer as herbage allowance increased. Neutral detergent fibre content of the diet selected was lower (P<0.001) than that in herbage on offer. Along with these changes, milk production increased (P<0.001) from 9.0 to 15.5 kg/day as herbage allowance increased at a marginal response of 0.99 kg milk/kg extra DM consumed. Experiments 2 and 3 were conducted in mid lactation (summer) on pasture containing 28% paspalum, 26% weeds, 17% perennial ryegrass or 36% paspalum, 19% weeds and 24% ryegrass respectively. Pasture allowances were between 20 and 70 kg DM/cow.day. Herbage intake increased (P<0.001) from about 8 to 17 kg DM/cow.day as allowance increased in both experiments and was accompanied by a decrease (P<0.001) in utilisation from about 40 to less than 25%. In experiment 2, the cows consistently selected a diet with a similar in vitro dry matter digestibility to that of the herbage pregrazing, regardless of allowance, but selection for crude protein increased (P<0.05) from 25 to 45% above that in herbage on offer, as allowance increased. In experiment 3, the diet selected was 13% greater (P<0.001) in in vitro dry matter digestibility and 42% greater (P<0.001) in crude protein than the herbage on offer. Neutral detergent fibre content of the diet selected was lower (P<0.001) than that in herbage on offer in experiment 3, while the difference was small in experiment 2. Along with these changes, milk production increased (P<0.001) (in experiment 2, 12.3–15.0 kg/cow.day; experiment 3, 10.0–15.8 kg/cow.day) as herbage allowance increased, but the marginal responses were lower (0.28 kg milk/kg extra DM consumed in experiment 2, 0.64 kg milk/kg extra DM consumed in experiment 3) than observed in experiment 1 reflecting the differences in pasture quality.

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