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Madhaiyan M.,Tamilnadu Agricultural University | Madhaiyan M.,National University of Singapore | Poonguzhali S.,Tamilnadu Agricultural University
International Journal of Systematic and Evolutionary Microbiology | Year: 2014

Two strains of Gram-negative, methylotrophic bacteria, isolated because of their abilities to promote plant growth, were subjected to a polyphasic taxonomic study. The isolates were strictly aerobic, motile, pink-pigmented, facultatively methylotrophic, non-spore-forming rods. The chemotaxonomic characteristics of the isolates included the presence of C18: 1ω7c as the major cellular fatty acid. The DNA G+C contents of strains BL36T and BL47T were 69.4 and 69.8 mol%, respectively. 16S rRNA gene sequence analysis of strains BL36T and BL47T placed them under the genus Methylobacterium, with the pairwise sequence similarity between them and the type strains of closely related species ranging from 97.2 to 99.0 %. On the basis of their phenotypic and phylogenetic distinctiveness and the results of DNA-DNA hybridization analysis, the isolates represent two novel species within the genus Methylobacterium, for which the names Methylobacterium pseudosasicola sp. nov. (type strain BL36T=NBRC 105203T=ICMP 17621T) and Methylobacterium phyllostachyos sp. nov. (type strain BL47T=NBRC 105206T=ICMP 17619T) are proposed. © 2014 IUMS.


Manimaran P.,Directorate of Rice Research | Ramkumar G.,Directorate of Rice Research | Sakthivel K.,Tamilnadu Agricultural University | Sundaram R.M.,Directorate of Rice Research | And 2 more authors.
Biotechnology Advances | Year: 2011

Genetically modified crops are one of the prudent options for enhancing the production and productivity of crop plants by safeguarding from the losses due to biotic and abiotic stresses. Agrobacterium-mediated and biolistic transformation methods are used to develop transgenic crop plants in which selectable marker genes (SMG) are generally deployed to identify 'true' transformants. The commonly used SMG obtained from prokaryotic sources when employed in transgenic plants pose risks due to their lethal nature during selection process. In the recent past, some non-lethal SMGs have been identified and used for selection of transformants with increased precision and high selection efficiency. Considering the concerns related to bio-safety of the environment, it is desirable to remove the SMG in order to maximize the commercial success through wide adoption and public acceptance of genetically modified (GM) food crops. In this review, we examine the availability, and the suitability of wide range of non-lethal selection markers and elimination of SMG methods to develop marker-free transgenics for achieving global food security. As the strategies for marker-free plants are still in proof-of-concept stage, adaptation of new genomics tools for identification of novel non-lethal marker systems and its application for developing marker-free transgenics would further strengthen the crop improvement program. © 2011 Elsevier Inc.


Shanmugam S.,Tamilnadu Agricultural University | Kjaer K.H.,University of Aarhus | Ottosen C.-O.,University of Aarhus | Rosenqvist E.,Copenhagen University | And 2 more authors.
Journal of Agronomy and Crop Science | Year: 2013

This study analysed the alleviating effect of elevated CO2 on stress-induced decreases in photosynthesis and changes in carbohydrate metabolism in two wheat cultivars (Triticum aestivum L.) of different origin. The plants were grown in ambient (400 μl l-1) and elevated (800 μl l-1) CO2 with a day/night temperature of 15/10 °C. At the growth stages of tillering, booting and anthesis, the plants were subjected to heat stress of 40 °C for three continuous days. Photosynthetic parameters, maximum quantum efficiency of photosystem II (PSII) photochemistry (Fv/Fm) and contents of pigments and carbohydrates in leaves were analysed before and during the stress treatments as well as after 1 day of recovery. Heat stress reduced PN and Fv/Fm in both wheat cultivars, but plants grown in elevated CO2 maintained higher PN and Fv/Fm in comparison with plants grown in ambient CO2. Heat stress reduced leaf chlorophyll contents and increased leaf sucrose contents in both cultivars grown at ambient and elevated CO2. The content of hexoses in the leaves increased mainly in the tolerant cultivar in response to the combination of elevated CO2 and heat stress. The results show that heat stress tolerance in wheat is related to cultivar origin, the phenological stage of the plants and can be alleviated by elevated CO2. This confirms the complex interrelation between environmental factors and genotypic traits that influence crop performance under various climatic stresses. © 2013 Blackwell Verlag GmbH.


Daisy A.,Tamil Nadu Agricultural University | Kamaraj S.,Tamilnadu Agricultural University
Journal of Microbial and Biochemical Technology | Year: 2011

With the aim of improving knowledge about the stability and reliability of anaerobic night soil treatment systems, several researchers have studied the effects of different digester design and operational performance of such digester. In general, anaerobic digesters are affected by changes in external factors, but the severity of the effect is dependent upon the type, magnitude, duration and frequency of the imposed changes. Special attention is paid to the advantages of anaerobic digestion in limiting the emission of greenhouse gases This review summarises the causes, generation rate of night soil, composition of slurry, pathogen and its harmful effects and effects of operation in different digester on anaerobic night soil treatment systems. However, there still remain some unclear technical and scientific aspects that are necessary for the improvement of the stability and reliability of anaerobic processes. An overview of research achievements and future developments is given. © 2011 Daisy A, et al.


Ramasamy S.,Madurai Kamaraj University | Velmurugan G.,Madurai Kamaraj University | Rajan K.S.,Madurai Kamaraj University | Ramprasath T.,University of Alberta | Kalpana K.,Tamilnadu Agricultural University
PLoS ONE | Year: 2015

Physiological cardiac hypertrophy is an adaptive mechanism, induced during chronic exercise. As it is reversible and not associated with cardiomyocyte death, it is considered as a natural tactic to prevent cardiac dysfunction and failure. Though, different studies revealed the importance of microRNAs (miRNAs) in pathological hypertrophy, their role during physiological hypertrophy is largely unexplored. Hence, this study is aimed at revealing the global expression profile of miRNAs during physiological cardiac hypertrophy. Chronic swimming protocol continuously for eight weeks resulted in induction of physiological hypertrophy in rats and histopathology revealed the absence of tissue damage, apoptosis or fibrosis. Subsequently, the total RNA was isolated and small RNA sequencing was executed. Analysis of small RNA reads revealed the differential expression of a large set of miRNAs during physiological hypertrophy. The expression profile of the significantly differentially expressed miRNAs was validated by qPCR. In silico prediction of target genes by miRanda, miRdB and TargetScan and subsequent qPCR analysis unraveled that miRNAs including miR-99b, miR-100, miR-19b, miR-10, miR-208a, miR-133, miR-191a, miR-22, miR-30e and miR-181a are targeting the genes that primarily regulate cell proliferation and cell death. Gene ontology and pathway mapping showed that the differentially expressed miRNAs and their target genes were mapped to apoptosis and cell death pathways principally via PI3K/Akt/mTOR and MAPK signaling. In summary, our data indicates that regulation of these miRNAs with apoptosis regulating potential can be one of the major key factors in determining pathological or physiological hypertrophy by controlling fibrosis, apoptosis and cell death mechanisms. © 2015 Ramasamy et al.


Swamy G.J.,Kongu Engineering College | Sangamithra A.,Kongu Engineering College | Chandrasekar V.,TamilNadu Agricultural University
Dyes and Pigments | Year: 2014

The aim of the study was to investigate the influence of independent process variables like extraction temperature, time and mass of beetroot on the aqueous extraction of betalain from beetroot. The optimum conditions for the aqueous extraction of betalamic acid, betaxanthin and betacyanin from beetroot were performed using a three-factor and three-level Box-Behnken design under response surface methodology. The pigments were extracted from beetroot at temperature (40-70 °C), time (30-90 min) and mass of beetroot (0.5-1.5 g) using water as solvent. The data obtained from the experiments were analyzed by Pareto analysis of variance. Further, the data was fitted to a second-order polynomial equation using multiple regression analysis. The optimal conditions based on both individual and combinations of all responses (extraction temperature - 60°C, time - 84 min and mass - 1.5 g) were found out. At this optimum condition, the total betalamic acid, betaxanthin and betacyanin content were found to be 9.9 mg/100 g, 16.3 mg/100 g and 30.9 mg/100 g with desirability value of 0.999. The experimental values closely agreed with the corresponding predicted values. © 2014 Elsevier Ltd. All rights reserved.


Balakumbahan R.,TamilNadu Agricultural University | Rajamani K.,TamilNadu Agricultural University | Kumanan K.,TamilNadu Agricultural University
Journal of Medicinal Plants Research | Year: 2010

Acorus calamus (Sweet flag) is a wetland perennial monocot plant, in which the scented leaves and rhizomes have been traditionally used medicinally against different ailments like, fever, asthma, bronchitis, cough and mainly for digestive problems such as gas, bloating, colic, and poor digestive function. Number of active constituents and essential oil were identified and characterized from the leaves and rhizomes of sweet flag. An over view of the pharmacological activities and insecticidal activities are summarized here. © 2010 Academic Journals.


Mythili R.,TamilNadu Agricultural University | Venkatachalam P.,TamilNadu Agricultural University | Subramanian P.,TamilNadu Agricultural University | Uma D.,TamilNadu Agricultural University
Bioresource Technology | Year: 2013

Biomass is a renewable resource utilized to produce energy, fuels and chemicals. In this study, 25 bioresidues were selected and the physical, chemical, thermal and elemental analyses of the residues were studied as per standard methods. The bioresidues were pyrolyzed at 450. °C in a fixed bed reactor to produce biooil. Among the residues, paper (pinfed computer) and Parthenium produced maximum (45%) and minimum biooil (6.33%), respectively. Arecanut stalk, redgram stalk, rice husk, wheat husk, maize cob, coir pith, Cumbu Napier grass Co5, Prosopis wood and paper resulted in a better biooil yield. Models were developed to predict the effect of constituents of bioresidues on the yield of biooil. The volatile matter and cellulose had significant effect on biooil yield. Biooil thus obtained can be used as fuel that may replace considerable fossil fuels. © 2013 Elsevier Ltd.


Chitra R.,Tamilnadu Agricultural University | Rajamani K.,Tamilnadu Agricultural University
Research Journal of Medicinal Plant | Year: 2010

Gloriosa superba is a medicinal climber, its seeds and tubers contain valuable alkaloids viz., colchicine and colchicoside as the major constituents, which are used to treat gout and rheumatism. Eighteen accessions of Gloriosa superba collected from various geographical regions of the important Gloriosa growing states viz., Tamil Nadu and Andhra Pradesh were evaluated for total sugar, starch, protein, total phenol, peroxidase, catalase and poly phenol oxidase at Horticulture College and Research Institute, Tamil Nadu Agricultural University, Coimbatore to assess its suitability for seed yield as well as tolerance to leaf blight. The accessions exhibited remarkable variations for all the traits studied. The maximum peroxidase, catalase and minimum poly phenol oxidase were observed in GS 15 while GS 12, recorded the highest total sugar content. The accession GS 15 excelled in the accumulation of starch, soluble protein and total phenol in tuber and thus can be utilized for extraction of colchicine and colchicoside. © 2010 Science Alert.


Preetha G.,Tamilnadu Agricultural University | Stanley J.,Tamilnadu Agricultural University | Suresh S.,Tamilnadu Agricultural University | Samiyappan R.,Tamilnadu Agricultural University
Chemosphere | Year: 2010

The green miridbug, Cyrtorhinus lividipennis, an important natural enemy of the rice brown planthopper (BPH), Nilaparvata lugens plays a major role as a predator in suppressing the pest population. The study assessed the impact of certain potential insecticides used in the rice ecosystem on the miridbug predator and brown planthopper through contact toxicity. Eleven insecticides, including neonicotinoids, diamides, azomethine pyridines, carbamates, pyrethroids, organophosphates and cyclodienes were selected to test their toxicities against the nymphs of C. lividipennis and N. lugens. Median lethal concentration (LC50) was determined for each insecticide using an insecticide-coated vial (scintillation) residue bioassay, which revealed BPMC as the highly toxic chemical with an LC50 of 0.003mga.iL-1 followed by ethofenprox and clothianidin with LC50 of 0.006mga.iL-1 at 48 HAT against C. lividipennis and ethofenprox as the highly toxic chemical with an LC50 of 0.009mga.iL-1 followed by clothianidin with an LC50 of 0.211mga.iL-1 at 48h after treatment (HAT) against N. lugens. Among the insecticides tested, the cyclodiene compound, endosulfan had the lowest acute contact toxicity (LC50=66.65mga.iL-1 at 48 HAT) to C. lividipennis. Among the insecticides tested, endosulfan, chlorpyriphos, acephate and methyl parathion are regarded as safer to C. lividipennis based on selectivity ratio, hazard quotient and probit substitution method of risk assessments. © 2010 Elsevier Ltd.

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