IAA-Producing Penicillium sp NICS01 Triggers Plant Growth and Suppresses Fusarium sp-Induced Oxidative Stress in Sesame (Sesamum indicum L)

( Radhakrishnan ),( Ramalingam ),( Kang Bo Shim ),( Byeong Won Lee ),( Chung Dong Hwang ),( Suk Bok Pae ),( Chang Hwan Park ),( Sung Up Kim ),( Choon Ki Lee ),( In Youl Baek ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.6

Application of rhizospheric fungi is an effective and environmentally friendly method of improving plant growth and controlling many plant diseases. The current study was aimed to identify phytohormone-producing fungi from soil, to understand their roles in sesame plant growth, and to control Fusarium disease. Three predominant fungi (PNF1, PNF2, and PNF3) isolated from the rhizospheric soil of peanut plants were screened for their growth-promoting efficiency on sesame seedlings. Among these isolates, PNF2 significantly increased the shoot length and fresh weight of seedlings compared with controls. Analysis of the fungal culture filtrate showed a higher concentration of indole acetic acid in PNF2 than in the other isolates. PNF2 was identified as Penicillium sp. on the basis of phylogenetic analysis of ITS sequence similarity. The in vitro biocontrol activity of Penicillium sp. against Fusarium sp. was exhibited by a 49% inhibition of mycelial growth in a dual culture bioassay and by hyphal injuries as observed by scanning electron microscopy. In addition, greenhouse experiments revealed that Fusarium inhibited growth in sesame plants by damaging lipid membranes and reducing protein content. Co-cultivation with Penicillium sp. mitigated Fusarium-induced oxidative stress in sesame plants by limiting membrane lipid peroxidation, and by increasing the protein concentration, levels of antioxidants such as total polyphenols, and peroxidase and polyphenoloxidase activities. Thus, our findings suggest that Penicillium sp. is a potent plant growthpromoting fungus that has the ability to ameliorate damage caused by Fusarium infection in sesame cultivation.

New type of inorganic–organic hybrid (heteropolytungsticacid–polyepichlorohydrin) polymer electrolyte with TiO2 nanofiller for solid state dye sensitized solar cells

Radhakrishnan Sivakumar,Krishnasamy Akila,Sambandam Anandan 한국물리학회 2010 Current Applied Physics Vol.10 No.5

A new type of inorganic–organic hybrid solid state polymer electrolyte consisting of hetero-polytungsticacid impregnated polyepichlorohydrin with iodine/iodide and TiO2 nanofiller have been prepared for their potential application in dye sensitized solar cells. The prepared polymer electrolytes were well characterized by FT-IR, Scanning electron microscopy (SEM), X-ray diffraction (XRD), Electrochemical Impedance analysis (EIS) and Thermal analysis (TGA). The prepared polymer electrolyte with TiO2 nanofiller shows reasonable ionic conductivity (20.4 × 10−6 S cm−1) compared to pure polyepichlorohydrin (2.0 × 10−9 S cm−1) at ambient temperature. The presence of negatively charged redox species heteropolytungsticacid in the polymer matrix prevents the photo reduction of iodide (back electron transfer) and the presence of TiO2 nanofiller increases the degree of amorphousity of the polymer which in turn prolongs the stability of the fabricated dye sensitized solar cell over a long period compared to bare polymer electrolyte.

Dilemma of gonial angle measurement: Panoramic radiograph or lateral cephalogram

Radhakrishnan, Pillai Devu,Varma, Nilambur Kovilakam Sapna,Ajith, Vallikat Velath Korean Academy of Oral and Maxillofacial Radiology 2017 Imaging Science in Dentistry Vol.47 No.2

Purpose: The purpose of this study was to evaluate the accuracy of panoramic imaging in measuring the right and left gonial angles by comparing the measured angles with the angles determined using a lateral cephalogram of adult patients with class I malocclusion. Materials and Methods: The gonial angles of 50 class I malocclusion patients (25 males and 25 females; mean age: 23 years) were measured using both a lateral cephalogram and a panoramic radiograph. In the lateral cephalograms, the gonial angle was measured at the point of intersection of the ramus plane and the mandibular plane. In the panoramic radiographs, the gonial angle was measured by drawing a line tangent to the lower border of the mandible and another line tangent to the distal border of the ascending ramus and the condyle on both sides. The data obtained from both radiographs were statistically compared. Results: No statistically significant difference was observed between the gonial angle measured using the lateral cephalograms and that determined using the panoramic radiographs. Further, there was no statistically significant difference in the measured gonial angle with respect to gender. The results also showed a statistically insignificant difference in the mean of the right and the left gonial angles measured using the panoramic radiographs. Conclusion: As the gonial angle measurements using panoramic radiographs and lateral cephalograms showed no statistically significant difference, panoramic radiography can be considered in orthodontics for measuring the gonial angle without any interference due to superimposed images.

Romidepsin (depsipeptide) induced cell cycle arrest, apoptosis and histone hyperacetylation in lung carcinoma cells (A549) are associated with increase in p21 and hypophosphorylated retinoblastoma proteins expression

Radhakrishnan, V.,Song, Y.S.,Thiruvengadam, D. Masson Pub. USA, Inc 2008 BIOMEDICINE AND PHARMACOTHERAPY Vol.62 No.2

Histone deacetylase inhibitor such as romidepsin (depsipeptide, FR901228, FK228) is a promising new class of antineoplastic agent with the capacity to induce growth arrest and/or apoptosis of cancer cells. However, their precise mechanism of action is uncertain. Histone acetylation and deacetylation are involved in transcriptional activation and transcriptional repression, respectively. Romidepsin induced histone hyperacetylation can be correlated with the cell cycle arrest and apoptosis. In the present study, we investigated the effects of romidepsin on cell proliferation, cell cycle arrest, apoptosis and histone hyperacetylation. Expression of Cdc2/Cdk-1, cyclin B1, cyclin A, p21/Cip1, pRb, pRb2/p130, histone H4 and H3 acetylation status were studied with western blot analysis. The induction of apoptosis has been demonstrated by annexin V-FITC binding assay. Extent of apoptosis has been assessed measuring the activity of caspase-3. Romidepsin led to substantial decrease in the expression of Cdc2/Cdk-1, cyclin B1 and phosphorylated pRb and increase in p21. The pRb protein was found to be one of the targets for the romidepsin induced cell cycle arrest. Flow cytometric analysis showed that romidepsin induced cell cycle arrest at G2-M transition, with significant induction of apoptosis at 25 and 50nM concentration of romidepsin, with an increase in the number of both early and late apoptotic cells. From this study it is concluded that romidepsin inhibit advanced human lung carcinoma (A549) cell proliferation by altering the expression of cell cycle regulators and apoptotic protein.

In silico Analysis of Natural Compounds as Modulators of Type I Collagen

Radhakrishnan Narayanaswamy, Lam Kok Wai, Norhaizan Mohd Esa, Intan Safinar Ismail 조선대학교 기초과학연구원 2016 조선자연과학논문집 Vol.9 No.3

Collagen plays a vital role in the maintenance of structure and function of a human body. It has been widely applied in various fields including biomedical, cosmeceutical, food, pharmaceutical and tissue engineering. In the present study, the docking behaviour of type I collagen with 15 different ligands namely hydroxymethylfurfural, methylglyoxal, methylsyringate, O-methoxyacetophenone, 3-phenyllactic acid, 4- hydroxybenzoic acid, kojic acid, lumichrome, galangin, artoindonesianin F, caffeic acid, 4-coumaric acid, origanol A, thymoquinone and quercetin was evaluated along with their putative binding sites using Discovery Studio Version 3.1. Docking studies and binding free energy calculations revealed that origanol A has maximum interaction energy (-40.48 kcal/mol) and quercetin with the least interaction energy (-15.44 kcal/mol) as compared to the other investigated ligands. Three ligands which are galangin, methylsyringate and origanol A were shown to interact with Asp21 amino acid residue of chain B (type I collagen). Therefore, it is strongly suggested that the outcomes from the present study might provide new insight in understanding these 15 ligands as potential type I collagen modulators for the prevention of collagen associate disorders

Physiological and biochemical perspectives of non-salt tolerant plants during bacterial interaction against soil salinity

Radhakrishnan, R.,Baek, K.H. Elsevier Science B.V., Amsterdam. 2017 Plant Physiology and Biochemistry Vol. No.

<P>Climatic changes on earth affect the soil quality of agricultural lands, especially by increasing salt deposition in soil, which results in soil salinity. Soil salinity is a major challenge to growth and reproduction among glycophytes (including all crop plants). Soil bacteria present in the rhizosphere and/or roots naturally protect plants from the adverse effects of soil salinity by reprogramming the stress induced physiological changes in plants. Bacteria can enrich the soil with major nutrients (nitrogen, phosphorus, and potassium) in a form easily available to plants and prevent the transport of excess sodium to roots (exopolysaccharides secreted by bacteria bind with sodium ions) for maintaining ionic balance and water potential in cells. Salinity also affects plant growth regulators and suppresses seed germination and root and shoot growth. Bacterial secretion of indole-3-acetic acid and gibberellins compensates for the salt-induced hormonal decrease in plants, and bacterial 1-aminocyclopropane-1-carboxylate (ACC) deaminase synthesis decreases ethylene production to stimulate plant growth. Furthermore, bacteria modulate the redox state of salinity-affected plants by enhancing antioxidants and polyamines, which leads to increased photosynthetic efficiency. Bacteria-induced accumulation of compatible solutes in stressed plants regulates plant cellular activities and prevents salt stress damage. Plant-bacterial interaction reprograms the expression of salt stress-responsive genes and proteins in salinity-affected plants, resulting in a precise stress mitigation metabolism as a defense mechanism. Soil bacteria increase the fertility of soil and regulate the plant functions to prevent the salinity effects in glycophytes. This review explains the current understanding about the physiological changes induced in glycophytes during bacterial interaction to alleviate the adverse effects of soil salinity stress. (C) 2017 Elsevier Masson SAS. All rights reserved.</P>

Optimization of Cutting Parameters for Turning Al-SiC(10p) MMC Using ANOVA and Grey Relational Analysis

Radhakrishnan Ramanujam,Nambi Muthukrishnan,Ramasamy Raju 한국정밀공학회 2011 International Journal of Precision Engineering and Vol. No.

This paper presents the detailed experimental investigation on turning Aluminium Silicon Carbide particulate Metal Matrix Composite (Al-SiC –MMC) using polycrystalline diamond (PCD) 1600 grade insert. Experiments were carried out on medium duty lathe. A plan of experiments, based on the techniques of Taguchi, was performed. Analysis of variance (ANOVA) is used to investigate the machining characteristics of MMC (A356/10/SiCP). The objective was to establish a correlation between cutting speed, feed and depth of cut to the specific power and surface finish on the work piece. The optimum machining parameters were obtained by Grey relational analysis. Finally, confirmation test was performed to make a comparison between the experimental results and developed model and also tool wear analysis is studied.

Fuzzy-based Field-programmable Gate Array Implementation of a Power Quality Enhancement Strategy for ac-ac Converters

Radhakrishnan, N.,Ramaswamy, M. The Korean Institute of Electrical Engineers 2011 Journal of Electrical Engineering & Technology Vol.6 No.2

In the present work, a new approach is proposed for via interconnects of semiconductor devices, where multi-wall carbon nanotubes (MWCNTs) are used instead of conventional metals. In order to implement a selective growth of carbon nanotubes (CNTs) for via interconnect, the buried catalyst method is selected which is the most compatible with semiconductor processes. The cobalt catalyst for CNT growth is pre-deposited before via hole patterning, and to achieve the via etch stop on the thin catalyst layer (ca. 3nm), a novel 2-step etch scheme is designed; the first step is a conventional oxide etch while the second step chemically etches the silicon nitride layer to lower the damage of the catalyst layer. The results show that the 2-step etch scheme is a feasible candidate for the realization of CNT interconnects in conventional semiconductor devices.

Spermine Promotes Acclimation to Osmotic Stress by Modifying Antioxidant, Abscisic Acid, and Jasmonic Acid Signals in Soybean

Radhakrishnan, Ramalingam,Lee, In-Jung Springer-Verlag 2013 Journal of plant growth regulation Vol.32 No.1

Ameliorative effects of spermine against osmotic stress through antioxidants and abscisic acid changes in soybean pods and seeds

Radhakrishnan, R.,Lee, I. J. POLISH ACADEMY SCIENCES WARSAW 2013 ACTA PHYSIOLOGIAE PLANTARUM Vol.35 No.1