Genetic Analysis and Molecular Identification of Virulence in Xanthomonas oryzaepv.oryzaeIsolates

Bacterial leaf blight (BLB) of rice is a very destructive disease worldwide and is caused byXanthomonas oryzaepv.oryzae(Xoo).The aimofthepresentstudywastoexamineiftheXoovirulence pathotypes obtained using phenotypic pathotyping could be confirmed using molecular approach. After screening of 60 Operon primers with genomic DNA of twoXooisolates (virulent pathotype,Vr, and mildly virulent pathotype,MVr), 12 Operon primers that gave reproducible and useful genetic information were selected and used to analyze 50Xooisolates from 7 West African countries. Genetic analysis revealed two majorXoovirulence genotypes (Mta andMtb)withMtahaving two subgroups (Mta1andMta2).Mta1(Vr1) subgroup genotype has occurrence in six countries and Mta2(Vr2) in three countries whileMtbgenotype characterized mildly virulence (MVr)Xooisolates present in five countries. The study revealed possible linkage and correlation between phenotypic pathotyping and molecular typing ofXoovirulence.Xoo virulence genotypes were known to exist within country and there was evidence ofXoopathogen migration between countries. Durable resistance rice cultivars would need to overcome bothMtaandMtb Xoovirulence genotypes in order to survive after their deployment into different rice ecologies in West Africa

Two genotypes of Xanthomonas oryzae pv. oryzae virulence identified in West Africa

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo), is a very destructive rice disease worldwide. The aim of the present study was to examine if the Xoo virulence pathotypes obtained using phenotypic pathotyping could be confirmed using molecular approach. After screening of 60 Operon primers with genomic DNA of two Xoo isolates (virulent pathotype, Vr and mildly virulent pathotype, MVr), 12 Operon primers that gave reproducible and useful genetic information were selected and used to analyze 50 Xoo isolates from 7 West African countries. Genetic analysis revealed two major Xoo virulence molecular type (Mt) which were Mta and Mtb with Mta having two subgroups (Mta1 and Mta2). Mta1 (Vr1) subgroup genotype has occurrence in six countries and Mta2 (Vr2) in three countries while Mtb genotype characterized mildly virulence (MVr) Xoo isolates present in five countries. The study revealed possible linkage and correlation between phenotypic pathotyping and molecular typing of Xoo virulence. Durable resistance rice cultivars would need to overcome both Mta and Mtb Xoo virulence genotypes in order to survive after their deployment into different rice ecologies in West Africa

Evaluation and potential of Double Immunodifusion Gel Assay for serological characterization of rice yellow mottle virus isolates in West Africa

Rice yellow mottle virus is not only highly infectious to rice plants but also a highly variable pathogen. Forty-two isolates were obtained from five countries in West Africa. Utilizing 26 polyclonal antisera, the serological diversity of these isolates was determined using Double Immunodifusion Gel Assay. All the antisera were classified into three serogroups, PSg-1a, PSg-1b and PSg-2. Antisera belonging to PSg- 1a, PSg-1b and PSg-2 serogroups had diagnostic potential of 86-90%, 69-76% and 52-64%, respectively, for the 42 RYMV isolates analyzed using a dilution of up 1:200. Moreover, all isolates were separated into three serogroups, Sg-1a, Sg-1b and Sg-2. The first two groups are widely distributed across West Africa. The high diagnostic potential exhibited by the 26 RYMV polyclonal antisera indicates that Double Immunodifusion Gel Assay is useful and reliable for diagnosing RYMV. As the use of ELISA (Enzyme-Linked Immunosorbent Assay) is expensive and unavailable in most of the national agricultural research institute in West Africa, they can adopt Double Immunodifusion Gel Assay for the identification and characterization of Rice yellow mottle virus isolates. This is the first phylogenetic analysis report on the use of Double Immunodifusion Gel Assay to characterize Rice yellow mottle virus isolates in West Africa

Ameliorative Effect of Zingiber officinale on Chemical Induced DNA Damage in Rats Using PCR Analysis

Ginger rhizomes have been reportedly used in folk medicine for the management of various ailments. This study, therefore, investigates the ameliorative effect of the ethanolic extract of ginger (Zingiber officinale) rhizomes against DNA damage in rats induced with different carcinogens. Fifteen Wistar rats grouped into 3 of 5 rats per group were used for the study. The first set of blood samples was first collected before the animals were orally treated with heavy metals. After 14 days of induction, the second set of blood was collected. The third phase of blood collection was done after administering an ethanolic extract of Z. officinale for 14 days. The UV wavelength absorption spectrum and conventional PCR analysis were carried out on DNA extracts of all the animals. Cluster analysis of optical density (OD) and PCR data were carried out as well as genomic instability, similarity, and diversity using the best 3 Random Amplified Polymorphic DNA (RAPD) primers. The PCR –DNA concentration analysis showed the Z. officinale extract's ameliorative effect against lead acetate, cadmium chloride, and arsenic trioxide-induced DNA damage with a significant (p < 0.05) reduction in DNA concentration of the treated rats when compared with induced rats. The cluster analysis of optical density values revealed close similarity between the control animals' DNA, a slight similarity with treated animals' DNA, and a significant difference with the induced animal DNA. These results indicated the ameliorative properties of Z. officinale against these heavy metals induced DNA damage in rats

PROTECTIVE EFFECT OF ETHANOLIC EXTRACT OF CRASSOCEPHALUM RUBENSLEAVES ON CARBON TETRACHLORIDE -INDUCED LIVER DAMAGE IN RATS

Natural products, most especially from plant origin, possess antioxidant propertieswhich are known toplaycrucial roles in preventing and treating various pathological conditions occasioned by free radicals. Crassocephalum rubens is aone of those plants, and this study investigated the protective properties of ethanolic extract of C.rubens(EECR) leaves against hepatic damageinduced by carbon tetrachloride (CCl4). Thirty rats divided into 6 groups (n=5) were used for the investigation. Group 1 served as normal control while groups 2, 3 and 4 were pretreated for 21 days with EECR leaves at 150 mg/kg, 300 mg/kg and 450 mg/kg b.w.respectively, prior to a single intraperitoneal administration of CCl4. Animals in groups 5 received only the extract at a dose of 450 mg/kg body weight whileanimals in group 6 were given only CCl4. All animals were sacrificed 24 hafter the administration of CCl4. CCl4significantly (p < 0.05) induced marked hepatic damage as revealed by increased activities of plasma ALT, AST, GGT and ALP. Also, plasma total protein and albumin were significantly decreased in CCl4-treated animals relativeto normal control. Analyses of antioxidant statusshowed that CCl4elicited a significant decrease in the activities of antioxidant enzymes, with an increase in malondialdehyde levelsin liver. Pre-treatment with the EECR leavesat all doses testedhowever,significantly (p<0.05) reduced the observed biochemical lesions. The hepatoprotective effect of the EECR may be traceable to the presence of phytochemicals inherent in the plant

Hepatoprotective Effect of Aqueous Extract of Solanum macrocarponLeavesagainst Carbon tetrachloride-Induced Liver Damage in Rats

Liver damage is a growing concern of today’s modern society. The increasing incidence of exposure to toxic agents has contributed to liver diseases. There is therefore need for hepatoprotective agents. This study was aimed at investigating the protective effect of aqueous extract of the leaves of Solanum macrocarponagainst CCl4-induced liver damage in rats. Six groups of four animals each were used for the investigation. Group 1 served as control, groups 2, 3 and 4 animals were pre-treated with leaf extract of Solanum macrocarponat 250mg/kg, 500mg/kg and 750mg/kg body weight respectively for 14 days prior to a single intraperitoneal administration of CCl4. Animals in groups 5 and 6 received only the extract at a dose of 750mg/kg body weight and CCl4respectively. All animals were sacrificed 24 h after the administration of CCl4.The liver functions tests were performed in addition to their histopathological evaluation.Results obtained showed significant adverse changes in the levels of all measured parameters in CCl4treated rats. However, pre-treatment with aqueous extract of S. macrocarponprevented the adverse changes. Our findings suggest that S. macrocarponprotects the liver against CCl4-induced damage. This could be attributed to the presence of phytochemical compounds in the plant

High Performance Liquid Chromatography (HPLC) Fingerprinting, Mineral Composition and In Vitro Antioxidant Activity of Methanol Leaf Extract of Synsepalum dulcificum (Sapotaceae)

This study was carried out to identify the phytochemicals and in vitro antioxidant activity of methanol leaf extract of Synsepalum dulcificum (MSD). Standard protocols were used to evaluate the total phenols, total flavonoids and total antioxidants content of the extract. Nitric oxide (NO), hydroxyl radical (OH), ABTS ·+ and 2 ,2 - diphenyl - 1 - picrylhydrazyl (DPPH) radicals scavenging activity, inhibition of lipid peroxidation and the ability of MSD to chelate ferrous ion as well its reductive potential were also evaluated. High Performance Liquid Chromatography ( HPLC) was used to confirm the presence of polyphenols and carotenoids. Results showed the presence of flavonoids, saponins, terpenoids and cardiac glycosides in the extract. Among others, appreciable levels of potassium, calcium, sodium and magnesium were detected in the e xtract. The IC 50 of the extract for DPPH, NO, OH - , and ABTS ·+ radicals scavenging assays were 139.45 μg/ml, 119.17 μg/ml, 147.65 μg/ml, and 135.83 μg/ml respectively . It could be inferred that MSD showed appreciable in vitro antioxidant activity and could be useful in preventing and ameliorating diseases in which free radicals are implicated

Genetic Analysis of Effect of Heat Stress on Genomic DNA from Cowpea ( Vigna unguiculata (L) Walp.)

Aims: Genetic analysis was used to study the effect of heat st ress on young seedlings of cowpea ( Vigna unguiculata (L) Walp.). Study Design: Four different colors of cowpea seeds (white, dirty w hite, deep brown and light brown) were obtained from GeneBank of International Institute of Tropical Agriculture (IITA) Ibadan, Nigeria. Seeds from each of the cowpea four colors we re first pre-germinated and young seedlings subjected to DNA extraction. Extracted DNA subjected to different temperature treatments at 75°C and 100°C for one hour and control not heated. Place and Duration of Study: Department of Chemical Sciences Afe Babalola University Ado Ekiti, Nigeria between January 2015 and June 2015. Methodology: UV wavelength absorption spectrum analysis (A 200 – A 960 ) was carried out on control DNA and DNA heated at 75°C and 100°C respectively. Cl uster analysis of optical density (OD) data was carried out to establish the relationship between co ntrol DNA and heat treated DNA (75°C and 100°C). Results: DNA concentrations of Vigna unguiculata (L) Walp. were between 0.40 to 1.15 mg/ml, 0.33 to 0.84 mg/ml, and 0.26 to 0.89 mg/ml for control a nd heat treatments of 75°C and 100°C respectively. DNA UV absorption spectra of control and heat treatments of 75°C and 100°C were generally different due to differential UV wavelengt h absorption. Cluster analysis revealed three different clusters (cluster 1, cluster 2 and cluster 3) among control DNA and heat treated DNA. Cluster 1 comprised of V1-control, V1-75°C and V1-10 0°C, with V1-75°C and V1-100°C having similar characters. Cluster 2 was made up of V4-control, V4-75°C and V4-100°C, with V4-75°C and V4-100°C having the same characters. Cluster 3 was largel y characterized by dissimilar DNA extracts of V3-75°C, V2-control, V3-100°C, V2-100°C, V 3-control and V2-75°C. Conclusion: Genetic diversity among individual Vigna unguiculata (L) Walp. accession DNA as obtained in this study could possibly be as a result of variations in heat tolerance among dissimilar cowpea genomic composition

Evaluation and potential of Double Immunodifusion Gel Assay for serological characterization of rice yellow mottle virus isolates in West Africa

Rice yellow mottle virus is not only highly infectious to rice plants but also a highly variable pathogen. Forty-two isolates were obtained from five countries in West Africa. Utilizing 26 polyclonal antisera, the serological diversity of these isolates was determined using Double Immunodifusion Gel Assay. All the antisera were classified into three serogroups, PSg-1a, PSg-1b and PSg-2. Antisera belonging to PSg- 1a, PSg-1b and PSg-2 serogroups had diagnostic potential of 86-90%, 69-76% and 52-64%, respectively, for the 42 RYMV isolates analyzed using a dilution of up 1:200. Moreover, all isolates were separated into three serogroups, Sg-1a, Sg-1b and Sg-2. The first two groups are widely distributed across West Africa. The high diagnostic potential exhibited by the 26 RYMV polyclonal antisera indicates that Double Immunodifusion Gel Assay is useful and reliable for diagnosing RYMV. As the use of ELISA (Enzyme- Linked Immunosorbent Assay) is expensive and unavailable in most of the national agricultural research institute in West Africa, they can adopt Double Immunodifusion Gel Assay for the identification and characterization of Rice yellow mottle virus isolates. This is the first phylogenetic analysis report on the use of Double Immunodifusion Gel Assay to characterize Rice yellow mottle virus isolates in West Africa.African Journal of Biotechnology Vol. 4 (2), pp. 197-205, 200

Full Length Research Paper - Evaluation and potential of Double Immunodifusion Gel Assay for serological characterization of rice yellow mottle virus isolates in West Africa

Rice yellow mottle virus is not only highly infectious to rice plants but also a highly variable pathogen. Forty-two isolates were obtained from five countries in West Africa. Utilizing 26 polyclonal antisera, the serological diversity of these isolates was determined using Double Immunodifusion Gel Assay. All the antisera were classified into three serogroups, PSg-1a, PSg-1b and PSg-2. Antisera belonging to PSg- 1a, PSg-1b and PSg-2 serogroups had diagnostic potential of 86-90%, 69-76% and 52-64%, respectively, for the 42 RYMV isolates analyzed using a dilution of up 1:200. Moreover, all isolates were separated into three serogroups, Sg-1a, Sg-1b and Sg-2. The first two groups are widely distributed across West Africa. The high diagnostic potential exhibited by the 26 RYMV polyclonal antisera indicates that Double Immunodifusion Gel Assay is useful and reliable for diagnosing RYMV. As the use of ELISA (Enzyme- Linked Immunosorbent Assay) is expensive and unavailable in most of the national agricultural research institute in West Africa, they can adopt Double Immunodifusion Gel Assay for the identification and characterization of Rice yellow mottle virus isolates. This is the first phylogenetic analysis report on the use of Double Immunodifusion Gel Assay to characterize Rice yellow mottle virus isolates in West Africa